I have a 1990 cat d6hxl2 with about 14k frame hours. Dozer is new to me. Rebuilt engine by a previous owner who has years experience rebuilding cat engines. New block, crank, pistons, rings, oil pump, water pump, head and turbo rebuilt. Injector tips new. Torque converter rebuilt but no previous problems. Hours on machine since rebuilt is under 200. Machine runs and operates great. Plenty of power. Air temp has been cool since I bought the dozer, but since it is warming up to the 90's I am worried about operating temp. Torque converter temp Is at the hottest after plowing hard reaches 225. Hottest I have seen water temp is about 214. Water temp drops quickly within 5 min. Of high idle to 190. TC temp is slow to drop. No warning lights but I don't want to see one either. Changed hyd. Filter, trans filter. No change. Pressure washed radiator, drained coolant, ran with simple green and distilled water for 4 hours, rinsed twice, refilled with coolant. Seemed a like it was a little longer to heat up but no real change. Belts good and tight. Changed tstat. No change. Shot water neck with temp gun and gauge seems to be close. Looks like several cores have been replaced in the past. Before I start removing cores and having them serviced, is there anything I am missing? I have not changed engine oil and filter, but that should not be an issue. Water pump was new per previous owner, and I have no reason to think it was not. Also no coolant loss or relief valve pop. No oil in water and no water in oil. Dozer does have a red dot aftermarket ac unit. Don't think the compressor is adding too much to the heat load on the machine since the temp does not drop when I turn off the ac and compressor. What is normal operating temps for this machine. I don't like seeing gauges at the end of their sweep. Still running it hard, but babying it when it gets in those upper ranges. It is only going to get hotter this summer so I am looking for any advice. Thanks.
To check your radiator efficiency I suggest shooting the temp of the bottom (outlet) water neck and post the results here. A radiator in good condition I'd expect the coolant temp to drop from 214 to 190 in a couple of minutes at High Idle no load, let alone 5.
Will do. Any idea what the temp differential should be between the exit of the radiator and the entrance? TC temp is very slow to drop. Maybe 10 minutes to get below 200.
TC oil is water-cooled so the way the temp drops will be totally dependent on the way the engine coolant temp drops. IIRC a conventional radiator should have about a 12-degree difference between inlet and outlet. I need to confirm that though.
Has anyone checked torque converter pressures? Could be plugged trans cooler or low flow.
No. Not checked. Not familiar with the procedure. Test port near the filter housing if i remember right.
Still working on the high temp problem, but i sheared the bolts on my master link on the left side. In a smoldering burn pile, no less. Loaded up the track and took it to cat. Called them before to ask if they could press a new master link on, and they said no problem. Unloaded at cat and the next day they called and said they were aftermarket rails and could not work on them. They said the rails were worn out. They could swap the rail for a cat rail for 4k plus hardware and labor. Other option was an aftermarket rail for 3k that they cant work on. Bushing look brand new, but there is a lot of slack feom side to side and a lot of wear in the pins and dry links. Picked up my track and took it to a small track shop. They actually said the rail was worn out too. They are dcm rails. Dont really know what to do except put new rails on the machine. Tracks have been riding up on the rear idler and poppinng back on since i bought the machine. I assume this is why my master sheared. I have been running them tight to try to keep it from happening , and i know that is not good. Idlers measure 7/8" from the bottom to the top on the idler in the center. I dont know the cat specs. Any ideas? My track guards are in bad shape. I had to take the removable strip off to keep the rails from rubbing constantly. I am thinking the new rails will fix my problems, but just dont know about the rails almost having no wear on the bushings. How does that happen.
Has someone done a pin and bushing turn recently? How are the sprocket segments, and the wear bars are there to keep the track lines up with the idlers, the center rib on the idler is to keep it there, most people overlook that aspect, in fact most times when we get call because someone lost or broke a track on dozer or excavator the guides (eyebrows ) look like wings, worn down and flared out. A track rail always trying to climb back on the idler wears it round and puts alot of side load on one half of the rail loosening it up.
While it's down for undercarriage I would suggest you pull the rad cores and get them cleaned and inspected. I've had a few with your symptoms and it usually comes down to the rad being plugged inside and out. The pressure washer never removes all the dirt when you wash them in the machine and you'd be surprised what gunk builds up inside the cores. If you look around you should be able to find some good used undercarriage parts. I know of a few guys around here that will just swap out undercarriage before a big job just so they won't get caught in the middle of it with track problems.
I'd second that suggestion. I was looking at a radiator the other day that had been removed from a haul truck and despite the fact that I know we do a pretty fair job of cleaning machines I was absolutely horrified at the state of the outside of the cores in the hard-to-get-at corners of the radiator assembly behind the fan guards. It was solid with caked mud TBH.
New trans filter will speed up the coolant transfer from trans much faster. Like Nige said, five mins would start the alarm bell ringing. I'd want to watch the gauge fall instantly after stopping pushing.
My guess is you need new rails.Bushing may look good ,but you have internal wear(inside the pin and bushing.They are streched out.As for the rubbing on the track guard,because of the age of your machine someone might have put heavy duty rails on your machine instead of standard rail. The boss around the pins are bigger on the heavy duty rails.Too wide for your track guards thus the rubbing! I did this on my D6H 1988 model.Got a used set of rails off a friend and they rubbed,they we so tight that machine didn't want to move.Guards had some wear so they finely loosed up and i finished wear the rail out. I had the guards moved out on the track frame to use the heavy duty rails and things have worked good since.At the time the standard tracks wasn't available.Can't remember but pad bolt holes might be different from the standard and heavy duty rails .Good luck