I’ve got a komatsu d37e-2 dozer that I have been waking from the dead.I was having difficulty with the clutches releasing and hesitation changing gears so I check the trans pump pressure.It was about 120-130 and it’s supposed to be around 300 so I changed the trans pump with a aftermarket pump from Kent Baugh equipment. So after I reassembled everything,I have zero pump pressure.I thought it just wasn’t primed so I attempted to force some oil in through the steering line that comes outa the modulating valve but didn’t get much in.I then cranked the engine and would get squirts of oil but nothing near like I would expect,it may just be the stuff I tried to squirt in,idk. I’ve removed and reinstalled the old pump twice (long story)and never had an issue with priming but just figured since this is new it didn’t have the residual oil to create pressure.I still think it may a priming issue but unsure of how to go about it.Is it a possibility of a bad pump?I did clean the strainer before reinstalling so it should be working This thing has been a major headache and I’ve got way way more money in it than it’s worth but I just want it to at least work for me:/Any help is greatly appreciated
Anybody?
Those should be gear pumps and priming shouldn't be an issue at all. They need a little oil dropped in the outlet before start up for lubrication but other than that they should pick up right away. I don't recall if that machine has a canister that the strainer sits in or the strainer is in the suction of the main case. Did you replace any O rings that might be in there. What about suction hoses?
Strainer is in the transmission(bottom right corner.Than there’s a 6” hard pipe with o-rings from the strainer cap to the pump.As far as I know those o-rings looked good but I didn’t check that for suction leak yet. Before when I ran it,if it wouldnt turn,I would push in the inching pedal than when I would release it again it would turn every time.So that got me thinking,The back pressure from that inching pedal was pushing some for valve closed(Modulating relief valve?)and it would work for a bit.Oil goes through the modulating valve,through the gear selector,through the inching pedal piston,than into the f/r selector.As far as I can tell from studying my manual,when the inching pedal is pushed,it just stops the flow from going into the f/r spool and maybe that back pressure was enough to push a sticking modulating valve closed so pressure could build instead of just allowing it to go straight to oil cooler. You can tell I’m grasping at straws lol.It could be leaking piston seals in the transmission but that’s unlikely considering it does it in all the gears Yes it’s a gear pump and I don’t think priming is an issue anymore because I took off the steering line and oil was shooting out at just cranking speed.I tried to check the steering pressure but of course it was nothing as well because oil will follow the path of least resistance(I’m thinking sticking valve here).Sorry for the tremendously long posts but I’m at my wits end with this thing
Does your machine have joy stick steering?
Nope,All manual The weirdest thing for me is that I had some pressure with the old pump but none with the new one.But there’s all most no way you can mess up installation
Was the new pump an aftermarket unit? Could you take a photo of the new pump that you got and post it here?
Yes it was aftermarket.I can get a pic tomorrow but it looked pretty much like the old one except no paint and rougher outside finish.I’m not crazy over aftermarket but komatsu wanted like 1800 or something with no ship date available.This one was 550
Ok so this is very embarrassing but….I had the transmission strainer in backwards.Lol It definitely shifts better with no hesitation but it still won’t release both clutches at the same time.It releases 1 at a time if your not pushing the other pedal at all but refuses to release both.I don’t guess the oil I used is hindering me?It was pure guard 30 weight and it’s very heavy and seems sticky so it could be making it hard to release.Idk
I'm not sure I understand what you are saying. Are you talking about two transmission clutches or both steering clutches? Power shift transmissions always have one clutch engaged. Why would you wish to release both steering clutches?
Well it’s my understanding that when both pedals are pressed,both clutches should release.Is this not correct?
Why would you pull both steering clutches?
They are on pedals with the brakes so it would be nice sometimes because since your feet are on there anyways,You can stop quickly.You can definitely run it without but it just bothers me because it doesn’t work
It isn't recommended to run the machine with your feet always on the brakes. Do you have an operation and maintenance manual? As I recall there is a priority valve that routes oil between the steering and braking systems and then onto the transmission. What that valve does is ensure there is enough oil for steering and brakes before the transmission can go into gear. On the older dozers steering oil was shifted to a steering clutch until it was released. Which ever clutch was actuated first got all the oil until the clutch was fully released and then oil could go to the other one. It sounds like your machine has pedal steering. Do you have three pedals or just two and do you have a decal pedal?
Thanks a lot for your help! This is my first time running a dozer and it wasn’t running when I got it so I’m not exactly sure what to base everything on.It has 3 pedals,2 clutch/brake combo,and a inching pedal.Also it does have a decel pedal. When I push a clutch pedal,the pressure drops just a bit than climbs again so there is pressure there to release both I should think Also,as far as I can see,there is no priority valve.The the steering circuit oil is first inline(before transmission). As far as operating it,it’s no problem for me the way it is but when I go to sell it,I’d like to have it right.
It is the way it is supposed to work.