Hello all. Well i have made the decision to do an inframe overhaul on my Cat 426 Backhoe and have already run into a major stoppage. I started pulling off all the items i could get to before removing the head. The water pump is mounted on a base/housing that attaches to the head. There are 4 bolts that holds that part on. So you would think that one could just remove those 4 bolts and the head would be free to just remove it? Well no BC the water pump is mounted on that housing and there is one bolt INSIDE that housing that also holds the housing to the head and only way to get to it is remove the WP. So had to take off the fan guard and thought i could unbolt the water pump from the housing and just lift the pump and fan out? Turns out that the fan will not go forward enough to let the pump impeller clear the housing, so now i can not get that last bolt out. It looks like there is no way to get the fan/pump combo out of the way without pulling the radiator? So if anyone has ever done this and has a solution i would greatly appreciate any help on it. Oh yes, i did think of that service manual thing but would have to float a loan to buy it. LOL
Maybe this will help. Not sure what exactly you have without a serial number.
Thanks, this does cover my machine SN 7BC00580. I do need that info included in that attachment, it has everything i need to know such as torque specs etc. Much appreciated. I really need info prior to where your attachment starts, ie how to remove the fan and water pump as a unit. Or at least get the fan off. Problem with that is the fan is too close to the radiator to get your hand and wrench in there to remove those bolts out that fan to the pump. The attachment shows the head removal and appears to have the water pump and housing still attached to it. But how did they get the fan off?
this should help. Are you computer savvy, @Rocket Man ?
Very much so. Been in computers since early IBM 360 days. Univ of Wyoming 1969. Thanks for the files. I am still in limbo BC i still can not figure how to get fan off. No room to get tool in front of it where the 4 bolts are that attach it to the water pump. Your pump removal illustration starts out with the fan already removed. So, it looks like the illustration for removing the radiator is a prelude to getting the fan off the water pump. ? Guess that is my next task. BTW, next item is how to replace the fan belt. LOL. Looks like one has to completely remove the Hydraulic Pump drive shaft.
I replaced my drive belt. I removed the rubber coupling. @Rocket Man I sent you a PM
GREAT INFORMATION!! I never knew that was a rubber coupler, looks like metal four bolts on each end and close tolerance to boot. But since it is rubber it wont be so hard to do. It actually has a 2 belt capacity but has been running with one but i want to add the other belt along with the new alternator. That water pump is my greatest headache right now.
if you don't have A/C you only have one belt, the alternator. The other grooves on the crank and water pump are for the optional A/C compressor. When I did my belt I replaced the rubber coupler. I bought them aftermarket for much less. Looked identical to original.
You are a wealth of good information. Your input is very much appreciated. Interesting about those belts. Mine does not have A/C but the alternator i just bought has a double pulley. I will have to work on this one. Yes to aftermarket stuff, but only those things that can be accessed and replaced easily. The hard ones like the water pump, oil pump etc i will spend the extra money on them.
If you can get both belts to line up I would put them on. V-Belts used to be sold in matched pairs for this type of installation. Been years since I owned anything with V-belt so not sure if you can buy them like that now or not. Certainly don't mix brands. I am not big on aftermarket parts. For critical stuff I only use OEM stuff. If I can save 50% or more on aftermarket and it looks well made, fits and is in a non-critical area than why not? FWIW the coupler had the identical markings in it as the original. Probably made by the same vendor, just without the Cat markup. I am far from an expert. I just have been working on and off on my Cat 426 and spent a ton of time studying pictures, manuals and the machine itself.
Yes, i have seen some of your posts and i can tell you that you provide much needed information. I am going thru what you have already done, in most cases. I am determined to figure out how to get that fan and pump out as one piece. I am sure no manufacturer in their right mind would make something so difficult to replace/repair. So given that , there has to be a way to get it out. The attached pics tell the story. The first one shows the fan blades are bottomed out on the radiator and second one shows the water pump wedged against the housing. It needs about 1/2 inch to clear! Anyway, if you ever need to change the water pump this will give you some insight into it.
With the water pump installed, you can usually get a combination wrench on one of the bolts to break it loose, then rotate to another opening between the blades and crack the next loose and so on. Usually fingers and knuckles are sliced by the radiator tubes but- no pain, no gain . Once the bolts are backed out, the fan, with the bolts still inserted, but free from the pulley, can usually be manipulated out. Sometimes the shroud and fan may have to be removed together if the shroud is bolted to the rad. I'm not saying this will work but may be worth a try if there's enough room
Great idea and it would normally work out where the fan fits flush with the front of the pump. But if you will look at the pics you can see the pump actually fits into the fan recess of about 3 inches. So even if i got the bolts out the fan would not come out. lol Gonna keep trying.
