To follow up on my first thread: HeavyEquipmentForums with the assistance of the community here I purchased a Cat 311B excavator. I’d like to use this thread to ask questions about this machine specifically. For reference the serial number is 8HR00401. Thanks in advance for your help!
First question, I’d like to replace the radio with one that will connect to Bluetooth. (Also, this is a gray market machine so the current radio isn’t useful). I see relatively inexpensive equipment radios on eBay, such as this: https://www.ebay.com/itm/384312014037 Does anyone have experience with the quality and longevity of one of these cheap radios? Any other suggestions? For reference my current radio mounts in the armrest and looks like this:
Ok, I guess nobody likes music, lol! We’ll move on to question 2, if I buy one of those cheap radios I’ll update this thread with the outcome. I need to take the bucket cylinder and one of the main boom cylinders off to have them repacked. Does anyone know what size fittings are used on each of these cylinders? I’d like to buy caps for the hydraulic fittings on the machine side to keep crap out of the system while the cylinders are off. I tried looking in SIS but didn’t find anything useful. Thanks!
Cat should be able to tell u that w the s/n. Probably like a number 8 o-ring face fittings. Other than that take one loose and confirm what style fitting it is and measure it.
What's the S/N.? You've been looking at SIS but we can't until we have that info. Cat usually recommends plastic plugs that are often shown in the D&A procedure for newer machines buit not older ones. Back in the day they probably assumed that any mechanic worth his salt didn't need telling to plug lines ............ Try looking here. 9U-7067, 9U-7088, 276-7018, or 276-0756 should get you what you need. Or talk to your local hydraulic hose supplier. https://parts.cat.com/en/catcorp/ca...ductId:850&filterByEquipment:true&productId:&
Just buy a kit like this. Certainly less expensive than buying singles.
Thanks for the suggestions, guys. The S/N is 8HR00401. I’ll try to get a photo of the fittings on the machine this weekend.
Can't search 8HR in my SIS. It exists but doesn't breakdown Using 8GR, here are the seal numbers.
If it's anything like the 312c the hr is China prefix and gr is the US version.
Gray market machine probably built by Shin Caterpillar in Japan. The hoses and working parts of the machine will be the same as US models. The cabs and comfort items are different and usually not available from a Cat dealer in the US. The key is no parts listing for that serial number in SIS.
John's correct. The 8HR was built in Japan for the local market and was never intended to be exported (officially by Cat at least) outside Japan. There will be nothing in SIS for the 8HR prefix. Use 8GR instead, see below.
Thanks for the additional details. I stopped on my way home and snapped a few pics of the fittings. I think I’ll just order that combo set of caps that was linked earlier if they will work on these fittings.
Let's see other side of bucket cylinder.
As an aside, not sure why but all the hose ends are ORFS, but the male ends are machined different. ORFS caps and plugs will work all day long, but, the Orings are "different" on the machine male sides.
They use oring boss/stor orings. imo that's what all Oring flat face should use but no one asked me.
The threads and profiles are the same as ORFS, BUT, again, for some strange reason, the 10,12, & 16 males have a deeper recess and will leak if a conventional oRing is used. Been there, done that. My 312 was the same way.
I should be able to get pics of the other end of the bucket cylinder today, stay tuned!
Not the other end. A picture of the hose end at the cylinder.
Ok hopefully I got these photos correct?
Also, when is a hose worn to the point it should be replaced preventatively? I have a few with the outer rubber jacket worn through in places.
Not sure why the photo didn’t attach to the last post?
if you're going to use this basically for a hobby machine as opposed to a revenue-earner I'd leave that hose on there until it pops.
I'd change it, even with a hobby machine, it may blow in an inconvenient place to work on it. FWD
If you have hoses that are rubbing against the machine frame there are many types of plastic spiral wrap available on the market to protect them and add a little more to their life.
