hi, my 1st post here Rebuilt engine just installed by pros, oil pressure is low idle=20-25psi, 2000rpm=30-40psi. I did the build but the pro was supposed to run the engine before the install. There were comm. problems with his employees so it did't get started until after. What's done is done, now i have to manage the issue. This cat has no oil-pr gauge, only a low-pr horn which remains silent. Is this an urgent issue or can i wait for spring? The oil pump relief-bypass is accessible with oil pan removal, is it a very likely suspect? Changing the pump requires front cover removal i think. More than that requires engine removal. I may need guidance material for the engine removal/installation, does anyone know of any. I have the service manual but it's no help for this. thanks for any words of wisdom
No words of wisdom from me . But, a couple of questions if I may. There are too many unknown conditions to recommend a pump or relief spring replacement IMHO. You are saying you did the rebuild of the motor but you had someone else install it, is that correct ? Do you have the service manual for it ? If you do what are the specs. for the oil pressure ? A high of 40 psi seems a little low but not bad. Were the bearings checked with a plasti-gauge when they were installed ? What weight oil is in it ?
The pro removed the engine and also reinstalled it as I was not well equipped for that. I built it but didn't have all the accessories with it for a startup. It seemed like a no brainer for him to do the first start. I had packed the new pump with petrol jelly though some crank turning probably got in there before the first start. There are two manuals involved, the cat-426 and the perkins which is a pretty sad excuse for a manual. The perkins states MINIMUM 30psi *at rated power*, 37psi if a 'turbo' engine. The engine is a "C"4.236 which stands for 'compensated'. It has a turbo but only some of the turbo engine parts, like pistons. I suspect that technically I could be safe but 'minimum' still seems like not that great on a new build. I was hoping to hit on some Perkins gurus who might tell me not to worry because that engine is a notorious low-pressure one. The oil is 15w40, all the bearings were double plasti guaged using both the red and green side-by-side for a complete picture, all tightly in specs. Crank, cam, all were very close to new specs. The engine could have done without a rebuild actually. I 'should' have checked the bypass valve but didn't as i was not aware of any history. I had never touched a perkins before but I also built a cummins 5.9 more or less at the same time and it gives 80psi cold 60 psi hot at high idle.
Were all bearings replaced or measured? By all that means camshaft, rocker arms and the rocker shaft(s)? Was the oil pump rebuilt, gear clearances and end clearances checked? New relief valve spring(s)?
What oil pressure did it have pre overhaul? I have that same 4-236 engine in a MF50. Oil pressure went to zero. Pulled the pan & cleaned the relief valve & shimmed it with a couple (I think) washers. Now has 70# at idle. Too much shim but not pulling that pan again. I think you can get the pump off without removing the front cover, just don't mess up the timing on those counter weights. Clever of them to put the relief valve in the pump instead of somewhere accessible. And I have the ** factory manual. Sorriest excuse for a manual you can find. Joe H
Except for he cam all new bearings, new piston pin bushings. The head s complete & new just did the lash. The oil pump was complete & new. Didn't touch the relief, should have because at least I would now know that it wasn't IT.
Thanks, now at least I now know that the engine will pump 70psi so there's little doubt left that my 40 psi just isn't good enough. It'll make the winter but it's gotta get fixed in the spring. And yeah, that's a pan and a half ain't it? I've never thought of using jacks just to take a pan off, hehehe! The Perkins 'manual' you gotta go through the whole thing each time you wanna find something. I didn't check the pressure before the build, the 426 has no gauge only a horn.
To get detailed specs needs a Cat Serial Number, but I looked at a 426 at random and found this regarding the lube system relief valve .......... Pressure setting (when the valve should lift) ... 345 to 415 kPa (50 to 60 psi)
thanks, looks like it might have an obstruction stuck in it or, more likely, a weak spring. Is it possible for a spring to weaken THAT much?
That info may be incorrect for your machine, I picked it at random. Need a machine Serial Number to get correct info for your particular engine
Yes a S/N sure would help get good answers! As I'm not real familiar with the engine, is the relief valve part of the pump or a separate component? If separate very possible it is worn, spring or other parts like the seat or plunger. Should be a standard procedure to inspect seat and test or replace spring when doing a rebuild.
Piece of something stuck in it keeping it open probably. Joe H
The cat is #7BC01181 the engine is # LH70202U168588P and the latter of the two is a real can of worms; many kit suppliers will give you the WRONG pieces for it as I have found out.
From what I see in the glorious Perkins manual the pump output leaves it via a pipe to a delivery/relief block bolted to the bottom edge of the crankcase. The valve is in that block and not in the pump so it's accessible with a pan removal. Relief should trip @ 50-60/70-80 psi for normally-aspirated/turbo engines. Doesn't say boo about compensated engines but i'd be happy with either figure. And yeah, with perfect hindsight I 'should' have checked it.
