Cat D3C II won't steer properly to one side

[Kyle Carson]

I'm working on a D3C series II, 4HJ, that doesn't want to steer to one side. The left pedal will work perfectly...clutch disengages and the brake works smooth and easy for a left turn.
The right pedal is much harder to depress and when it is fully applied the machine comes to a stop. If more throttle is applied, say 50%, then it will go ahead and turn right. I have checked the slave cyl pressure on both sides and they are both the same, 360psi. I don't understand why the left track will not push the machine to right until it gets more fuel, and the fact that it will go ahead and work tells me that the left clutch is still in working order. Thanks for looking at this, any help is appreciated.

 

[Welder Dave]

The rollers on the steering clutch valves under the seat could have flat spots on them not allowing the clutch to release. Look under the search feature on here. 931B and D3B are very similar.

 

[Kyle Carson]

Thank you for your reply.
No flat spot issues on the rollers but I did find something that is puzzling.
When I step on either pedal I get 360psi to the slave cyl. but if I step on the other side at the same time then that 360 goes to 0 and reengages the clutch. This happens on both sides, 360 to 0. So, if I'm in first and step on both pedals together then I'm fighting the engine because one clutch is engaged. It seems to me that when you step on both sides together that both clutches should be disengaged and the engine should not be under much load since it is only turning the transmission and bevel gear.
If I'm making a mistake in my thinking then please help me see the errors in my thinking.
thanks
K

 

[Welder Dave]

If you push both half way down, you should come to stop.

 

[Kyle Carson]

yes I agree but when I push one side down 360psi, then push the other half way down it goes to 0. I've seen a lot of things but never that.
I can't figure it out, and since it does it on both sides, I'm double confused

 

[Vetech63]

There is a leak in the steering pressure system.........looks like the right side.

 

[Kyle Carson]

So I guess I need to pull the valve and rebuild it..should be pretty simple

 

[Vetech63]

So I guess I need to pull the valve and rebuild it..should be pretty simple

It may or may not be the valve. It could be the steering piston seal for that right side. You should do some pressure tests for the right side before yanking anything apart.

 

[Kyle Carson]

I've tested the slave cyl. port from the outside of the machine. Where else should I check? I've not had too much trouble out of these before and any help is appreciated
K

 

[Welder Dave]

The valves under the seat may need to be rebuilt.