Cat D5M Serial # 3CR00520 Was running a bit warm. Performed the following actions: Flush radiator, clean exterior of radiator, change thermostat, check tension on fan belt. Result- operated within normal temperature range. 30 hours later: engine overheated. Shut it down. Came back later- observed small oil drips under dozer. Removed the thermostat, was enough pressure on back side (engine side) of thermostat to eject antifreeze out several feet into the air. Antifreeze was observed to be clean. Washed engine off and did not see any fresh oil. Replaced thermostat and gasket. Ran dozer at idle and mid range RPM for 30 minutes. Ran in normal temperature range. Observed no bubbles in radiator when first running. Concern: does the back pressure on the thermostat and unidentified oil leak indicate a blown head gasket? Thank you, all advice appreciated.
I'd suggest to start looking for the source of the oil leak as a first step. It ought to be visible somewhere on the engine. Was the engine stone cold at this point or still slightly warm.? Did you remove the radiator cap to release pressure from the cooling system before removing the water temperature regulator.?
Nige, Sat 7 days before working on cooling system. Radiator cap was removed prior to working on thermostat. Will resume looking for oil leak. Thanks
Located and repaired oil leak. Replaced thermostat again and drained coolant and used Cat coolant. Changed oil and filter. Dozer will run for several hours, but it starts running warm when pushing- close to overheat. Stop pushing and sit still, funning RPMs 1500 will cool down. But will quickly build heat again. Fan belt seems tight. Radiator clean inside and out. The dozer seems to get less efficient cooling the longer it is run. Any suggestions? All fluids are within specs.
Can you get hold of an infra-Red heat gun and take the following temperatures when the gauges show that the engine is close to overheating:- Radiator inlet and outlet Transmission cooler inlet & outlet (coolant side) Transmission cooler inlet & outlet (oil side)
I will do so. Thank you.
Nige, Stopped by to run dozer to keep battery charged. Noticed several new alarms. 673.02 Transmission output speed sensor 2 693.07 Speed Clutch solenoid Temperature sensor supposed to arrive today.
Sorry, infra-red heat gun to arrive today
Ended up R@R radiator - found lots of bent fins behind the fan shroud and rubber gaskets where shot. Replace sections of damaged radiator and rodded remaining and replaced gaskets. Took care of the issue. Replaced trans cooling lines/ radiator hoses while I was at it.
Colour me surprised - not.
Another thought. Did you remove and clean coolant side of the torque converter cooler core.? If not you really should have.
I was going to question your statement on ‘cleaned radiator core internally and externally’ before reading that you’ve gone back in there and sorted the issue. Externally cleaning a radiator core is a days work at least to do it properly and requires patience