Oh yes, i wanted to ask you if you took the whole assembly out? ie both rubber couplers or just one? Thos bolt look like they will be hard to get out.
If the shroud is bolted to the rad( i can't tell) unbolt the shroud and lay it back over the water pump. Then reach in through the side or top between the rad and the shroud to lift out the fan and then lift out the shroud. Usually there is a way unless you have to tip the whole rad assembly forward
The shroud is a wire mesh two piece shroud and the left half is off. The fan blade is flat, then you have the spacer and then the pulley. The paint or corrosion might be holding the fan blade and spacer in place. I would put the water pump back on and then remove the 4 bolts holding the blade to the pulley. Then you should be able to slide the fan blade and pulley out the side. Typically if I remove a fan of that style I would leave the V-Belt on to help hold the pulley so I could break the fan bolts free. Put a piece of cardboard over the radiator fins to protect them and your knuckles. The hold the pulley either have a helper hold it with a big pair of channel locks or put Vise Grips on the edge of the pulley so it will hit the water pump housing to lock it in place. You will have to move the fan for each bolt. If I still needed more clearance I would probably remove the radiator mounting bolts to get the extra clearance I need. Here are pics from the parts manual.
OK took it off and it did not help because the shroud bolts onto a raised lip on the radiator. I will bolt the pump back on and try that again. Edgephoto posted some diagrams that helped me see some things i can not see from here. The fan is actually composed of 3 parts , the fan, the pulley, and the spacer. At first i thought that it was all one piece making it impossible to get out without pulling radiator.
OK. Thanks, my manual skipped class when these were handed out. Now i see that there are 3 parts to that fan thing. I will bolt the pump back on , put the cardboard in there ( i will still loose lots of skin and blood) and then take the fan loose. That may allow the fan to slide out the side and then i can break out the spacer and finally the pulley. I have to say its something i would never expect of a big company to screwup on. Big error in my opinion.
I am not a heavy equipment specialist. I am a Field Service Engineer for a major car manufacturer. I have wrenched on vehicles professionally one way or another since 1985. Most of the same principles apply. Electricity is electricity, engines are engines. Just have to figure out how a manufacturer does things. When I did the belt I replaced both of the rubber couplings. I removed the hex shaped metal piece first, then both coupler. (see the red circle in the photo). I then loosened the pinch bolt on the pump flange and moved it back and forth on the splines. Used a bit of Kroil on this. Then I installed the rubber couplers and finally I tightened the pinch bolt. It was not too bad to do. I have done worse jobs. Most stuff on this machine is metric. You may want, if you don't already own, get a set of Gearwrench ratcheting combination wrenches. I have the flat ones you flip over for reverse. I like these because they are smaller and fit in place the ones with reversing lever won't fit. I use a standard box end to break them free and then go to the Gearwrenches to remove the bolts.
Now this the kind of detailed instructions i am talking about. With this i can just walk into it and gete'r done. When i first looked at this, all i saw was solid steel spacers and shuttered because they are hard to get in and out. OH yes, i do have just about every wrench that can be bought (but can never find them when i need them). I know to do the job you MUST have the right tools. BTW, my machine which is the 1987 426 is ALL SAE, no metric anywhere. Strange that yours is metric. Also, i am not a mechanic either. I am actually a retired Company Financial Controller that grew up on a cotton farm in New Mexico before running off to college. Why do i do these things? BC, dont wanna sit on my butt and die from boredom. So today i removed all the head bolts and tried to pick up head and discovered i am no where near as strong as i would like to be, as in 10 years ago. That head weighs 90 lbs bare. It still has the pump housing and the exhaust manifold attached so it must weigh over 100 lbs. Will attack again tomorrow after i have my oatmeal. LOL
I am sure no manufacturer in their right mind would make something so difficult to replace/repair. Rocketman, I haven't read anything that funny in a long time. I owned a Jaguar repair shop for 30 years & I can tell you that you couldn't be more wrong. One of the funnier lines in Jag repair manuals was "maneuver clear" -- actually means get a cutting torch, it ain't coming out of there. Joe H
@joe--h Funny you mention stuff like that. We put in our manuals, "remove all items necessary to facilitate removal". In other words "we have no idea how to do this repair because we never tried, good luck". Experience pays off because I can look at stuff and know how to take it apart. I bought the service manual for my machine but have hardly used it. Mostly to look up specs.
I agree with all that you are saying . I wonder who actually writes the manuals because some of it really makes no sense at all. Anyway, just to follow up on that fan removal project. I determined that a cutting torch would indeed solve the issue. I tried taking the approach that was suggested by a couple of you guys and discovered that the fan has SIX blades which makes it impossible to get ones hand in there. I got the gear wrench in and got one bolt loose until the gear wrench would not ratchet anymore, it just moved the bolt in and out in the same place. I could get a finger in there but could not move the bolt. So i just gave up and pulled the head off and i will replace the WP while it is all apart. IF i ever have to replace that WP in the future i will just cut one blade off the fan and be done with it. I am thinking that a 4 bladed fan would be better? Anyway, i will re-assemble it all in reverse order.
