I've just started using a Fecon mulching head on my Cat 299D2 XHP and the hydraulic temp seems to be exceeding 180 degrees F withing 15 minutes. Before adding an external oil cooler, I was trying to verify that the hydraulic cooling system was working as it should. There is a valve just before the hi-flow auxiliary return line attaches to the main control valve that allows oil to pass to the oil cooler. It joins with the case drain return line and goes into the cooler input. After my hydraulic oil temp gauge reaches about 190 degrees, I am checking the temp of the line that goes to the cooler from the return line, and it is only reaching 130 degrees. This seems too low for there to be flow going to the cooler, but I don't understand why it is as high as 130 if the valve is not opening to pass any oil. I was wondering if it is just reaching 130 because it is a metal pipe that is connected to the cooler. Anyway, I replaced the solenoid on the valve that connects the cooler line to the main high flow return line and this made no difference. Still about 130 degrees going to the cooler, even though the main return line is about 175 degrees. Should I assume that this means that the actual valve passing oil from the return to the cooler is stuck closed? Should I try replacing the valve instead of just the solenoid on the valve? The serial number of the machine is DX200548.
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Cat 299D2 XHP hydraulics overheating
- Thread starter mjones35
- Start date
Simon C
Senior Member
- Joined
- Jul 1, 2015
- Messages
- 698
- Location
- Rocky Mountain House , AB., Canada
- Occupation
- Heavy Equipment Mechanic
If you look at the bottom and top of your radiator, is there any sections that are matted with dirt. Have seen a lot of cat radiator style skidsteers with rads that were 50% plugged when looked at carefullly.
Just for your info. have seen many a machine underground that the hydraulic oil was over 220F for most of the day. It is hard on hoses and seals at these kinds of temperatures but some machines can stand elevated temps. for quite a while. I am assuming that you have actually checked your radiator to make sure that it is full to the top with the rad cap off and not just looking at a sight glass. Hopefully you have the right viscosity of oil for a mulcher that will make your hydraulic system work to max. Hope you find the problem.
Simon C
Just for your info. have seen many a machine underground that the hydraulic oil was over 220F for most of the day. It is hard on hoses and seals at these kinds of temperatures but some machines can stand elevated temps. for quite a while. I am assuming that you have actually checked your radiator to make sure that it is full to the top with the rad cap off and not just looking at a sight glass. Hopefully you have the right viscosity of oil for a mulcher that will make your hydraulic system work to max. Hope you find the problem.
Simon C
Nige
Senior Member
Do you have the Monitor Panel that allows you to pull up Diagnostic Codes.?
If you do, have you looked for any Codes.?
If not, is the "Operator Alert" warning (exclamation point) illuminated solid or flashing.?
If you do, have you looked for any Codes.?
If not, is the "Operator Alert" warning (exclamation point) illuminated solid or flashing.?
Nige
Senior Member
What was the Part Number of the replacement solenoid that you installed.?
The part number of the solenoid that I replaced is 421-5476. Looking at the parts manual, the actual valve is part number 421-5423. I'm having a hard time determining if the valve part number includes the solenoid. I assume it doesn't.
I was about to disconnect the electrical connection from the solenoid and test to see if this has any effect on the cooling. The schematic that you sent seems to confirm that this valve does in fact control the flow of oil from the high flow return line to the cooler. If the line to the cooler is still at about 130 degrees when the main return line is near 180, that would seem to tell me that the 130 degrees is just from the conduction of heat from being attached to the radiator. That's assuming the valve would normally be closed when the solenoid is not powered. Do you know if this is the case? I would just unhook the line to test, but I don't have a plug for the female end.
I will check on that this afternoon. The built-in panel allows me to view any codes.
Thanks for the suggestions. I looked at the bottom and top of the radiator and it looks clean and is full. I may well have an unrealistic expectation for the max hydraulic temp I should be reaching, but just want to make sure everything is working properly before getting near the temp that triggers any warnings or shutdowns, which I believe is only a little over 220F.
