How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask catguru8201 Your Own Question
catguru8201
catguru8201, Technician
Category: Heavy Equipment
Satisfied Customers: 93
Experience:  7 years of troubleshooting many different Caterpillar equipment models. If you need to know something about a CAT, just ask me!
62274170
Type Your Heavy Equipment Question Here...
catguru8201 is online now
A new question is answered every 9 seconds

Skid steer..loader..reverse and it releases but going..locking

This answer was rated:

Have a2005 caterpillar 247b skid steer loader. After about 15 mins use left track (track motor) locks up. I can go in reverse and it releases but going forward again it starts locking up again. If I rin the machine at full speed I can usually get it to work

olehaggard :

sound like a regulator

olehaggard :

needs to be adjusted

olehaggard :

to allow more fluid to flow faster

Customer : How do I do that and where is this regulator located
olehaggard :

i would follow line off pump or check around pump im not sure on this peticular model

Customer : This is not the kind of help I was expecting. I need an expert that knows the detail about this machine
Customer : This not the kind of help I was expecting. I need an expert who can tell me how to fix this problem. Tks

I'll try to help with this one.

 

I would suspect that you have a resolver ball leaking in the pilot joystick. You should get pilot pressure to the pump swashplate from the joystick when the lever is moved to the forward position.

 

 

It is port D on the joystick and port X4 on the front pump. The port is on the pump closest to the engine on the left side. It will be a small line going into the swashplate servo or actuator.

 

For the motor to lock up only in the forward direction and not the reverse direction, I would say it is in the joystick since the swashplate will move in both directions and the track does not turn without a command like if the swashplate actuator was getting stuck or the seals were blown.

 

Since it works in reverse and for the other track in both directions, pilot pressure is ok in the system. If the brake in the motor were locking up the direction shouldn't matter and both motors should do it because the parking brake oil splits after the solenoid and goes to both motors.

 

The swashplate is spring centered and when pilot pressure is low enough, it will center up and lock the motor hydrostatically.

 

I will not be near a computer for most of the day tomorrow. I would suggest that you install a pressure gauge on port D at the pilot joystick and see what happens. If you don't have a guage, you could also swap lines C (right forward) and D (left forward). This should make the right track lock up in forward if the issue is in the resolver block on the bottom of the pilot control joystick. The right side uses a different resolver ball, and it is working since it has no issues on that side.

That is the left side when looking towards the pumps from the front of the machine, not in the seat. Here look at this view of the pump.

 

http://dl.dropbox.com/u/52086793/pump.jpg

 

 

catguru8201, Technician
Category: Heavy Equipment
Satisfied Customers: 93
Experience: 7 years of troubleshooting many different Caterpillar equipment models. If you need to know something about a CAT, just ask me!
catguru8201 and other Heavy Equipment Specialists are ready to help you
Customer: replied 5 years ago.
Do u have diagram of joystick hydraulic line hook ups
Let me see...however the ports should be labeled on the bottom of the joystick I believe

This isn't the best picture but it is all I can find.

 

http://dl.dropbox.com/u/52086793/pilot%20lines.jpg

 

Just locate the hose labeled 5 back at the joystick...or you could swap at the pump. The forward ports are on the same side. So you could swap lines there if needed

Customer: replied 5 years ago.
Ok thanks so much u have been very helpful. I buy lots of cat skid steers don't have much problems but when I get one it's wooley boger
Let me know how it went.