I has to wonder, can't the cooling stack be tilted forward, like I've done on my A and C model backhoes?
thanks for the input and i have posted some pics of this impossible task. The radiator is sitting in a position that requires it to be lifted straight up and out to get it out of the way. There is is this big heavy duty oil cooler attached to the front of the radiator that has to come loose first. So even if you take all the bolts out of the radiator it can not go forward because of the two mounting ears in front of it. So has to come up and out, the first pic shows the mount that welded to the frame., one on each side. Pic 2 shows the bottom mount, one on each side. Funny how this machine was put together. Pic 3 shows the heavy duty oil cooler mounted in the front of the radiator.
Today I was able to get the oil pan off and man is that thing heavy. It was really stuck on there. Had to take a hammer and pry bar to get it loose. Can't say for sure but it looks like the engine has never been worked on, the rod bearings are in good condition considering the age of it. The rod bearings are STD and marked with a Perkins number (31126311) and i believe their logo.? The real problem so far is the compression ring on the one piston i pulled out was in about 20 or more pieces. See pics. I will buy a complete kit as soon as i can determine what LINERS i have. That brings me to a question some you might be able to answer. My engine SN is LD70201U128179A and according to what i have read about it is it a "late" engine of that series. Seems simple enough but then the kits specify or ask which LINERS i have and that where the problem starts. Here are the 3 options the seller says are available: Plain, Press Fit, Unfinished 103.2mm Flanged, Slip Fit, Pre-Finished 103.2mm Flanged, Slip Fit, Pre-Finished 104.2mm I thought that it being a late model and a specific engine number would indicate which liners were in there but guess i was wrong. I think i can eliminate the first one because i can see that the sleeves in there have a flange at the top. See pics. So the question is how do i tell if i have the 103.2MM or the 104.2MM.?
Maybe you could measure your existing liners with a dial bore gauge. I also wonder if the liners are stamped on the other end? ** Be sure to get all the coolant out of those threaded holes for the head bolts before you go back together with it. The hydraulic compression can do bad things to the block.
Yes to cleaning out those bolt holes. Now i have a another mystery that needs solving. My machine is a 1986/7 Cat Backhoe 426 and SN is 7BC00580 and my ESN is LD70201U128179Aand each part of this number stands for something. The last LETTER is A and is supposed to be for the year of manufacture. According to all the charts i have seen the A is for either 1974 or 1995. So question is could this be right? I am pretty sure it is not 1974 so can this be a 1995 engine? Makes a lot of difference when ordering parts. Any help is appreciated. Year of Manufacture Code A 1974 G 1980 N 1986 W 1992 D 1998 K 2003 T 2009 B 1975 H 1981 P 1987 X 1993 E 1/1/99-3/31/99 L 2004 U 2010 C 1976 J 1982 S 1988 Y 1994 F 4/1/99-12/31/99 M 2005 V 2011 D 1977 K 1983 T 1989 A 1995 G 2000 N 2006 W 2012 E 1978 L 1984 U 1990 B 1996 H 2001 P 2007 X 2013 F 1979 M 1985 V 1991 C 1997 J 2002 R/S 2008 Y 2014
According to what I see in the SEPB1569 parts manual your machine needs piston ring kit 7W-7732. Your engine takes liner 7C-3182. Maybe @Nige can verify my work.
Well, after considerable research and a long conversation with a Cat Representative i am now ready to explain the mystery Serial Number thing. Recall that my ESN as stamped on left side of block is LD70201U 128179 A. I passed this number to the Cat Rep who said their system does not recognize that number and it "must be" a Perkins number. ? Yes it is, but Perkins PARTS website does not recognize it either. Anyway, i gave the Machine number to the rep and he came up with the original ENGINE Serial Number on my machine of , get this, 00128179 . Looks familiar BC that number is actually part of the ESN stamped on the block. No one knows how the "A: got on the end of the ESN OR why Cat added two zero's as a prefix. So i guess the engine was actually made on a Monday. LOL. Now another mystery to me was WHY some Perkins engines parts are listed with a prefix before the 4.236. ie, A4.236, C4.236, T4.236 etc. So, here is how that comes about. It is hard to buy parts without knowing which is which. A Air Cooled D Direct Injection G Gasoline W Water Cooled C Compensated E Electric T Turbo My engine is the C4.236 BC it is just a plain old Diesel engine and no turbo. Most of you probably already knew all this but i just wanted to put it in writing for those of us who didn't know and or who was not listening in Perkins Class.
