I was running the dozer last weekend, knocking down some dead trees and grading a creek crossing to keep overflow off of my fencelines. Probably the most time I've spent on it since purchase.... Anyway, I was walking it back to the barn and intermittently, the steering clutches wouldn't release. Pulling back on the steering levers (left or right) would simply bog or kill the engine. I could stop, back up a little and actuate the clutches/brakes and everything would be OK for a while. I need to pull the floor plate and check linkages but meanwhile I thought I ask the experts for an opinion. Input anyone?
BTT. I've been swamped with other work and haven't even taken a look at this yet. Thought I'd bump it back to the first page on the off chance someone might have some input. In other news, Dad was running the dozer today (first time to be used in a month or so) and had to add a gallon of oil to the main clutch case. Last time I ran it I had to add about the same amount...it isn't leaving a puddle underneath either. Where is it going?
OK, so now I've spent some time with the shop manual and, from what I can tell, the failure of the steering clutches to release is most likely coupled with the loss of main clutch case oil. Low oil there could prevent the steering valves functioning and disengaging the steering clutches. I need to find out where that oil is going.
I have the D21 P-6 with the powershift. Sorry I can't help you with the clutch question. Maybe the manuals will help.....I know I can be traveling in a straight line and pull gently back on the steering levers at the same time and machine will stop. Further back are the brakes...same as yours, I guess. Machine will run pretty straight with one clutch disengaged. Good luck Pete in MS
I need to find out where that oil is going. Most likely the fluid is leaking into the final drives. Check the final drives and you'll probly find that they're over full. There's seals btween the clutch housings and the finals if I'm correct it will soon be leaking around the drive sprocket/s. BTW you are right in thinking that low fluid levels will cause your problem.
Eureka! I pulled the floor plate last night and discovered a leak in one of the flexible hydraulic lines going to the oil cooler loop. The oil that was initally coming from the leak was getting soaked up by the accumulation of dirt and leaves inside the skid pan. Getting the lines loose for, what I'm guessing is, the first time on this 17 year old machine was no small task. Additionally, there's ZERO room to get a wrench onto one of the fittings, much less a wrench with a cheater on it. Eventually, I pulled the flanged metal lines off the clutch housing and dragged the entire assembly, flanged metal lines along with the hoses, out into the light of day where I could attack it with room to spare. Turns out that the NAPA that's nearest to the farm has the ability to not only make hydraulic hoses but hoses with METRIC fittings!!!! A trip into town and $145 later I walked out of NAPA with a new set of hoses, oil for the main clutch plus some other trinkets I needed. I've pulled service on major appliances, cars, boats and my tractor but a dozer is a first for me. I'll head back out tomorrow to reassemble the beast and see what happens. Neato. Thanks for the pointer Bender! I looked at the manual closely and on this unit, I don't see anyplace where the steering circuit oil could make it into the final drives or clutches. I'm pretty sure the steering clutches are dry clutches too so, if oils did get in there, it would be a disaster...and, immediately noticed!
Congratulations R Leo You are a good mechanic and I have filed your problem away in my Dozer section for the future....I could have that same problem with my hydro drive system. Pete D21P-6
Reassembled it all today and, it works like a champ...took the time to do some other maintenance as well. The belly pan had a rusted out place so I welded in a patch to prevent a stick-up from poking through. Also adjusted the steering brakes (the left one wasn't hooking up all the time) and, I started replacing the implement of torture that Komatsu calls a seat. Someone else's post showed an automobile seat in their D20. I thought that was a good idea so I pulled a front seat out of a 1980 Mercedes parts car that I have and started fabricating a mounting plate for it. I did take the dozer for a quick spin with the seat in place and I have to say that a seat with springs is a substantial improvement over a 3" foam cushion. It will be about two weeks before I can get back to the farm and do any more work on it...I'll take some photos and post them when I do go back.
AFIK, the hydro's steering is the same as the manual's. Looking back, I think the hardest thing was getting the belly pan reinstalled.