I thought about splitting this question off into its own thread for more visibility- I finally got the oil analysis results back yesterday from Cat on the samples they collected during the pre-purchase inspection (on 01/07). I wanted to wait to purchase this machine until after I had these results but Cat couldn’t turn them around in a reasonable time. Hydraulic fluid, coolant and swing gearbox all checked out fine. However, they noted the following about both final drives and the engine oil. Final drive- IRON, PQ, CHROME, ALUMINUM, & SILICON ARE SIGNIFICANTLY ELEVATED. PQ INDICATES FERROUS OR IRON PARTICLES IN THE OIL. THESE WEAR RATES CAN BE SOURCED TO DIRT ENTRY, GEAR & BEARING WEAR. CHECK MAGNETIC DRAIN PLUG (IF APPL.) FOR METAL. INSPECT FOR SOURCE OF DIRT ENTRY INTO THE SYSTEM. CHECK FOR ANY SIGNS OF ABNORMAL WEAR OR ANY OPERATIONAL ISSUES. CHANGE OIL AFTER ANY NEEDED REPAIRS ARE COMPLETED AND RESAMPLE AT 1/2 THE REGULAR OIL DRAIN. The inspection report notes that the magnetic plugs were checked with no abnormal findings. My plan was to drain and fill the final drives as preventative maintenance this spring anyway. Now I think I should pop the drive covers off to check the gears for wear and clean the case thoroughly. Where else can dirt enter the drives besides the front cover seal? Any other thoughts? Engine oil- IRON, PQ, CHROME, AND COPPER ARE ELEVATED. HOW MANY HOURS ARE ON THIS OIL? WEAR RATES MAY BE REFLECTIVE OF EXTENDED HOURS ON THE OIL. PQ INDICATES FERROUS OR IRON PARTICLES IN THE OIL. SUGGEST CUTTING OPEN AND INSPECTING THE OIL FILTER FOR VISIBLE PARTICULATES. ALL OTHER WEAR ELEMENT CONCENTRATIONS (PPM) APPEAR NORMAL. OIL & FILTER WERE CHANGED AT THIS SERVICE - RESAMPLE AT THE REGULAR OIL SAMPLE INTERVAL. I don’t know how many hours are on this oil sample and the filter was replaced concurrent with this sample so I can’t check it for an hour listing. The prepurchase inspection tech cut the oil filter open with no unusual findings noted. Should I consider anything other than what Cat recommended with another oil sample at the next oil change?
We used to get high iron as a result of dirt entry in excavator final drives on a regular basis if the machines were either working in water or tracking a lot - or both. Dirt usually enters final drives via the Duo-Cone face seals between the fixed and rotating parts of the FD. You need to make sure the area around the back side of the sprocket is not full of packed dirt then give it a good clean but NOT with a pressure washer which can drive dirt through the seal into the FD. Area of red arrow. Black arrow shows where the sprocket mounts just to give you an idea. Personally I wouldn't consider opening up the final drive to check. Finals are best disassembled when they are off the machine and rotated to that they are facing upwards to make it easier to remove/install everything. Trying to pull covers with the FD on the machine is not really recommended. I'd run the final drive until it was warm, drain the oil, then fill it back to the normal level with diesel. Pick up the machine using the bucket until the track is off the ground and run the final for say 5 minutes, then drain the diesel. If necessary repeat the process. Leave the FD to drain well after the last flushing then refill with the correct grade of oil. Run the final for around 100 operating hours then resample the oil and see what the analysis looks like. I wouldn't hit the panic button about the engine either. As stated you have no knowledge of how long the oil that was sampled was in there prior to the sample being taken. The oil and filter was changed at the time, hopefully the old oil was well hot when it was drained. The only thing I would suggest over & above the SOS analysis is to resample the oil after 50 operating hours from th eoil change and see what the analysis looks like.
Thank you for the detailed reply! I’ll follow your advice here and then we’ll see what the second oil analysis looks like.
As a further thought/suggestion always consider that top quality oils & filters are the cheapest insurance poilicy you can ever buy for a machine. That means I wouldn't recommend using any product where any of the words "farm, tractor, or universal" occur anywhere either in the name of the product or of the store that's selling it. FWIW I think you should stick with this one thread for your excavator unless you get into something specific that merits a separate thread. That way it makes it easy to scroll back pages to see the machine history during your ownership.