Just doing some quick Googling it seems these liners are cheap. If it was me I would just put in new liners, rings and bearings in the lower end and have a machine shop check the valves and guides. Put new springs on and reassemble. I would also send out the injectors to have them checked and rebuilt. Then she will purr like a Cat.
Thanks. I got that info from the Cat Rep today BUT that 7C3182 actually (apparently) has two versions, a slip sleeve and a press sleeve. In addition one has a " fire dam" and the other doesn't. I am to pull a sleeve out to get the actual number off it as that number is stamped on the sleeve. I have a sleeve puller coming and i will then know what to order.
New set of injectors coming from UK and will obtain complete inframe rebuild kit, once i get the right size liner identified. Have located a local machine shop that has a fair reputation for rebuilding heads. I may or may not use them, will know after in go in person there. My kit has all new valves, guides, spring etc and the head will be milled. Not gonna take a chance here and get it done right. That way this thing will last a long time.
That seems odd. I have never seen a part number with two versions. It would have a different part number. Otherwise it is impossible to differentiate in the warehouse. I am no Cat or parts specialist. I just have been in the auto service business for 36 years. Getting the number off the original sleeve would be the best bet. Then you know which ring set you need. Maybe you can see the piston part number?
Yes to the piston part number. The one piston i have out and cleaning up has a number but can't really make it out. Once i get them all out i can piece a good number together. Here is something odd, the piston has 4 rings BUT they are are all above the wrist pin. That is weird BC all the replacement ones i see so far do have 4 , 3 above the wrist pin and one on the skirt below the pin. I don't really know which one is correct.
on engines with dry liners, they can be hard to pull so that is why they are usually heated and shrunk first by welding or by oxy-acetylene torch. i prefer the welding method. one of the liner part numbers is likely for an oversize liner if the block has to be honed due to the bore being out-of-spec
This is what the parts manual shows.
That could be the case. The parts book just lists two liners, one bigger than the other and i guess they did that just to show the NON STD was available?
Thanks for that info. My parts manual has about the same picture BUT does not show a part number for the piston. It just says "piston serviced separately". LOL One way for them to cover all the bases i guess.
BTW. I have read about that welding method but am reluctant to try it as i am not that good at this welding thing. Afraid i will burn a hole in the block and then i would really be in a fix.
Low heat(amps) and move the bead fast. The liners are usually around 3/32" or less thick
Well, t i only have a wire welder. Would that work? I have only read where someone used a stick welder, been years ago tho. So if a wire welder will work how many passes do i make and i assume its from top to bottom?
Sure, just move fast enough to leave a bead top to bottom in about 4 to 6 places. If 4 isn't enough, do more. Don't touch the deck surface-you don't want ANY marks on the deck from welding. Flux-core wire will likely penetrate deeper so be carefull. If the crank is still in the block, it has to be protected- preferably with a piece of tin to shed the spatter and sparks. You Do NOT want any foreign material in the oil passages in the crank. Before any reassembly and after welding and cleaning the bores, i like to use a solvent suction-type air nozzle and rinse the inside of the crankcase. Make sure there are no foreign particles, etc on and around the cam and followers. You can't be too clean
Good advice. Thanks so much. I am going to try to pull the sleeves without the welder thing just to be safe. I have the time to spare. LOL. So if the puller becomes too difficult then out comes the welder and will try my luck. 10-4 on protecting all that vital stuff. When i retired in 07 i went into rebuilding old Ford tractors, 2N, 8n, and 9N's and they all had sleeves. The 40MM i could just drive a screwdriver down the side and they would just break out like glass. The 90MM ones were more difficult and had to pull them. I had a disc of stainless steel built by my neighbor machinist and it was perfect. Had a 5/8" all thread and i could pull one out in 5 minutes. Installation took longer because had to drive them in. That is until i started using dry ice and then they just dropped in. I rebuilt 30 of them in 10 years and every one of them presented different problems. Got to admit, this is first diesel i have ever done. Lots of special care i have to take compared to a gas engine. I am going to do it right so it will be like original and last a lone time. I believe everything in this engine is just like it came from the factory. I am installing an electric heater this time so NO MORE ETHER. The PO had ruined the engine long before i bought it and every piston in it was broken. Every compression ring and all other rings were broken as well. I do not know how it even ran as long as it did. That heater is Zerostart/Temro #3100093 which has the 3/4" NPT threads that just screw into the water pump housing where the Ether Assist plug used to be. The element on it is very short and fits nicely into the housing. The one that actually fits in the block behind the starter is a real pita to install #3100013. So i opted to take th easy way out.
