Hi. I have a mustang 2042 which needed new seals in a drive motor. Replaced the seals and refitted the motor but now have no drive on that side. Did not cap the lines off and did loose quite a bit of oil while motor was out. Have filled res with new oil and replaced filters, and then pressurised reservoir to 10psi and cracked a few hoses on pump etc till oil flowed out, but still no drive. Not sure if there is some other procedure to follow. Anyone have any ideas? On the positive side my diy line boring effort worked a treat, but this hydraulic issue is driving me crazy. Many thanks Ric
Maybe Jack up the wheels and then try to drive. Get the air out of the system..?
Hi Skata, thanks for the suggestion but I have already tried that. Not keen to run the pump for extended time in case it is dry inside somehow.
Does the machine have a charge pressure light or gauge? You say it does drive the other motor though? I'm wondering if the charge pressure drops when you engage the drive on the side of your motor reseal. If the other side is driving then your charge pump should be good for that side of the loop. I hate to say it but it sounds like the drive motor is leaking the high pressure oil to case drain.
No light or gauge, but there is a test point on brake manifold for a gauge. Will organise a gauge to check (brakes release immediately though and they run off the charge pump) Not leaking into chain case (that is what started this whole thing), the case is open and chains etc removed so the motor shaft is exposed and not under load. When I say it doesnt drive I mean it doesnt move at all, and I can turn the shaft by hand which would indicate no oil in the geroller. Either I put the motor back together wrong (have just removed it again to strip and check) or there is air in the system that I cant get out. thanks for your ideas Ric
Vetech, just re read your post and now I see you mean that the oil is bypassing inside the motor and going back to resevoir via the drain line. Well the motor is out again so will check it out.
If your turning the drive motor shaft by hand then it’s way to loose. That may be the problem.
Not sure what you mean by too loose, but the shaft does not turn easily, just you can turn it, as if there is no oil in the geroller to hydrolock it if you know what i mean. Now that the motor is on the bench, there is some oil inside but it is not full and overflowing from the ports like it was when i first pulled it out.
This is why I said what I did above. Yes, I understand what your saying. If you have charge pressure, then it should be directed through the backing plate into the pistons of the hydrostat pump. The only reason I could think of at that point is the swash plate isnt being stroked to move oil. If you dont have charge pressure oil then there is no oil movement. Do you have pictures of this hydrostat pump available? Something just doesn't seem right by my understanding.
Thank you for your continued suggestions. I am researching and learning more about how this all works. Today I pulled the motor apart again to check everything is right and no contaminants etc got in there. Everything looked good, so I put it back together (thinking air in pump again) according to the Danfoss manual I downloaded. Threw it back on the machine and lo and behold now have drive - backwards !! Timed it according to the manual too, but at least it should be an easy fix - whats one more motor removal and strip between friends eh? Also put a gauge on the charge manifold and have around 150 psi which the mustang service manual says is ok Thanks again for your help - will post again tomorrow after changing timing Ric
If it's hoses, just reverse them. Hard lines, yeah, tear it back down.
That would be heaven right now but hoses are too stiff to swap. I am an expert in getting motor out now lol so shouldnt take too long.
Pulled motor again and moved “1 tooth to the left” on timing and now she is all good. Regards Ric
Yeah, timing is everything on those motors.
"1 tooth to the left." You could write the story of my life using that phrase. I'd be a rich happy man today if in my twenties I had simply paid somebody to make me do the opposite of every decision I've ever made. My daughter being the one and shining exemption to that rule, of course.