I have sampled oil on thousands of machines that were offered up as trade in units. I stopped sampling final drives unless my client request it done because few owners change oils in them in any kind of consistent schedule. They will always read high iron content and changing the oil when the machine is brought in solved that issue. It is my experience though that dirt getting into the rotating joint seals cannot be cleaned out and is for the most part normal. The seals are covered up by metal lips and pressure washing can't get to them. The failure mode is to leak which is obvious on a walk around before shift. Unless you are working in quick sand or constantly in a river bed, there is little to worry about. Change the oil at the recommended intervals and the finals usually last the life of the machine. I totally agree with Nige on the engine oil as well. Extended service intervals and running with dirty air filters make for bad engine oil sample results. Does it mean there is a problem? You have to look at the totality of your inspection on the engine and the machine. How does it start when cold? Is it leaking oil? What do the coolant hoses look like? Does it have an inner and an outer air filter and are they marked in some way to indicate age. Did someone write hours when changed on the engine oil filters? Start out clean with your machine and change all the filters and fluids as indicated on the oil sample reports and then put the machine to work.
So, next question. I’d like to clean up a little of the body damage as overall the machine is clean and in good shape. It looks like Cat used some form of filler over the steel structure? Any suggestions on what to replace the damaged filler with other than regular body filler? The counterweight also has a small dent, which ironically happened just before it was listed for sale. I’m assuming this would be difficult or impossible to repair and I should just ignore it? (If my OCD will let me!!).
It’s slowly warming up here in New Hampshire, I got the bucket cylinder off today so the hydraulic place can pick it up for a rebuild. While I was at it I also removed the two hoses for this cylinder, I figured I might as well replace them since I had the tools out and they were half disconnected. My next question is about the pattern changer (which I think I don’t have). I believe I’m going to have to move the pilot hoses around at the manifold. I was told these hoses might be color coded to assist in setting the right pattern. Does anyone have access to the directions for where to find the nearest manifold and what hoses to swap? Machine serial number is 8HR00401 and I use 8GR00401 to work around the gray market issue. Thanks in advance!
Switch them under the cab there's bulkhead fittings.the pattern changer would be right at the end of the boom. Most the Grey market machines have the 4 position one and you can not get the backhoe style out of it just remove it and repump under the cab is what I did on ours. As for the colors I just figured it out as most where missing.
I had a call from the hydraulic shop today (if you recall they are rebuilding the bucket cylinder that was leaking). They said that on the tear-down inspection they found the rod to be bent about an 1/8” or less but otherwise free of damage. The options they quoted were to rebuild the cylinder with the original rod or rebuild the cylinder and replace the rod. A new rod would cost $700. I explained to the tech what my plans were for this machine and that it wasn’t going to be used commercially. He said that if it was his excavator he’d re-use the existing rod and felt that the slight bend wouldn’t cause any issues during my projects. Any opinions on this? Also, what causes the rods to bend and what can be done as the operator to prevent this from happening? Thanks!
Don't the hydrauliic shop have a press that they can use to straighten the rod.? Or at least to get it closer to straight than it is now.? A rod can be bent by up to 0.125" (3.18mm) measured over any 24" (600mm) section of its length and still be straightened using a press. That is provided a large enough press is avaiable. A rod that is bent close to the eye should not be straightened using a press. Am I correct in thinking that the rod is about 2.5" outside diameter.? A rod of that size should straighten relatively easily. It's recommended that a rod should be warmed in an oven for about 90 minutes before attempting to straighten it. TBH with a rod as small as this one it would probably straighten at room temperature.
That’s a good question, they did not offer straightening the rod as one of the options, and I did not ask. I will give them a call in the morning and inquire if that would be possible. They are one of the largest hydraulic shops in the area so I would have to think they have a press capable of doing that. Yes, you about right on the size. Offhand I think the external diameter of the rod is about 2 1/2 inches as you said.
I know they would probably not be able to get it perfectly straight, but they ought to be able to get it pretty damn close. I guess it all depends where the bend is.
I called and spoke to the service manager this morning, he described the bend as a “sweep” end to end and felt that it was slight enough that he wasn’t sure they could get it any better with the press. He described the rod as in 95% condition and agreed with the tech that I spoke with yesterday that this imperfection wouldn’t be likely to cause any issues under normal use. Hopefully I’ll have the rebuilt cylinder back and ready for installation within a week.
