Need help trouble shooting my skidsteer left track will not move forward or backwards? Any suggestion would help. The bucket and boom hydraulics are working and so is the other track. Thier are two big hydraulic hoses which I assume are the forward and reverse siurce for the drive. What do the two small one do? My skidsteer has highflow and and turbo if this makes a difference.
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CAT 287B Skidsteer Hydraulic Problem
- Thread starter bmanlyo
- Start date
mikebramel
Senior Member
When you comman the defective trackmotor do either of the hoses kink or jerk as if they are under pressure?
If the hoses to the motor react to pressure, it means the valving is OK and eliminates that as a problem. It could mean there is a problem in the motor or the track is jammed somewhere mechanically
mikebramel
Senior Member
Yes, if the hoses kink the pump is meeting resistance. That would mean the pump is atleast good enough to turn the track. Most likely the motor would not have a failure that would jam it up and you have a problem inside of the planetary box. The other two lines are your motor drain and either two speed or brake line. Drain lines should not have any pressure. Motor lines 3500 or so. Two speed line 250-500
Nige
Senior Member
As you have rightly said the 2 large hoses are for forward and reverse motion. If you put the machine in forward or reverse then one or other of those hoses (depending on which direction you are trying to move) should tense up like an iron bar.
One of your smaller hoses will be the case drain line for the hydraulic drive motor, the other one provides the hydraulic pressure to release the internal parking brake in the motor that is spring-applied. When you try to move the left track one or other of those small hoses should give signs that it has pressure in it. When you move the direction control back to neutral the pressure should release.
Yes I was going to do that but I read thier could be contaimanent in the closed loop which could cause problems in the working drive, what's your thoughts on that?
oldtom
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- Australia
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yes there could be contamins in the line , remove hose and using a clean white lint free rag pall thought with a length of wire and check, the oil for all circuit end up in the hydraulic tank if the seal to the brake piston are leaking the motor will not drive but load up that motor check case drain for exes/flow you could remove that motor and jack up and try to move drive though
Its jack up off thw ground, if its the brake what do I need to do to release the brake so the drive can move by hand, if the brake is the problem would thev track rotate if I pull the skidsteer with my tractor, or what if the drain hose is clog up would that affect the drive
Nige
Senior Member
As per my suggestion in a post further up, did you try to drive the machine and look for signs of pressure in the 2 large hoses..? If the machine is jacked up off the ground that's even better and I suggest that if you have not done that yet do it before going any further.
Let's explain the "drain line" a bit first. Your drive motor is a hydraulic piston type and all motors of this type by design leak internally by a small amount. The "case drain" line is to take this leaked oil from inside the motor case back to the hydraulic tank.. It is very unlikely that the case drain line could get blocked, but it is a remote possibility. So if you remove the 2 small lines at the motor end and try to blow through them you should be able to blow through one and not the other. You should hear bubbling in the hydraulic tank when you do this. Try leaving that hose disconnected, start the machine and try to move it. See how much oil comes out of the connection on the motor. It should be a steady trickle, but if it's a flood then your travel motor has a major internal leak and is most likely goosed.
Having identified which is the case drain line by a process of elimination you know which line is the brake release. Re-connect the hose, start the machine and try to drive that track while someone watches (or holds) that hose close by the travel motor. It should be possible to see/feel it "pulse" with the pressure in it when the travel control is moved. That's is the pressure that is releasing the brake and is as near as you can get to see whether the brake is releasing or not. If you have something like a Porta-power pump maybe you could rig that up on the brake line and release the brakes manually.
NOTE: For every line you remove check carefully for signs of metal particles both in the line itself and also in the connector on the motor. The presence of lumps of metal could also be an indication of problems inside the motor.
Let's explain the "drain line" a bit first. Your drive motor is a hydraulic piston type and all motors of this type by design leak internally by a small amount. The "case drain" line is to take this leaked oil from inside the motor case back to the hydraulic tank.. It is very unlikely that the case drain line could get blocked, but it is a remote possibility. So if you remove the 2 small lines at the motor end and try to blow through them you should be able to blow through one and not the other. You should hear bubbling in the hydraulic tank when you do this. Try leaving that hose disconnected, start the machine and try to move it. See how much oil comes out of the connection on the motor. It should be a steady trickle, but if it's a flood then your travel motor has a major internal leak and is most likely goosed.
Having identified which is the case drain line by a process of elimination you know which line is the brake release. Re-connect the hose, start the machine and try to drive that track while someone watches (or holds) that hose close by the travel motor. It should be possible to see/feel it "pulse" with the pressure in it when the travel control is moved. That's is the pressure that is releasing the brake and is as near as you can get to see whether the brake is releasing or not. If you have something like a Porta-power pump maybe you could rig that up on the brake line and release the brakes manually.
NOTE: For every line you remove check carefully for signs of metal particles both in the line itself and also in the connector on the motor. The presence of lumps of metal could also be an indication of problems inside the motor.
Raised it off the ground and check the lines on both side, niether side kinked or jerk but I could feel vibration as if thier was hydraulic flow moving through the left and right drive motors, what activates the brake and if its in the brake position it would look up the drive motor, so is the hydraulic fluid bypass the gears in the drive or does the brake just block the hydraulic fluid? Should I be able to spin the drive by hand if the brake is released in the drive? Thanks
kshansen
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I could send you a 8 page file that shows the drive motors and brake that identifies the ports and explains a lot about them.
I would need a direct email address as the file is too big to post here.
email me at
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Thanks, here's my email:
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Guys, send your addresses to each other by PM. When you publish your address on the internet like you did here, you expose yourself to harvesters and will be slammed with spam. I removed them for your safety.