Just wanted to mention that the reason that I became focused on this solenoid/valve was because I was looking at the details of the CAT auxiliary cooler that can be added to this machine, and this is where the input line connects to that auxiliary cooler, just after this valve. You are then supposed to cap the line that the valve was formerly attached to and then run the output from the auxiliary cooler back to the hydraulic tank. If I do add an auxiliary cooler, I was just planning to instead run the output of the auxiliary cooler back to the line that goes to the main cooler so that both are used.
Nige
Senior Member
That 421-5423 valve definitely has to be powered to open. Have you tried removing it and opening it up to see whether or the spool/slug/whatever is free to move.? Or even remove it and power up the solenoid with external 12v and see if the valve opens.?
Also 421-5423 Valve does include the 421-5476 Solenoid. The solenoid is the only part of the Valve Assembly that is serviceable as a spare part.
Also 421-5423 Valve does include the 421-5476 Solenoid. The solenoid is the only part of the Valve Assembly that is serviceable as a spare part.
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This afternoon I unplugged the power connector from the solenoid and ran the mulcher until the hydraulic temp got to about 190F. Didn't seem to heat up much faster, maybe a little. The interesting thing is that I immediately checked the temp of the metal line going from the valve to the cooler and it was now only about 98F. It was 130F before. Does this mean the valve was working? Could it be possible that the valve is only opening slightly? I'll look at removing the valve and solenoid and checking it with external 12V. Might be beyond my technical ability to determine if it's opening fully. Part 421-5423 is listed on Cart Parts Online for $286.66.
The cooler is over 170F, but I guess this heat could be coming mostly from the engine coolant portion of the radiator.
Nige
Senior Member
I wouldn't consider replacing the complete valve unless the old one had been tested and found to be defective.
Have you checked to see if the solenoid is getting 12v when you power up the Aux/high Flow hydraulics.?
If it is then I'd suggest removing the valve and trying to blow through it when the solenoid is powered up.
Have you checked to see if the solenoid is getting 12v when you power up the Aux/high Flow hydraulics.?
If it is then I'd suggest removing the valve and trying to blow through it when the solenoid is powered up.
Thanks. I agree that replacing the valve should only be considered if the old one is definitely defective. I'll see if I can get it off and test it. Even adding an auxiliary cooler doesn't make sense unless I can verify that this valve is working properly since the input to the cooler would be connected to the output from this valve.
Joe Zhao
Well-Known Member
I bought a Cat 299D2 XHP used several months ago. It is a 2018 build with about 1400 hours on it. I am just starting to use it now with a Loftness Forestry Mulcher, to clear some light brush. I see both Coolant and Hydraulic temperature indicator keep rising while operatin. After about 2 hours of use, the coolant reaches about 212F and the hydraulic reaches 194F, but not reached to the rad zone yet, and no warn sign or alarm. But I think it’s better to stop and let it cool down before continuing use it. The July weather in Texas is hot, but it was in the morning, ambient temperature was about 85F.
is this considered normal or considered as overheating?
is this considered normal or considered as overheating?
Nige
Senior Member
Have you checked the condition of the radiator & the hyd oil cooler.? Working in dusty conditions they can get plugged really easily.
AFAIK the high temp alarms for the coolant should go off at about 230F and for hydraulic at about 210F, so you are still a way away from alarm.
AFAIK the high temp alarms for the coolant should go off at about 230F and for hydraulic at about 210F, so you are still a way away from alarm.
Joe Zhao
Well-Known Member
Just checked the ratiator and hyd oil cooler, they all appears fine to me.
Please take a look photos below taken this morning, do they look good to you as well?
Engine radiator:
Hydraulic cooler:
3) Air condition radiator
Temperature readings starting the engine in the morning:
Nige
Senior Member
Where the trash gets trapped is in between the oil cooler and the radiator which requires disassembly to clean it. With the strands of grass visible in your photo I’d still suggest to pressure wash both of them if you had them apart.