So I am planning to drain and refill the cooling system as preventative maintenance. The SOS sample test stated that the coolant appeared to be nitrate-free and said that, if so, the coolant should be replaced with Cat ELC. If it was not a nitrate free coolant the nitrate level was low and the SCA additive needed to be replenished. Since I have no idea what type of coolant is in there I’m doing a full drain and refill with Cat ELC. I was planning to drain the old coolant, refill with distilled water and run the machine to operating temp. Then drain again and refill with the new coolant. Is this a suitable plan or should I be doing anything else in this process? Outside of cleaning the radiators and straightening any bent fins is there any other cooling system maintenance I should do at this time? Thanks!
Some people buy one of the flushing kits that includes a T fitting you put in a heater hose and hooks up to a garden hose. When the engine is cool, you hook up the hose, turn on the water and watch a bunch of dirty smelly coolant flow out the top of the radiator. Standard coolant is usually green. Cat ELC is a dark read or purple looking stuff. There is some light yellow looking ELC as well. Someone here will know what they actually are and where you can buy it for less than the OEMs charge.
Your plan to flush the system before filling the new coolant sounds fine. John's sounds even better. Broadly speaking....... Green is generally "old school" DEAC (Diesel Engine Antifreeze Coolant). Not recommended. Some nitrited ELC's (including Cat) are red. Some are purple. Nitrite-free ELC's tend to be yellow. I'm sure there will be exceptions to the above generalizations. Remember to make sure that if there are any isolation valves on the engine block for the heater that they are fully open. Also ensure that the heater control is set to max heat when the system is drained. You don't have to use Cat ELC to meet the spec. You only have to use a nitrite-based OAT-type coolant that meets Cat EC-1 specification. Valvoline do one - https://www.sclegacy.valvoline.com/...antifreeze/valvoline-hd-extended-life-coolant So do Prestone - https://prestonecommand.com/product.../heavy-duty-extended-life-antifreeze-coolant/ And Shell (Rotella ELC is the one to look for) - https://www.shell.us/business-custo...iness/products/shell-antifreeze-coolants.html And probably others as well ............
So I got several hours to work on the excavator today, bucket cylinder was reinstalled with new lines. I also changed out the air filters and fuel filter. Which brings me to my first question- Seems like the fuel system got little attention on this machine in the past. I tried to remove the inlet banjo bolt to clean the internal screen but it was on so tight (and probably frozen up) that I couldn’t get it off. How necessary is it to clean this screen on an excavator that’s running well? Secondly, I went to dump the tank sump drain and it must be plugged because it wasn’t flowing at all. Should I take it out to clean/replace it or blow backwards with an air gun? (I have a full tank of diesel onboard). Finally, I took all the belly pans off to clean them and inside the compartments, I believe this is the manifold where I should change the pilot line to swap patterns from Cat to Deere? I’m going to call the dealer’s tech line on Monday and see if they can tell me what colors to switch so I don’t have to guess.
you absolutely need to get the sump working properly. It is the first line of defense and if you put in clean fuel and sump it frequently you will not have a fuel problem going forward. I took a wire to the 120 sump and got it going. I did not need to remove anything.
Yes it is, if you don't have a pattern changer. give them 8GR as the S/No and don't expect too much........... It is a tap installed in the bottom of the tank with a short drain hose on it, correct.? Loosen the hose clip & remove the hose, then open the valve and try pushing a piece of stiff wire (or a drill bit if you have one small enough) back up through the hole in the centre. Have a container ready for when the liquid starts flowing.
Yup, that’s exactly what it looks like. Now that I have the belly pans off and more room to work I’ll take the hose off. Hopefully I can stick something up there and loosen whatever is plugging it. How essential is it that I clean the fuel inlet screen at the banjo bolt on the fuel filter housing?
A piece of 3/32" welding rod works about the best to router out the drain valve. If you have the screens in the banjo bolts, they do need to be cleaned. I've used pliers on them many times after careful locking the thing in a vise to get it out.
I agree with John. You may need to remove the filter housing from the engine and get it held in a vice in order to loosen the banjo bolt. Then reinstall the housing on the engine and when you tighten it just nip it up enough so that it does not leak. You may have to replace seals or O-rings, that’s probably why it was pulled up so tight in the first place.
Thank you! Im hoping to have more time to tackle it on Monday.