The information I found before is correct for your machine Serial Number 7BC01181 - see below. Like other posters above I can't believe that tearing down and rebuilding the oil pressure relief valve was not contemplated as part of the engine rebuild. Regarding your engine number - instead of the Perkins S/N on the plate, try using Cat data as follows. Engine model D4.236, S/N 001-68588. It may limit the number of places that would recognize it but should ease your problems of getting wrong parts. BTW the S/N of the driveline installed in your particular machine is 00G-71982.
That was the 8th engine and the third diesel I ever built, that's how. I probably presumed that the valve was integral with the new pump I put in. The entire episode was a nightmare beginning with wrong parts delivered three times and causing a two week delay each time because the source's suppliers would not drop ship, etc. etc. The last beauty was the idiotic angular piston bushing bores that NO machinist who is not an engine specialist is prepared to work with. Getting those bushings in, all by itself, saw me at 4 different shops spending a total of $900 for work alone. I should have bought the complete piston and rod assemblies. I should have, I should have... it never ends. The alternative was a pro build which was quoted at $13,500cdn with a turbo, about 4 times what I spent and I've seen pro builds blowing prestone into the oil too after a few months. Thank you very much! I've put those numbers away. Now that the engine is rebuilt at 7600hrs and seeing that I put 5,500 on it in 15 years, and the fact that I'll be 76 in a few months.... I might not built "it" again Fact is that each time I bought parts through Cat I always got good ones. This time my son gave me a pro rebuilder as a source for MaxiForce kits and that's how it ended up on the non-Cat route. I like the engine, it's a good engine, but the documentation, aaaarrrrrgggghhhh! From what I've been told, at the time they were experimenting with an upgrade when the prototypes, and more than just one, went into Cats being produced in England at the time instead of bin-13, or at least to a restricted circle of some sort, badly documented, whaaaaaaaatever. And so the resultant #'s mess.
Here's the complete "as built" component list for 426 loader S/N 7BC01181.
LH70202U168588P mine is later 31226*U414561U* The first part is the ** serial #, the U is Perkins. Looking at the MaxiForce kit, $400 for the whole thing seems like they must be crap but how was it other than the wrist pin bushings? Joe H
Thanks old timer, I'll save it out for future ref.
I paid like $2300cdn including pistons, rings, all bearings and gaskets., oil pump, complete head and I don't remember what else. I thought it was GREAT kit, especially the way they packed the rings, nice and orderly, makes it a joy to handle them. BTW I was set to spend an evening gapping the rings but I could not find a single one that was out of spec, in fact they were all center-of-spec. Never seen anything like it b4! Definite kudos there EXCEPT for the # fubar AND the kit doesn't have the seal install rings that make life so much easier (my Cummins kit, forget make, had them). I recommend the kit, as a DIY-er mind you, I ain't no pro!
I forgot, with the piston bushings the problem was IMO stupid design, not the bushings. Engineers too often either don't know any better or don't give a muck about what their exotic summersaults are going to mean in the shop!
Sidebar, I don't think pros will need this but on spec that not only pros buzz around here i'll throw it in: I used dry ice to shrink the new sleeves. The advice I got was to bury them for 5 minutes in the ice, etc. WROOOONG! I put them all in the ice and after 5 I started the installs. Well, the last one went in with just two fingers but the first one (after only 5 minutes) needed the sledgehammer at the end (+wooden block OF COURSE). So I don't know, I think if I ever have to do another I'll go for a minimum of 20 minutes in the ice! Dry ice BTW shipped in an styrofoam box is good for three days (I was really surprised).
Dry ice or liquid nitrogen, always a good method of installing bushes without the need for excessive force. The advantage of liquid nitrogen is that it's possible to see when the bush has shrunk to the maximum because the liquid stops "boiling". When there are no more bubbles visible, whatever is in there is at the temp of the liquid, minus 180DegC or whatever it is. Rod bushings there is also the option of placing the rod in an induction heater and so avoid the need for freezing the bushing. Do you think that there might be a connection between the length of time a particular bushing spent in the dry ice, the force required to install it, and the amount of "rework" associated with it afterwards..?
I could not get nitrogen economically here but the dry ice only cost about $70cdn/50lbs shipped via courier from 600 kms away. My concern was evaporation so I ordered 2x 50lbs and was surprised to see that evaporation wasn't an issue at all and that 50 lbs, even after 2 days on the road, was much more than enough. I don't really understand your question, but being no machinist and shooting from the hip I'd guess that the more the cooling the less the distortion during insertion and so the less the necessary reaming. My issue with the piston bushing wasn't with cooling which I used only on the sleeves. I took the rods to machine shops thinking that for them it would be a walk in the park, well it wasn't, because of the 'exotic' design.
