[Fjohnson]

Ron Skeen’s coach. Broke down because power steering stopped working.  Got off to the side of the road. Will steer when in neutral and getting rpms to 1500 but loses it again when rpms drop back to idle. Fan isn’t running either. Hydraulic pump? Thanks 

Frank

[bikestuff]

Can you check the hydraulic fluid? Open engine bay door. To the right of engine above the stainless cabinet is a square tank. Lid on top and has a gauge on right side.

Bill

[Fjohnson]

Yes, it is completely full. I’m thinking either it’s the hydraulic pump or the solenoid that’s control the valve.

[Richard]

Sounds like pump. Solenoid on fan fails to wide open as a safety.

[bikestuff]

Richard,

Ron has just had a bunch of engine work done including replacing turbo. Is there an electrical connection at pump that could have come loose which would cause the pump to stop?

Bill

[Georgeb]

My pump was leaking
Newell had one in stock
I watch the replacement there were no wires attached to pump

[Richard]

No electrical at all, mechanically driven by the engine

[bestgenman]

I remember Rahal’s coach with a Cat engine had a steering issue.  It turned out to be the pump spline and drive gear became discoupled.  I believe the spline was not engaged far enough into the drive gear to support the horsepower requirement and eventually wiped the splines off of the pump shaft.

The pump is easily removed for inspection, no hydraulic connections are disconnected.

[Fjohnson]

I didn’t realize the fan was an auxiliary fan so it did start working once the temperature increased. So the pump should be working since the fan does turn on. Spoke with a tech from Newell and he thought it may be the hydraulic cooler not working or not working properly allowing the hydraulic fluid to break down to the point that it doesn’t work as well.  Having it looked at Tuesday and once we figure it out, I will update the post. Appreciate the help and advice.

Frank

[Richard]

Frank,

That theory is out there. Let’s start simple. Standing at the open hatch, staring at the rear of the engine, you will see the lines to the pump motor going through a aluminum block at the lower left of the engine. There is an electrical connection to the solenoid on the side of the block. Unplug the connection and start the engine. The fan should come on at maximum speed. It will be a hurricane. That will tell you if the hydraulic pump is working. As stated earlier, the fail safe mode on the fan solenoid is wide open, so when you unplug the solenoid, you get max fan speed.

When you say lost power steering, can you provide more details on what is happening. Does the steering gear box make any noise at all when you turn the wheel with the engine running? What was the circumstances when the PS went away? Just looking for clues to try to help.