Webster Hydraulic Fan Motor

[RetDA]

(09-23-2013 14:19)cmillsap Wrote:  David, Pete,

I think we all agree that Tommy should make sure that relief/solenoid valve is working properly before trying another pump. The odds of two pumps being bad are pretty low. They have checked all the hoses and lines for blockage so unless he has some sheared metal off the shaft gear that is getting into the pump; the only other things that could cause the problem is that the flow is blocked at that filter or at the relief/solenoid valve.

Chuck

Information received from Webster today is that the new hydraulic pump failed apparently from defective internal assembly, locked up causing the torsion separation of the shaft. Subject to a "final autopsy, it appears they are going to send me a new one (Unless they want to blame it on me). John Boy Hughes at CoachCraft advises that the relief valve was tested at the last session, this past Thursday and it is in good working order. Also, using the mechanic's equivalent of a colonoscopy "snake" the power end of the DDEC II all is well and the gears are without damage.

With regards to the old Danfoss hydraulic solenoid, replacements being non existant, we will by-pass it. The fan will run at a constant 1800 RPM, which it has done anyway since I have owned the coach.

We've also removed the Parker filter. Its just somehing else in the line that BB engineered as a redundancy. The hydraulic reservoir contains three staged filters anyway.

Now, the diagnosis of the first secondary gear in OEM hydraulic pump can be attributed to improper installation. When installed, there was a 1/4 " gasket with a thick layer of black silicone that diminished the distance between the top of the gear and the pump shaft, thus seriously diminishing the amount of contact with the cylindrical secondary gear. Eventually the teeth were worn down of the first secondary gear. The old pump has been checked and is in good servicable condition, which I will keep as a spare.

New fan motor, new hoses, new fittings should put me back on the road, hopefully, I might add.

Thanks for everybody's help and advice.