I rebuilt my '57 ford 850 and the sleeves were glued in...what a treat they were to get out...
Yes, they use LocTite red to set them in place. If you put them in dry they will work loose sometime especially on those old tractor engines.
Ok i am back at it again. Had to take a break from this engine rebuilding so i could get other things done. After resuming my engine project i have discovered that i have many other problems than first thought. I thought that getting parts would be simple and i could just order them and finish the job. First off, recall that i was having trouble identifying the parts i would need. Turns out that my ESN leads me to an engine identified as a Perkins C4.236 as opposed to a regular 4.236. That "C" stands for "Compensated" and Perkins says it was "lightly turbocharged". I wondered what that meant and found some pics of a C4.236 on the net and sure enough it DID have a small turbo on it. HOWEVER, mine does NOT and by the looks of the intake and exhaust manifold , it never did have a turbo. So, i am now stuck on which parts to order and a couple of questions i have that probably can be easily answered by some of you who have been there and done that. BTW, the inframe overhaul kit for the C4.236 is almost double that of the one for the regular 4.236 engine. I don't know why because i have done a comparative analysis and the only difference i can detect is in the Piston/sleeve kit. Are the sleeves so different that it would cost that much more? So, my question is, how do i proceed without knowing if i have a C4.236 or a regular 4.236. ? I suspect that the difference lies solely in the type of sleeves each engine has. Hopefully someone can verify that for me.
I don't know about your particular motor but I always thought that there is a difference in turbo charged pistons and naturally aspirated. I think that turbo pistons are forged for greater strength. There are other differences to. IMHO.
Turbocharged variants of naturally aspirated engines usually have lower compression ratios and oil jets to cool the pistons. This means either different piston pin height or a dish in the top. I went through the same problems trying to source parts for an old NA Deere 4239. The rebuild kits were cheaper and more plentiful for the Turbocharged variant.
Your machine Serial Number is 7BC00580 and Engine S/N 00128179, correct.? If so, according to the Parts Manual it was originally built with a turbocharger. Hence why it's a labelled as a C4.236 rather than a straight 4.236 engine Looks like someone in the past has ***ked with it. So what do you propose to do, return it to original turbo spec or continue to rebuild it as a naturally-aspirated engine.? You'l need to consider what to do with the injector pump, injectors, and a whole host of other parts including maybe pistons & cylinder head if you decide to go non-standard. EDIT: Just had a look somewhere else and now I'm not 100% sure. Let me dig a bit more & see what I can come up with. EDIT 2: Well that didn't take long. By the engine Arrangement Number (7C-6075) your engine was definitely built as a non-turbo. Apologies for any confusion. The Parts Manual can take you off in two different directions and I originally only looked at one of them. Attached is the Bill of Materials for 7C-6075.
You may be right and i would use them if it doesn't make any difference, ie they are the same size. The rebuild kits do not say and trying to find out is futile. I have called 2 distributors and neither one could tell me the difference. It is like they are all on remote control. Maybe guarding a secret? lol.
Nige, thanks so much for all your hard work on this. I have reached the point where the brick wall is and i just can not get past that. I appreciate the attached list as that will help me out. Now i have to extrapolate from that list and find a rebuild kit that corresponds to it. Anyway, you are not the only one who identified it as a C4.236. Every rebuilder i have talked to said the same thing, "it is a C4.236. " I could see no evidence this machine was ever turbocharged. No oil line connection, hood configuration for the turbo etc. So given all that i was in a pickle on ordering parts and did not want to make a big expensive mistake by getting the wrong ones. So, what you are saying is that the engine i have is just a straight 4.236 made after the ESN U106655N? Also would you say that all these Perkins 4.236 's have the same size piston? Maybe the Turbo ones have a heavy duty one?
Why not just buy the parts from Caterpillar themselves instead of aftermarket?
They can not identify the engine i have. LOL They tell me to go to Perkins because they do not stock parts for that engine which they say is a C4.236. So that is why i am not buying from them. I have found a very good company that specializes in making Perkins engine parts, Maxiforce and they have very good feedback. They are are all made in America and apparently have excellent quality control. They do not sell directly to public but have lots of distributors and that's the ones i have talked to. Again, they all want to sell me parts for a C4.236 engine BC that is what the engine SN says. It is hard to find someone with common sense who can "talk Turkey" and understand what i am looking for BC that engine is NOT a C4.236, no matter what the ESN says. They all have this go by the book mentality, which is what we are all taught to do. I just tried to identify the piston by the number i found on the piston and rods. Perkins tells me "there is no match" . LOl and get this, right next to the numbers is the word "PERKINS" stamped into the metal. Can't figure that one out.