Sorry, my misunderstanding. I thought you were talking about the connecting rod bushings being problematic to install without sufficient cooling in dry ice - in fact you were actually talking about the cylinder liners (sleeves). My mistake. Also I wasn't for a moment suggesting that liquid nitrogen would have been a realistic option in your circumstances, simply commenting out loud of the ease in telling when a bushing is 100% shrunk when using it, compared to using dry ice. I think without seeing the issue in detail that the piston pin bushings in the rods would not be something common for a general machine shop, more one that deals with engine rebuilds day-in, day-out. I wouldn't think of ever referring to anything in a Perkins 4.236 as being of an "exotic" design if I'm being honest.
Those tapered rod bushing bores (narrow on top and large at the bottom absent in the normally aspirated models and the like of which (I never saw one before) are exotic in the sense that for me, living in the country, there may be 6-8 machine shops within reach NOT ONE of which specializes in engines. I can see justification for that level of specialization for F1 engines but not for diesels that may be in service anywhere on the planet, including on the high seas. There may be arguments that a good machinist would know how to handle them, I don't think that the machinists I deal with are anything but 'aces' having seen what they are capable of! The first one I approached declined completely saying he wasn't about to touch rods like that, the second one destroyed a bushing before giving up, the 3rd one got a dozen new bushings from me (just in case) and managed to do the job somehow in 4 hours. Weeks and hundreds of dollars went by as opposed to me working a couple of hours on my low-tech bench because the normal (square) bores require little more than a good vise, a hand reamer, and patience.
I've seen the dry ice for sleeves on youtube, don't think anyone mentioned the longer the better. I believe this is the kit I need https://www.tractorpartsasap.com/perkins-a4236-130522.html Some of the youtubes say the sleeves are honed, some say not honed. Seems like a hell of a lot of youtubers don't really know what they're doing but think they do. As to the rods, if I understand you, looking at the rod from the side the top is narrower than the bottom where the wrist pin bushing goes through? In the parts book the rod looks normal, wrist pin bushing is just a bushing & the bore looks square front to back. I have the Massey parts book, another piece of uselessness that lists 2 engines. For engines built to build list LD31226 only, and another for build list LJ31231 only. No explanation as to what the hell that means. The same liner part number fits both engines, BUT there are 2 different sleeves. One is press fit, the other is slip fit with no explanation as to how to guess which one I might need. $100 factory parts book that goes nicely with the expensive useless factory repair manual. I emailed the people at tractorpartsasap.com with my engine # asking which kit I need & they said we're too busy to reply, call us. How hard is it with all the info in front of them to give me an answer? Haven't even started on this & I'm already pissed off. Joe H
That's funny... they had time to sit down & type that out but didn't have time to look up the answer..?? Or was it an auto response?? But on the other hand.. & no disrespect intended.. its not their fault u don't know whatchr doing..
So we're talking about a rod of a similar design to the one in the illustration below if I understand it right. A very common design in my experience on both naturally aspirated and turbocharged engines used in earthmoving equipment and other applications. FFS, how difficult is it to get a "tapered" bush like that one lined up right before installation..? A 2nd year apprentice ought to be able to do that without breaking a sweat. Honing (if necessary) afterwards is simply a matter of having the correct tooling, which reverts back to my comment about a machine shop that does engine work day-in, day-out.
My previous experience with Perkins dry liners was that the "press-fit" liner was the factory original install by freezing the liner so that it dropped straight into the block. Basically IIRC a new cylinder block would be hot-water/steam cleaned as it came from final machining. Immediately it came out the washer the liners were picked out of a bath of liquid nitrogen and dropped straight into the block. I am not sure if these liners were honed afterwards. The "field install" service liners sold to customers (and also used by dealers for in-frame engine overhauls) were known as "slip fit". They were designed to be fitted in circumstances where heating/cooling of the various component parts was not available. Having watched them being fitted by a Perkins dealer mechanic they required no more than a 4lb hammer and a block of hardwood to install. Again to the best of my recollection, these liners had to be honed afterwards. My memory is a bit hazy going that far back. I would be most surprised if the 2 different styles of liner shared the same Part Number.