So, today was a pretty good day and I got several hours to work on the excavator. First, the good news: I was able to get the sump unplugged and drained, some nasty sediment came out but no water and it cleared up almost immediately. I also got the banjo bolt out and the screen cleaned, I was surprised how much crap was on that screen! Coolant was drained, flushed and refilled. It was pretty dirty so I was glad it was changed. Also, I swapped the hydraulic lines around to put the machine into the Deere pattern. The Cat tech line was able to send me a list of the lines to be changed. I posted photos and their diagram below in case it helps someone in the future. The colors as they are now are for the Deere pattern. If you were to match the colors back up it would be the Cat pattern
Now, the bad. First, I opened up the swing gear inspection plate and found about an inch of clear water in the gear cavity. I’m guessing it leaked in through the swivel joint boot. Any suggestions for getting the water out of there? I’m thinking a sacrificial old shop vac. Looks like I’ll need to order a new swivel joint boot too. I’m slightly annoyed because I would have thought the prepurchase inspection I paid to have completed would have caught this. Also, while crawling around looking for a drain plug for the swivel gear cavity I noted that one of the hydraulic lines under the swivel joint is kinked. I assume this goes to one of the final drive motors, what is this line for? It’s considerably smaller than the other two going to the same motor.
I assume the line with the split cover is the case drain line from that travel motor.
Also, I have a favor to ask- I’m still learning my way around SIS. Can anyone provide a part number for the swivel sealing boot? I can’t seem to find a listing for it. Thanks much!
Ok, thank you! I’ll get that one pulled out of there and a new line made.
Go to Parts->Frame & Body->Gear & Bearing Gp. Look in Group 6I-6410 Part 1 0f 2. Item 3.
Thank you!!
Working on the swivel boot today and cleaning the water and grease out of the turntable. When I started the machine today I heard a second beep after it started and noticed what appears to be the oil light is on. I shut it down and check the oil level, which was normal. Oil and filter were changed by Cat at the time of the presale service, about 1 hour ago. It’s sat most of the winter since then. I honestly don’t recall if this light was on before today, it’s cloudy today and the light is pretty dim so I may have missed it previously? No warning lights were illuminated at the presale inspection. I’ll look up this light in the manual when I get home, until then, what should be my starting point for this issue?
So, I saw that this warning light was for the oil level, not oil pressure. Since the level appears fine on the dipstick I started the engine and ran it with the light on. After a short time the light went off. So, I’ll keep an eye on the oil level and see if the light returns.
I also cleaned out the turntable cavity, and sucked out the water. It’s now been repacked with clean grease. I didn’t see any tears in the swivel joint boot but the hose clamp was loose and the seal was partially out of the groove on the swivel joint itself. There was a lot of debris packed in the top of the boot lip so I clean that out and resealed it with a snug hose clamp and a little RTV sealant. Hopefully that fixes the problem!
So the excavator repairs and maintenance were complete… or so I thought. I moved it over to my parent’s property today (there’s a trail connecting my land to theirs). While I was tracking it over there I stopped in a few places to clean up the trail and fix a few washouts. While I was using it I noted that the swing brake was acting up. When I swing the machine it operates smoothly but at times I’ll move the lever to start swinging and nothing happens. If I wait 10-30 seconds it will swing like normal. I also noticed that some of the time when it was “stuck” I could move the lever the opposite direction and it would then swing normally in both directions. Since I had to repack the swing gear cavity I know that the outer swing gear is in good condition all around. Also, when doing that maintenance I swung the house in both directions numerous times without issue. To me, it feels like the swing brake isn’t disengaging. On a couple of occasions it also felt like the swing brake would apply itself while I was working and actively swinging the machine. So, where do I go from here? S/N on first page but it’s 8GR00401, Cat 311B. Thanks!
Any thoughts on how to diagnose this swing brake issue? I’m thinking it’s electric and possibly due to the brake solenoid, so I think I’ll start there. It was also the hottest day that I’ve run the machine yet, the hydro oil was not abnormally warm though on the gauge.
Hello friend how r you everyone Anyone have full pdf for caterpillar 311b hydraulic diagram and control valve serkit full pdf thanks
Someone may have if you can supply a machine Serial Number to make sure the correct one is supplied.
8HR01417
Thanks for support