Just to bring my dilemma into perspective, here is a list of "possible" engines mine could be. I have to keep in mind that the only thing so far that will or is supposed to, identify my engine is the ESN, LD70201U128179A which is incorrect. 4.236 > 236U147150L - U106654N, 2.769 4.236 > After 236US24720L, 2.769 4.236 > After U106654N, 2.763 4.236 > After U106654N, 2.769 4.236 > After U106654N, 3 ring pistons, 1.375 4.236 > Thru 236U147149L, 2.753 4.236 > Thru 236US24720L, 2.753 4.236 > Thru U963999L, 3 ring pistons, flanged liners w/ fire dam, 4 bolt balancer 4.236 > Thru U963999L, 3 ring pistons, straight liners, 4 bolt balancer 4.236 > U964000L - U106654N, 3 ring pistons, flanged liners w/ fire dam, 6 bolt balancer 4.236 > U964000L - U106654N, 3 ring pistons, straight liners, 6 bolt balancer I think i have narrowed it down to this one because my pistons have 3 rings and this is the only one that has three rings. All the others seem to have 4 and 5 rings. I wonder if that would even make a difference? 4.236 > After U106654N, 3 ring pistons, 1.375
@Nige gave you the engine number. The parts manual I sent you has the parts list for your machine. You could provide the part numbers yourself. Maybe @Nige could help you get the Cat part numbers figured out for what you need? I usually provide my dealer with the part numbers I want. Usually I place the order online and just pick it up in my travels. Nearest Cat dealer to me is 40 miles but I am on the road a lot for work. So far everything I have looked up for my machine using the parts manual has been correct. This being said I have not ordered engine parts. I am doing the engine maintenance last.
So i took the piston GP number of that list Nige sent me and plugged it into Perkins and no matches. Did same thing on Cat and no match. Keep in mind the serial number on my engine appears to be invalid. Post #28 explains the components of the serial number. The suffix "A" indicates the year of mfg., in my case it would be 1974 or 1995/ Neither of which would even come close to matching the contents of the rest of the serial number. It's going to be interesting to see what happens when you start on your engine. Hopefully you won't have this nightmare i am having. BTW, refer to my post #32 to see what happened when i looked up liners.
So how come I can find it..? Below is the illustration for 7W-2790 Rod & Piston Gp. 7W-2790 is NOT sold as a single number. It comprises 10 different line items, each one of which has to be bought separately. Piston Assembly (with pin/retainers but minus rings - Items 1-4 inclusive) is 4W-5819. Piston Ring kit (per piston - Item 5) is 7W-7732.
Do you have a good photo of the Serial Number plate from your engine.?
Thanks for your input.
Here is pics of it.
Here is a better pic.
The original engine for the machine S/N is listed as "128179" in the Cat system. That's the same engine as the one on the plate IMHO. So the engine appears to be original and will date from anywhere from 3-6 months before the build date of the loader (18th Dec 1986). As I see it you have a few possible options from here on in:- 1. Use the Parts Manual SEBP1589 that @edgephoto shared with you and buy parts from a Cat dealer based on Cat Part Numbers. Don't ask the dealer to find a specific number for you, give it to him. 2. Continue down the route of trying to find Perkins parts based on the engine Serial Number. Random comments from the photo regarding the interpretation of the engine Serial Number:- 1. I don't think the last letter is an "A". It looks almost like an upside-down "V" because the "crossbar" part of the "A" is missing completely. So I wouldn't put too much emphasis on the Year Code being "wrong" based on the YOM of your loader. 2. "LD" at the start of the number is the Code for a basic 4.236 engine. If it was a C4.236 it should be "LH" or if it was a T4.236 (full-blown turbo) then it would be "LJ". 3. The "U" in the middle signifies it is a UK-built engine. Correct if it was built for a Cat BHL. All the engines for the Cat BHL product line are still built in Peterborough to this day.
OK. I magnified that number on my screen and u r right, it is not an A, it is an N that was stamped at an angle and the other leg missed the nameplate area and is barely visible off plate. I was not able to see that detail until i spray painted the number this morning. That N signifies the year 1986, which is the right year. Thanks to all of you here for all the input and parts numbers etc. I have been able to compile enough info to be able to buy the right aftermarket kit now. I have been buying all my parts from Cat so far and the prices are reasonable, hydraulic hoses , radiator hoses etc. but the engine hardware, not so much. One piston is $190+ and one set of rings $85+. One after market rebuild kit $600+. So not much contest there. One other question comes to mind: how does the Cat BHL compare to the Perkins line? I wonder if any of the parts are the same or interchangeable? Just curious.
