Caterpillar 312B 9GR00432- approximately 3900 hours on meter I do A LOT of traveling to get to the work on my farm. Recently my 312 B has begun overheating while traveling. No heat problems while working. Filters have been changed within the past couple months and hydraulic oil was replaced in 2023. As it only heats up during travel I'm not sure where to start looking.
How clean are your coolers?
Everything looks clean. Airflow thru radiators is strong. No heat problem when working, just traveling.
I need to clarify the original post. I can't EDIT the post as it's been too long. I meant to say the - HYDRAULIC OIL - is over heating. Of course the water eventually starts getting really hot also.
Next time you do some travelling try shooting some temperatures of things like travel motors, etc, at various times BEFORE the tank temp goes through the roof. It may give some cluse as to what's getting hot.
Will do. I'll check things after the Labor day holiday. I checked all the rollers, I often do. I also checked the travel motors but I don't recall what the temps on the motors was. I'll write them down this time. Any other things or areas to temp check ?? I don't run the temp into the RED. It's hard on the old girl to get her too hot. . . .
I would suggest both travel motors and maybe also the area around the centre swivel.
When we got our 312b the only seal in the swivel was the one to keep the oil from leaking externally. The rest where never installedyou could see where they should have been hitting they never where... must have been a friday. I cant speak to if it overheaded but it wouldnt hardly move one it got to operating temp. Somehow it mabaged though 7000 or so hours like that
Did some travel ling until the hydraulics got a -little- high, not -real- hot but climbing. Temperatures: . . . . in Fahrenheit Ambient=69 deg L- travel motor= 119 R- travel motor= 126 Swivel area= 120 Radiator/oil cooler bottom input ?=167 top output ?=155 Hydraulic pump head=191 output line=181 Hydraulic filter=181 If need-be I can check things again when I have to travel further and get things hotter.
If you have no info regarding when, or if, the swivel was last resealed then I would suggest you do that first.
The swivel seals were done at around 3,000 hrs-it now has 3,900 hrs on the meter. I wasn't aware that bad swivel seals could cause high oil temperature when traveling. I can check heat in more areas around the swivel if necessary.
Try lifting one side off the ground and running it to check track speed and temp on each motor. Measure the temp at the back side of the motor on the counterbalance valve .
That’s a lot of return oil for a continued amount of time. May be restricted slow return check valve or hydraulic oil cooler.
Does it have a straight travel valve?
I will try that. Do you know the speed the tracks should be running.
I don't know what valve you are talking about.
Ok it probably doesn’t have it then. There would be another pedal on the floor. Just a single pedal to the right of your travel pedals/levers.
The specifications for this machine are old school. You measure the time the machine takes to travel a certain distance on HARD level ground with the hydraulic oil at normal operating temperature. NOTE: Travel cycle time is the time it takes to travel 20 m (65 ft 7 in) after a preliminary 5 m (16 ft 5 in) run. Travel cycle time is measured at both HIGH and LOW travel speeds. Travel cycle time at HIGH speed (in seconds) ... 14.0 or less Travel cycle time at LOW speed (in seconds) ... 20.5 or less It would be interesting to note whether or not the machine tracks absolutely straight when you do this. What you can also do is mark a point on each track. Raise each side of the machine in turn and measure the time it takes to complete THREE full revolutions of the track at full speed in both slow & high speeds using that mark as a guide. Post back your results. Just to sow a seed of doubt. The fact that the swivel was resealed 900 operating hours hours ago does not completely eliminate it from the discussion.
Does not have one.
Checked forward speeds- Low L=24.08 High L=18.74 L R=20.73 H R=14.34 The 312 has always pulled to the left since I purchased it in 2013. That's the main reason I had the swivel seals replaced. But no change afterward.
From those numbers it would appear that your LH travel motor is the likely culprit. Case drain test next I would suggest. Do both sides then compare results.
Thank you for all the information. I'll check the motors. It will be some time before I can as I need to get the proper plug and tools to do the job and it is Fall 'harvest time.' Wouldn't the left travel motor show a higher heat level than indicated ?? The temp was lower than the right motor. FWIW; I have an old document written by ' someone ? ' who explains doing a 'motor check' by checking the case drain while doing the '3 revolution' track speed check. One other thing- I cannot access the "Hydraulic System Pressure - Release ." or "Operational Checks" documents.
The travel motor case drain can only be checked if the sprocket is blocked from turning. See Step 3 of the SENR9227 document. You need something like a big towbar pin to jam between the sprocket and the track chain. See attached.
Thanks once again for the documents. I finally figured out my Cat access problem. I will follow your posted instructions. I only put the FWIW in there to show the useless misinformation some people put out as fact. Not important but to me it seems counter intuitive that the higher hot oil flow thru the left motor would show up as a lower temperature than the right motor.
Your thinking is logical but consider the possibility where elevated friction as a result of wear could possibly create a much higher level of heat generation in the worn LH travel motor.
I like to stall the sprocket against the roller frame rather than the chain. Sometimes the track link condition is pretty poor and I’m worried about breaking track links. I use a chunk of solid round stock with a flat cut in it, flat goes against the roller frame.
Good point. The left motor has always been pretty weak. I have considered replacing it several times before but it's always worked -good enough to get the job done.- That reason and in anticipation of the likely inevitable I'll probably start figuring out the correct part number and begin lining up some potential places to purchase a replacement motor.
That should work well. I previously jammed a solid heavy bar in the sprocket/frame while checking the swivel. I didn't trust jamming the track.