Any suggestions on what could be the problem-- 98 D5C hystat dozer 3046T engine- just replaced the water pump, thermostat, rad hoses, pulled and flushed radiator, new temp gauge and new temp sender- all factory parts- shows to be running hot at near 240-250- the upper hose gets hot, but the lower radiator hose stays COLD ! - I pulled the upper hose while running to confirm that coolant is exiting and returning to the upper hose connection on the radiator, so coolant is flowing. Something is wrong somewhere- how can the lower hose be cold?
You did all the work listed above why exactly..? Was the machine running hot and you were trying to fix it or were you overhauling the machine/replacing components and the overheating developed after you started the machine up again..? The fact the lower hose is cold suggests that either your radiator is plugged internally or for some reason the water pump is not circulating coolant. By the sounds of your post you have confirmed that coolant is flowing out of the thermostat housing (or at least it sounds like that to me - please confirm). I suggest the next step would be to pull the hoses from both the top and the bottom of the radiator and pour a bucketful of water into the top hose as fast as it will go. Does it fall out of the bottom hose connection or does the radiator tend to fill up with water..?
Have you shot it with a temp gun to verify the gauge readings
Yes the machine was running hot and we decided to try and fix this problem- very frustrating- we bought the dozer and were unaware of the hot condition - the temp gauge and temp sender were both broken. ( probably on purpose to disguise the problem) We bought the dozer just recently from a so called reputable dealer here in Texas and we believe that they failed to disclose the problems- the dealer will go un named , but we are trying to fix the problems. My other recent posts are about the failed gasket at the rear of the engine block causing a bad oil leak- we are trying to resolve the cooling problem first, before pulling the engine to fix the rear oil leak. ( (so you are probably wondering why we didn't see the bad oil leak?- the belly pan was so full of sand and dirt that it acted as a "sponge" and we just didn't see the dripping at the time of sale- the dealer claimed that the oil leak was from the oil cooler and replaced that component at huge expense to us- only that was NOT the source of the oil leak) Needless to say we are very displeased with having to make these repairs on what otherwise "Looks" like a great dozer from appearances.
Make sure you have the correct temp regulator. It might control the bypass and not be doing that. Later Bob
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