4104 power steering

[Harry6674]

I have a 4104 with the original power steering that isn't working right or maybe not at all. I bought the bus 4 years and been redoing the interior ever since. I drove it home about 150 miles with the steering getting progressively worse. Checked the fluid level and it was dry. Added 4quarts and started it with oil gushing out of the slave cylinder seal. Replaced the seal but am afraid either the pump or cylinder got damaged. In the manual it says it has like 950# pressure relief valve. Is this the pressure I should see when I start the bus? Any help?

[chessie4905]

   There should be a bleeding procedure when the system is mostly dry and refilled.

[Harry6674]

Yes I went through the bleeding procedure according to the manual.

[gus]

Yes. Maybe not all the way to 950 on such an old bus, but close.

The pump runs all the time. It is a vane type pump and the vanes can easily be damaged when run dry.

The good part of this system is with no power assist you still have normal manual steering. To Sheppard can make that statement!! You only have manual steering anyway going down a straight road.

[Harry6674]

Thanks Gus. I'll hook up a gauge today and see what it says.

[digesterman]

You can open up the pump and inspect it for damage to the vanes, on most vane pumps you can flip each vane, just make sure you put everything back in the same order that you took it apart. Some have little springs under the vanes, others have something like a leaf spring (this is vane pumps in general).  If the housing is scored then you need to replace pump, rebuilding doesn't pay normally, parts cost as much as new unit.

Good luck, hydraulics are really not that complicated.

[Harry6674]

I've got something weird going on. I hooked up a pressure gauge to a T on the pump pressure outlet. The pressure was barely registering. I started to remove the dipstick to check and it had a lot of pressure behind it. That was with the engine at idle. That doesn't seem normal does it?

[luvrbus]

Your system is air locked

good luck

[digesterman]

Your system is air locked

good luck

luvrbus is probably dead on here. Air is compressible, it will cause you all sorts of problems when trapped in the wrong place, try loosening a fitting on the out side (pressure) side of your pump, hopefully any air trapped will be pushed out. When all the air has been evacuated your system SHOULD be back to normal. As luvrbus said, good luck.

[gus]

luv is right, you didn't do the bleed procedure in the book long enough. It takes quite a few times back and forth with the front end off the ground.

[Harry6674]

Thanks for the help. With your advice and Luke's shop foremans help I hope I've got it bled. Now my issue is with the wheels off the ground it wants to creep right so I will try that adjustment tomorrow. Thanks again.