[tnhillbilly]

I had to replace the pressure hose from the pump to the hydroboost and it has whined ever since. I did the wheel turn lock to lock several times while up on jackstands and mashed the brakes a few times and nothing has helped. I have never owned anything with hydroboost before and I was wondering if there is a certain way to bleed the air out. Thanks in advance.

 

[ASTROJOE LT1]

I had the same problem after I converted my 1989 to hydoboost system. I finally just let it sit overnight and tried the next morning and it was fine again.
Joe

 

[astro355]

There's a procedure for it involving turning the wheel from lock to lock and pumping the brake pedal at the same time. I can't remember it off-hand but if you still need it monday, I can look it up for you.

 

[tnhillbilly]

Hi astro355, if you can get me the bleeding procedure I would appreciate it. I fooled with it yesterday and still can't get it to quit.
:ty:

 

[tnhillbilly]

I used the bleeding procedure I got form astro355 :ty: and I still have a whine. It is not coming from the pump. It appears to be coming from the hydroboost itself. You can't hear any noise under the hood or outside the van. It is the worst sitting still idling or moving slow. You don't hear it at highway speed. Any ideas on how to stop it? It is driving me nuts. :banghead: I also have put gm fluid in it. I may try taking the return hose off at the hydroboost and plugging it and running a hose to a jug and see if it will bleed out that way. Any help appreciated.

 

[96moneypit]

my 96 with 150,00 miles does the same thing after replacing the same hose.i have tried flushing and bleeding. still have the noise. hope a member has the answer

 

[spongebob218]

Did you use a hose from GM or was it aftermarket? These vans don't seem to like aftermarket parts for some reason.

Maybe try using a vucuum pump on the reservior fill. Use a large adapter that fits the fill hole, pump it up(vacuum), and leave sit for a while. This should get some air out of the system. I have to do this all the time at work on GMC Acadias and it works.

 

[traxxasmike]

Fill your power steering fluid to the correct level and leave the cap off with the engine running. Slowly turn your wheel full lock to one side and hit the brake for a few seconds. Then slowly turn it the opposite way to full lock and hold the brake again. Make sure you add more fluid if needed and replace the cap. Thats what I did after having it disconnected during a motor swap and my whine is gone.