I cannot comment on what kit YOU might need. MY experience is what I described. Let me tell you that when you have a sleeve half way in when it stops just sliding you're in something very brown and very deep. Be prepared for such an eventuality. I wasn't but I got lucky. Be careful before buying anything because these engines, as good as they may be, have been around for a long time and the 'file' so to speak has become enormous in size. In my case I had the Cat manual engine section covering things that the LAMENTABLE Perkins manual doesn't and vice versa. There's a good page in the perkins manual about the different sleeves and their fits, which is otherwise fine and dandy, but the brain-dead way they put it all together requires you to study just that page for hours! And the same story pops up again and again be it for pistons, for rings or what have you. I had the impression that the manual was just added-to more or less incoherently each time something got changed. As for the inside of the sleeves/liners some need to be bored, others only honed, mine were 'finished inner surface' with nothing to do As for the 'turbo' rods Nige was kind enough to post a drawing, that's the one. The design 'idea' is logical, for any rod, but the practicality is sub-zero! The rebuilder who ordered my kit tried to warn me, he said to just buy the non-turbo rods instead seeing that MY engine was just a 'compensated' one and not a full turbo. I suspect you won't have this issue if you have no turbo. Concerning the emails, I've been noticing this trend myself. On the one hand people don't want to commit in writing to anything, on the other they're getting millions of emails as opposed the good old days when few people took the trouble of hand writing a paper letter. Not wanting to spam this forum at all, I've had (one) OUTSTANDING email exchange with Folley engines and several with my Cat dealer. Once you find a good one stick with them and buy from them, it's worth even a slightly higher price! HTH and good luck
But on the other hand.. & no disrespect intended.. its not their fault u don't know whatchr doing.. Hey Pumpguy, you could have waited until after I've fucked it up to point that out. Joe H
Nige, that's what I thought he was describing. Any thoughts as to the "why" of it? As to the liner part numbers, they have separate numbers for the press & slip fit, but the same liners fit both of the engines - early and late style. Joe H
Ski, my email to maxiparts I gave them the serial number and asked if it was the right kit. They list the sleeve OD, but as the engine is still running I don't know the diameter. They list only 2 kits so 50/50 chance it's the right kit. More research required in the 2 useless books. Joe H
RESEARCH it until your balls fall off! I didn't deal with MaxiForce directly, I dealt with a pro rebuilder in Toronto only because my son reffed me to them and to whom I gave the engine #. I know MaxiForce would not drop-ship directly to my address and when "I" discovered that the pistons, rings and bushings were the wrong ones I had to order the correct ones, period, no return/refund (out about 200 bucks there). If I had gone through Cat none of this would have happened, they never once sent me wrong stuff yet. I don't know what kind of support avails from Massey-F, at least x-check on that side. I got the correct liners first time around, they were the 4.1025" od 'flanged' service liners, as per the page-worth of confusion print on Technical-Data B.3 and B.4. But then I wanted to be sure that super-cooled fitting would work and I had spend a day measuring and remeasuring the bores and reading the cited section in the excuse for a manual twenty times over. Then there were some suggestions to use loctite, I didn't do that either after my mechanic said it was all BS. I did do something that isn't in the book however. When you drop the liners in they bottom out when the ridge at the top seats into the cylinder cutout (make sure it's clean!) But then, if the liner should for any reason begin to tighten into the bottom of the cylinder first then I figured there was a chance of unscheduled protrusion as the sleeve expands with the bottom locked first. So what I did was prepare a lockdown bar with head bolts and lock the top of the sleeve down as soon as it was in the hole thus forcing all expansion from the ridge down. I finally also measured the above-block protrusion all around in 8 quadrants for each of the 4 holes (all were 0-2 thou if memory serves me right).
aaah, the pumpguy i got good advice from somewhere else in another life?
I suspect it's that the top rod-bore surface serves only to pull the piston down and the exchanged top part in the piston-bore that serves on the powerstroke gets to be bigger in trade. Fine and and dandy, for F1 engines but not for the poor slob sent out in the field to do an in-frame lying on his back in a sewage ditch where the engine crapped out.
Talked to tractorpartsasap.com on their chat line. This later kit is the correct kit for my engine number. Sleeves are honed & press fit. Picture doesn't show it but comes with valves & springs. No bearings or thrust washers but that's only another $40 + shipping. The shipping is $12.95 and the kit is $399.00, so the total for the kit and shipping is $411.95, but this does not include the rod and main bearings. Joe H
Have u checked "Reliance" kits.??
No prices on their site, have to become a "dealer" to see the prices. Filled out the information form and got an email they'll call me about a credit application. ********. So, $450 for a Maxiforce kit sounds good enough. Joe H
Sorry folks, forgot about this thread for a while, I put about 300 hours on the engine and it's running good, SURE starts a lot easier even when cold! The oil pressure has crawled back up to about 60psi cold and 40 hot. I intend to open the bottom in maybe 2 years to inspect the bearings and I miggt revisit the relief valve at that time. Thanks for al the guidance.
The elves came & fixed it, can't get any better than that. Joe H
I figure it might be some liquid gasket that got in there somehow, I didn't use any around the pump but some might have got squeezed out from under the pan gasket for example. Some might still be in there.