772CH front wheels acting like brake dragging in reverse

[terex herder]

SN 570602. In reverse the front wheels want to skid sometimes. When trying to turn in reverse the wheels plow some, acts like diff lock in engaged. It seems like this happened last week after we changed a leaking hose for the left front wheel. After a couple of hours of work today the front hubs were 140F+, hydraulic oil just 90F, also kinda like brakes dragging. Will get a charge pump pressure loss when shifting into reverse, then goes away.

Any suggestions where to look?

 

[mg2361]

Any codes?

 

[terex herder]

F213 shows up now. I don't know if there are more, as select soft key on dash doesn't work.

Brake (or whatever is causing drag) is really only in reverse. Grader coasts easily when in neutral going forward, stops very quickly in reverse.

 

[mg2361]

F213 shows up now.

Aggressive switch has no power. Check Fuse F36.

I do not work on too many motor graders, so I am not sure if that code would affect it or not. It is a shame the select button is not working. Losing charge pressure at engagement would lead you to believe there is leakage somewhere. Do you know which circuit that hose was for? Hose part number?

Do the wheels turn OK if the HFWD is turned off?

This is where you really need the tech manual TM1606.

 

[terex herder]

Fuse is good. Wheels skid when fronts turned off. I will have to check if they skid when turned on. I have the TM on the way. A TM came with the machine, but it is for a series 2.

What is the aggressive switch?

 

[mg2361]

What is the aggressive switch?

 

[terex herder]

Thanks, will check out the wiring.

 

[terex herder]

OK, have the TM. F36 ( and all other) fuses are good. The aggressive switch does have power, and by ohming the wires the switch appears to work.

Do you know if there was PIP on K19 hfwd forward solenoid relay? The relay is gone and has a wiring harness in its place that runs to a small box that says it is a 1.5 second time delay.

 

[Cliffy]

Wonder if hose brade or something has jammed the spool valve. Was the new hose flushed out?

 

[mg2361]

Do you know if there was PIP on K19 hfwd forward solenoid relay?

None found.

Did this unit work fine before the hose replacement?