I bought a 1993 Mustang 940 from a dealer two weeks ago. He told me it was all checked out, filters changed and ready to go. I used it about 10 hours over a few days. One day I was using it and had to stop and shut down to deal with something else. I went back and started it up but it won't move or lift. I checked the oil tank and it was at what the dealer described as OK (but to me it didn't seam like enough). After fiddling a while I thought I'll add some oil, after adding a gallon I was getting worried the level in the tank was not raising up. At this point I called the dealer and he came out looked at it and said he was going back to talk with Mustang and his mechanic. He call me and said, mechanic said to fill tank to ¼ full. (now it gets really weird) 10 gallons later tank is ¼ full. (this model holds 14.5 gal.) OK now I wonder what is going on, where would 10 gallons of oil go. It wasn't in the driveway I was plowing. I looked under the seat, it had some oil(it is old) but not 10 gallons. So I called dealer again. He said that was odd, It did come with a snow blower and that would spill some oil when disconnected but not 10 gallons. OK that's here nor there, I getting off the problem I am having. I started up machine and low and behold I have Hydro power, so I raised and lower bucket and curled it like manual describes to do and cylinders cleared of air, BUT no forward or reverse drive. So finally to my question, how do I bleed the drive section to remove air?? My pump must be OK the lift works fine.
Help Support SkidSteer Forum:
walio123
Well-known member
- Joined
- Dec 9, 2013
- Messages
- 348
After you have lost so much oil and it has not leaked out, the only place where it can be is the cases of chains. Check oil level on chain cases.If you have a leaking hydromotor, the machine will either not move or will move poorly with the tires on one side. The lift and the bucket will work, the hydraulics too. Does oil continue to disappear?They receive a flow from the gear pump, and the move is from the hydrostatic pump.
No I haven't checked the chain boxes, but the oil tank is remaining 1/4 full. I do wonder if being the sump tank was nearly dry, the 7 micron charge filter might have plugged. I also noticed on the Hydro flow chart it shows something called "cold start relief @250psi", not sure what its purpose is but wonder if it could be stuck open. Its getting pretty cold out now so I will check the chain case oil level in the morning. Ya it broke down in the middle of the driveway so no way to get it in the garage.
walio123
Well-known member
- Joined
- Dec 9, 2013
- Messages
- 348
"cold start relief @ 250psi" must be a valve that, when starting a cold engine, must release the pressure in the pump to make it easier for the starter. In my opinion, it should be activated manually, but then the bucket and the boom should also not work. A clogged filter is an option, too much air in the system too, once the oil is no longer gone ... the reservoir was almost empty ...... this could poorly damage hydrostatic pumps.No I haven't checked the chain boxes, but the oil tank is remaining 1/4 full. I do wonder if being the sump tank was nearly dry, the 7 micron charge filter might have plugged. I also noticed on the Hydro flow chart it shows something called "cold start relief @250psi", not sure what its purpose is but wonder if it could be stuck open. Its getting pretty cold out now so I will check the chain case oil level in the morning. Ya it broke down in the middle of the driveway so no way to get it in the garage.
walio123
Well-known member
- Joined
- Dec 9, 2013
- Messages
- 348
This also can be a problem with a parking brake, does it work correctly?
Ya that is why I was asking if there is a way to bleed the line, thinking the line may be air bound. I guess the gear pump would force the air through to the intake of the piston pump, but I wonder if the piston pump won't push it through the Drive motors. The parking brake works good, it rolls every so slightly when I release it then stops machine when I pull it. I looked under the seat and it doesn't seam to have any lockout switch on it.
walio123
Well-known member
- Joined
- Dec 9, 2013
- Messages
- 348
It is not possible to have such an air bound in the hydrostatic system. If it's all right, it has to go., There may be some bumps initially, but in no more than a minute it will run smоot an strong.
FYI SOLVED Turns out there was water down in the pump area that froze. It froze around a hose keeping it from vibrating with the machine, hose cracked and leaked into to pan area. Dealer replaced hose and opened pan and low and behold 10 gallons of oil all over the shop. Fixed it all for free which was very kind of them. Thanks for the reply's, it helped me to investigate farther and learned a lot about the workings of the machine.
Wow, that's some awesome dealer service there!
Glad it was an easy fix.
