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jehm101 · 05-19-2022, 02:39 PM

Could someone help me figure out what is wrong with my hydro boost, power steering and bakes please?

I jacked the front end up and turned wheels stop to stop 10 times and then brakes pumped 3 times with engine off and repeated this 5 times. I then turned the engine on and repeated the process again at least 5 times until it seemed like all the air was out of the system and the reservoir stayed at a constant level. I then lowered the front end and repeated the process again and almost immediately it went to [Mod Edit] again and air was introduced back in the system and the reservoir.

The best the system was is right before I lowered the front end and it seemed like it worked perfect from putting it in park and then drive and the parking brake turned off within a few seconds and the power steering did not squeal with turning the steering wheel and applying the brake in park and in drive.

I’m back where I started. When I start the engine in park and apply the brakes a few times it starts to whine and then turning the steering wheel it will also whine. I’ll put it in drive and sometimes the parking brake light stays on but the brake releases and sometimes the light goes out after pumping the brakes several times. It does not seem to be leaking or sucking air anywhere except at the overflow. I forgot to ad that I also bled the park assist. I do t want to start replacing parts if not needed but I have no clue what is wrong. Also the reservoir would get hot when the front end was down and I turned the steering wheel.

Do you think something has failed?
Do you think I need to try to raise up the front end again and repeat the bleeding process?

Thank you in advance,

Jehm101

donr103 · 05-19-2022, 08:49 PM

Sounds to me.. you need new power steering pump .. it really should be called a hydraulic pump.. because it powers the steering, brakes and parking brake.. I think..
Does your parking brake get power from power steering ? Or does your park brake have seperate pump? Easy to tell.. just find parking brake actuator and look and see if there is a separate pump..
If power steering pump was ran dry.. then most likely burnt up..
It is a big job.. but can be done.. I put a new one on mine..
You can see no leaks?
Go to AUTOPARK.COM and for older systems there is a bleeding procedure there..
My system is newer .. 2000.. and I have an electric pump for parking brake.. so p/s pump powers brakes and steering only..
You have checked no leak at parking brake actuator.. right? No leaks anywhere.. right ?
Good luck and keep us posted

jehm101 · 05-20-2022, 06:34 AM

Click image for larger version

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Above is the setup for my power steering and brakes.

Today I will clean every line and hose on the system and double check to see if I can find any leaks. I did find a leak last week on one of the lines to the control valve and tightened it up and have been watching it, it hasn’t leaked since. I believe that is how air was introduced to the system originally. I did read something about if there was still some air in the system and the parking brake actuator was disengaged then more air can be introduced to the system. I think that might be my problem. The last time I bled the system I put it in drive and disengaged the parking brake. After I clean the lines and find or fix any leaks I will try to bleed the system again but this time slower and more turns of the steering wheel.

donr103 · 05-20-2022, 08:25 AM

Yes.. that is the type of system I thought you had.. so if you pump is original.. it is most likely time.. on mine because it was so old.. I could not find a pump.. and when I did.. it was north of 500.00
So I just used one off Chevy 2500 same yr and eng.. I used that to look up part at AutoZone.. then wrote part number down and got a rebuild pump for 60.00 or less..
I had to re use my old pump case.. and ofcouse one hose was on too tight.. I had to cut..
You will need to get a pulley tool.. a/p store rents for free.. the line I cut.. I had to have made at hydraulic line shop..
It's not hard if you are fit.. because I have physical limits.. took me more than a yr.. but that is ok.. for me.. because I am used to things taking me a while..
A fit person.. should be able to do in 2 or 3 days.. if you have never done one..
You have to make sure.. you don't tear up pump housing.. because you need to re use it..
1st.. to might want to check.. and see if you have any inline filters.. and use a bore scope camera and look inside the reservoir and make sure you don't have a filter in there or any crud blocking that.. you might have to suck out p/s oil to check it closely..
I had all kinds of crud in bottom of mine.
Good luck and keep us posted

jehm101 · 05-20-2022, 08:12 PM

Today I cleaned up all the components and lines the best I could and then put carboard underneath everything, because im parked on grass, and jacked up the front end and continued to bleed the PS system. I tuned the wheel about 1 rotation per minute from stop to stop off and on for over an hour and pumped the brakes every so often. I had nothing leaking on the cardboard but this time because i went so slow, and had the radio off, i was unable to bleed the air out. when i got about one half to one quarter turn to stop on either end i could hear the air bubbling and then whining as i got close to the stops. Why cant i get the air out?

GordInWoods · 05-23-2022, 04:23 AM

This thread talks about bleeding the auto brake. Apparently back in the early 90's the power steering pump also fed the autobrake. Possibly a leak/air getting in that way? https://www.rvforum.net/threads/p30-...ng-pump.85377/

Ultimately, he had to replace the power steering pump. It was letting air into the system. Worth a read to see if it helps.