Power Steering fluid out the breather tube

[kiss6669]

Drove my rig to fill up with gas. Started rig and I had no power steering. As I was driving back home the power steering would work then not work, brakes had limited function also. Stopped at home to check things out and power steering fluid was coming out of the breather tube on the top of the reservoir onto the ground. It stopped after a few seconds but any time I drove for a bit and stopped the fluid would come out the tube again.

I replaced the power steering pump thinking it was bad due to the whining sound it was making when driving and putting on the brakes. Same thing is happening with the new pump, not as much whining except my me now.

1994 Fleetwood Pace Arrow
P30 Chassis, 454 motor

Thanks for any suggestions or help.

 

[John From Detroit]

Sounds like you have a fairly large air bubble in the system (Power steering also powers brakes) as the air expands due to heat .. Well, you  described what is happening.

But frankly. I do not know how that could have happened.

 

[Gary RV_Wizard]

I would guess some sort of blockage in the hydraulic lines. The pump is pumping but the fluid is unable to move as it should, so pressure builds and it backs up and out. Could be hoses, or the valves in the power steering unit itself. An air bubble could do it, but so can kinked lines or stuck valves.

 

[kiss6669]

I plan on checking the lines and the reservoir tonight. I read that the reservoir screen at the bottom can get gummed up and blocked. The new pump that I installed resulted in the same backflow problem.

 

[2kGeorgieBoy]

You have a hydro-boost system where hydraulic pressure from the power steering pump is used to provide power to the brake master cylinder instead of vacuum like most systems. Your problem could be somewhere else in the system, not just the power steering pump. Could be in the boost cylinder attached to the brake master cylinder or a bad hydraulic line restricting flow. If you don't know the system, I would take it to a shop. Losing fluid like you did not only affects steering but your braking, as you found out. The whining could be from improper bleeding allowing air to stay in the system. If you do a steer right/steer left lock to lock, while maintaining fluid level, that should purge the air out of the system.

 

[mel s]

Sounds like you have a fairly large air bubble in the system (Power steering also powers brakes) as the air expands due to heat .. Well, you  described what is happening.

But frankly. I do not know how that could have happened.

John From Detroit
On my coach, (a '96 Safari), the procedure to remove air from the hydraulic PB/PS system is:  Turn the front wheels all the way to the left and all the way to the right with the steering wheel....(4-5 times).

 

[kiss6669]

You have a hydro-boost system where hydraulic pressure from the power steering pump is used to provide power to the brake master cylinder instead of vacuum like most systems. Your problem could be somewhere else in the system, not just the power steering pump. Could be in the boost cylinder attached to the brake master cylinder or a bad hydraulic line restricting flow. If you don't know the system, I would take it to a shop. Losing fluid like you did not only affects steering but your braking, as you found out. The whining could be from improper bleeding allowing air to stay in the system. If you do a steer right/steer left lock to lock, while maintaining fluid level, that should purge the air out of the system.

Did the L/R bleed method for a while (10 times or more) and drove around the block. When I parked it back home it back flowed again. I plan to systematically check all the lines in the system tonight when I get home.

 

[kiss6669]

As always, thanks for the guidance and suggestions. Last night I started the rig and slowly moved the wheel back and forth and the noise dissipated a bit. Turned it off and then pumped the brakes till rock hard, slightly depressed the pedal and started the MH and the sound was nearly gone. So air was my culprit and I just wasn't patient enough to get the air out of the system.

 

[JFN]

Thank you for posting the results!!