Perkins is/was purely an engine manufacturer, they never built complete machines. Cat selected Perkins to supply the engines for the original line of Cat backhoe loaders such as yours back in the 1980's. In 1998 Cat bought Perkins outright and the engines for the smaller Cat machine lines (BHL, SSL, MTL, etc) supplied from the former Perkins factory in the UK became known in the trade as "Perkapillars" - still built at the Perkins plant but with Cat logos on them. AFAIK most if not all Perkins engines supplied to other OEMs apart from Caterpillar are still badged as Perkins today.
I don't plan on touching my engine unless something happens to it. It runs, does not smoke and sounds fine. If I do have to tear it down and replace parts I will measure the sleeves for taper and round. If in spec. I will measure the pistons. If they are in spec. I would hit the cylinder with a light hone and re-ring. Why replace the hard parts if they are still serviceable. Although if the $600 kit includes all gaskets and seals as well as rings, pistons and sleeves it might be worth it. Providing the parts are of good quality.
You are very lucky by having a good engine. These things are really awesome and if taken care of will last for decades. We are looking at 35 year old machines and still running. I can tell you these engines are tough!! After all that ether and bad treatment by the PO, the cylinders in mine really do not look that bad. At first they looked in good shape and were glazed over pretty bad. I then used a hone and found lots of vertical grooves in number 1. I could not see the grooves before the honing. That # one could have been honed out with minimal loss of the walls. Number 2 was a total loss. The first few ups and downs revealed not only the vertical grooves but it was egg shaped as well. So bottom line is i have no choice but to replace them all. I installed my puller on #1 and it is stuck. It crushed my wooden space blocks and never moved. Today i will drag out the welder and go that route. They should come out easily. Now the anticipatory fear is replacing them. On the old Ford tractors the walls were only 90mm and i would dry ice them, coat the cylinder walls with Loctite red and drop them in. Sometimes i had to finish off with a block of wood and hammer. But these Perkins liners are much thicker and may not be so easy. Now, my question is, would you go back with the 3 ring piston or the 4 ring piston? There is a choice and either piston will work. I am getting my kit from an American firm and products made in USA. (So it is said). Kit that is recommended comes with the 3 ring pistons. But i can substitute to one which has the 4 ring pistons.
Do the farmers carry out artificial insemination of cattle around your way.? If the answer is yes then you ought to be able to rent a container of liquid nitrogen which is the mutt's nuts when it comes to installing shrink-fit parts such as your cylinder liners. Just be careful - it's f'kin cold (-320F).
Nige, good idea! I never thought of that, just the dry ice. I will double check on that. Don't know about the cows but there are lots of race horse farms here and they probably do the same thing. Also, they use that liquid nitrogen in the oil fields which are not far away.
An old trick is to steam-clean the cylinder block while the liners are chilling in the LN2. The combination of the expanded block with the shrunk liners means you have to be careful the liner doesn't fall straight through the hole when it is installed.....
H Ha that would be funny, except it would be tough getting them back out. Luckily mine have the wide flanges at the top so they can't fall thru. I will pressure engine cause i don't have a steamer.
I just wanted to post an update on the engine rebuild on my Cat 426 Backhoe. I was waiting on my parts to come in and took forever to get them it seems. Complete rebuild kit including upper and lower gaskets, many of which won't be used because it is an "inframe" rebuild i am doing. Bought all the extra items i thought i would need and many i will not use. For example, i bought a new OIL PUMP, but won't use it BC you can not get the pump out without pulling the front crankshaft pulley and cover off. I checked the crank shaft rod areas and they were exactly what the manual said they should be at standard. The good part of this is about the sleeves. Took lots of effort to get the sleeves out as they were really stuck in there. After i got them out and checked the part number on them i understood why, maybe. There are two sleeve types, one that is finished and ready to go and the other is the one that can be installed but requires machine finishing AFTER they are installed. Mine had the last one and apparently they maybe had a closer tolerance fit? So i bought the one that was finished and ready to install. I used DRY ICE to cool the sleeves down before installation. ( I wanted to use liquid nitrogen which is plentiful here BUT no one had containers to go with it, No rentals either. You are required to furnish your own.) I used about 40 lbs of dry ice to completely cover the sleeves and let then stay in the crushed ice for 30 minutes per sleeve. Results were surprising, the first one just dropped in all way to the flange. The second one hung up at about 1/4 inch in and had to work it back out. I skipped that one to be the last as it was going to be trouble. The third one dropped in to about the last inch and had to pound it in rest of the way. The fourth one dropped in perfectly. Now back to the trouble one #2. Left the sleeve in the dry ice for 30 minutes or so and took a deep breath and tried again and it just dropped in all the way to the bottom. Problem was, it has to be started PERFECTLY straight immediately Or it will hang up. Here is a hint on buying dry ice. I went to the source of dry ice production thinking it would be cheaper. It cost me $250 per pound. I happened to be in that all encompassing big store (next day) that sells everything and guess what, they had dry ice for $1.25 per pound. So check your local grocery store for dry ice, it will be somewhere close to the customer Service area in a freezer that looks like an ice cream chest. Name on it is Penguin.
