94 Southwind Hydroboost / Power Steering / Brake Issue

[pldwilli]

Hello all, I'm new here and looking for any advice on an issue I'm having with the power steering and brakes on my motorhome.
Its a 1994 Fleetwood Southwind built on a 93 P30 chassis.
the power steering pump was making an awful squeal a few weeks ago, I removed some of the fluid and replaced it with an equal amount of power steering repair fluid. after about 5 miles down the road the sound went away and everything seemed good.
Just got back from a long trip about 2600 miles. on the way home the squeal started again and then the power steering and power assist brakes quit working altogether about 800 miles from home. Checked the power steering fluid and it was leaking all over under the motorhome because the reservoir was completely full, when I left it was at the full mark which is about 2 inches down on the stick. At this point I was thinking that there was an air bubble somewhere in the system, so I tried bleeding it by turning the wheel back and forth. this did get the fluid level to go down in the reservoir but as soon as I put the motorhome in gear the pump stops working and the park light will not go out. put it back in park and the pump starts working again (sounds awful, but it works).
At this point I'm kind of at a loss, I don't want to replace the pump if its something else like the parking brake or some other part of the brake system.

any help pointing me in the right direction is greatly appreciated.

 

[texaslime]

Sounds like the power steering pump bit the dust 

 

[Lou Schneider]

The squealing could be the fan belt slipping on the power steering pump pulley so the pump stalls when it's placed under a load.

The fan belt could be worn too thin, or may be too loose to transfer full power to the pump.

One way to test the pump on a Hydroboost is to turn the steering wheel while pressing on the brake.  If the pump isn't putting out enough pressure to run both of them simultaneously, you'll feel the brake pedal or the steering wheel pulsate.

You may also hear the fan belt squeal if it's slipping under the heavy load.

 

[darsben]

The full mark on mine near the top states "FULL HOT" and there is another mark very near the bottom for full cold. IS yours the same as mine? could it be overfull?

I have read on the hydroboost repair parts sites that the hoses will fail from the inside out. Could this be your problem? If a  hose fails that could be the problem.
First you need to bleed the system correctly using the instructions found at
https://www.larescorp.com/tech-tips/hydroboost-system-bleeding-instructions/

 

[pldwilli]

Going to check the belt tomorrow, seems to make sense since the pump works while in park, stops working when in gear, and then if moved back to park and you rev the engine it starts working again. doesn't really sound like a belt squealing but it makes sense.

Next question, is this the main serpentine belt or a different auxiliary belt?

 

[pldwilli]

the stick on mine has a line for add and then a bunch of hash marks for operating temperature up to another line that says adjust parking brake. from reading the manual when its cold it should be at or above the add mark and when hot it should be somewhere in the operating temperature level.

 

[udidwht]

The stick add mark points towards the end of the stick approx. 1/8th in from end of stick. Next up would be the (full) cold mark and further up the (full) hot mark.

I'll measure the marks and post the specs up for you. As for the belts you'll need to do the power steering one with the tension on the other (2) belts slackened. Power steering belt first then the AC/power steering belt and then finally the serpentine belt last.

At operating temp as long as the fluid level is between the full cold and full hot marks you're fine.