Komatsu dozer troubles

[Bobcatdaddy]

I’ve got a 2014 Komatsu d37ex-23. 3200 hours roughly.
When you put joystick forward it immediately turns right for a second maybe 2. After that it does great until you switch to reverse and it does the same thing. So each time you switch directions it does that. Everything else seems to be just fine. Changed hydro filters and noticed some small brass particles in it.

Sound like pump going out or something else?

 

[John C.]

The problem sounds like leakage or contamination in the joystick control valve. I haven't worked on that particular model. Does the joy stick control steering and the transmission. Perhaps a photo of the control and what it looks like inside the door on the left side might reveal what you have. Brass in the filters is usually not good but you don't have enough hours to make me think the transmission is failing. There should also be pressure taps where you can plug in gauges to see what is happening hydraulically.

 

[Bobcatdaddy]

Not sure how to upload photo from my phone. But yes left joystick steers and engages forward and reverse. Hydrostatic drive.

 

[Iworkondiggers]

Had issues with joy stick blade on the dozers getting a bit of slope causing them to do what they want and the steering ones with the springs not causing it to centre back to do things like that, more trouble than worth trying to repair them and usually doesn't work anyway.

 

[John C.]

I don't remember that those machines had hydrostatic drive. All the small Komi dozers I've worked on were conventional torque converter power shifts. They did change to a joy stick steering and transmission control. I had to reseal a D38 control some time ago. I bought the service manual in digital form and it described the process really well.

 

[Iworkondiggers]

Yeah John, the d37 -23 is a hydrostatic transmission machine, worked on a few of them, usually the pccs palm command control system leaver (steering) usually won't re-centre 100% and cause the little turn, can check positions of leaver in monitor to confirm it usually.
I don't have much experience with the old tractors , mainly the newer stuff and what not.

 

[Bobcatdaddy]

Yeah John, the d37 -23 is a hydrostatic transmission machine, worked on a few of them, usually the pccs palm command control system leaver (steering) usually won't re-centre 100% and cause the little turn, can check positions of leaver in monitor to confirm it usually.
I don't have much experience with the old tractors , mainly the newer stuff and what not.

How do you go about doing that? I haven’t figured the issue out yet. I have noticed on cooler mornings before machine is warmed all the way up that the issue is worse. Will almost turn a circle.