Hello all. I now have a big mystery on my hands and am turning to you all to maybe help me out. These pics are of a piece of metal i found under my back hoe engine and i have no idea what it is. It is one piece and the pics are the front and back. Recall that i have been doing an inframe engine overhaul and have completed all the tasks i set out to do. I have reinstalled the pan, head and most major components. I am taking my time and cleaning things up as i go. As i was installing a new alternator i dropped a small nut in the dirt and was using a magnet to find it when i latched onto the above "clip". It is about 2 1/8 inches outside diameter and 1 inch inside diameter. It kind of looks like a "thrust" spacer/washer but is way to small. Looks like it might be some kind of retainer? The raised slots on the outside tells me that it is designed to maybe fit into a recessed area? Anyway it was laying directly under the rear part of the engine and as you can see it it not rusty and looks fresh out of a moving past area. Since it is fresh looking i can only assume it came from my engine? Any help would be greatly appreciated.
It looks like 1/2 of a crankshaft thrust washer to me.
Yes it does resemble one, except it is way to small. ID of the one in the pic is only 1 inch and OD of crank shaft is 2 1/2 inches. It is more likely to have been a shim for a cam shaft, but they don't come in half circles. All the ones i have ever seen are full circles and fit onto the cam shaft as it is installed, usually in the front behind the "sprocket".
OK, here are the pics again but more to actual scale as i have set them against a quarter to show the actual size. This will give a more realistic view and maybe trigger some recognition. I am beginning to doubt that it came from my Perkins Engine and that deepens the mystery as to exactly what is the item and where did it come from? Driving me crazy. If it does belong in the engine and is an essential part i will have to tear the engine down again. I just can not imagine where it might fit in.
I'm beginning to agree. Looks nothing like a crank shaft thrust bearing from your engine. Looked right through the parts pictures... front structure, alternator, oil pump, starter, camshaft, fan hub, etc, found nothing that looks like that (unless I'm blind, which is possible). Any witness marks or wear if you look really closely?
I agree that it certainly is too small to be crankshaft thrust washer. But it sure has the appearance of one.
The only marks are the circular ones on it that indicate it indeed is a "shim" or "thrust" washer of some kind. I too looked at the parts manual for everything from engine to differential and there is not a pic of this item. I know it did come from this machine BC there ground it is sitting on was brought in from my "back 40" by this very machine and when it is sitting right where it quit running. I did pressure wash the entire machine right where it sits and maybe that piece was laying on the machine somewhere ? BUT, it WAS directly under the motor as if it had fallen straight down from the engine. BTW, i went to alibaba and pulled up all pics of thrust washers and never found a likeness of this one. LOL Anyway, i believe i have been convinced that it is NOT from the engine and it is safe to finish the re-assembly. Thanks to all.
Well i completed the re-assembly and all went well. Bled the air out of the fuel system and it fired right up instantly. Runs like a top !! Thanks to all with all the great advice and support.
Nice work. How about a few pictures?
Ok, here are some pics of that backhoe. I still have to install springs for the brake pedals as when i apply the brakes the pedals do not come back up. I can not seem to locate where the springs were originally, if any. Anyway, here are some pics. Note that i installed the heater in the port just behind the Injector Pump.
Ran out of space so here are more pics.
Total cost which includes items that were not needed and i replaced them anyway was about $2800 and i did all the labor. I replaced the entire exhaust manifold system (2 pieces), alternator, water pump, new (rebuilt) injector pump, lots of new bolts and screws, new fuel pump, fuel lines, all radiator hose, belts, and some of the shorter hydraulic hoses.
Wow, i completely missed that spring mainly because I was looking for a long spring that is typically used for the brake pedal return. Thanks for that photo. I will take a look tomorrow. Mine must be broke and by the looks of it, not easy to replace.
Depending on Serial Number the setup might look more like this. The one posted above is for real early serial numbers.
I went by serial number
Thanks for the drawings. I did look up this on my flash drive and completely missed the "curl" springs and i do not know which ones i have until i get a better look after tear down. According to the serial number they list , mine would be the "curl" type in the I think it would be faster and more effective to just install the long springs i had in mind. It would not hurt for sure, BC it will take hours to tear down and replace the factory ones. Yes, this is for the serial numbers after mine. In both cases it looks like cat made a bad design for these springs. Should have been one that we can just replace and attach it on both ends with bailing wire like we used to on the farm.
Check all the brake linkage to make sure it is free. Don't forget the handbrake linkage. On mine the linkage was frozen causing the brakes not to work.