1987 Grand National Hydroboost not working

mred355

Member
Joined
Oct 19, 2004
Hi Guys. I am having a problem with the brakes. I have hydroboost and it kept getting harder and harder to push the pedal. Right now there is no power and the car is very hard to stop. I replaced the P/S pump and bled the system and no difference. I searched for a rebuilt hydroboost unit with no luck. Everyone says to send it in and they will have it rebuilt and send it back. Any ideas would be appreciated. I don't want to tie the car up and really can't safely drive it as is. I need to repair or replace unit. the part number on the unit is 527211. Thanks in advance. Ed
 
Is it leaking? Most hydroboost rebuilds consist o replacing the seals. You can get rebuild kits online and there are several YouTube videos of it.
 
Its not leaking; but acts like it has a restriction and the power steering don't turn as easy as my 1986 regal without turbo or hydroboost.
 
Sounds like hydroboost claimed another power steering pump.

When you said you replaced it, did you replace it was a parts store pump (and assume that ''new'' means ''works'')?
 
I am not sure whats going on. I changed the p/s pump and it didn't help the problem. I only drive the car about 1500 miles a year and the problem has worsened for the last two years. Also the pump is a rebuilt one from NAPA
 
Hi again. After thinking it thru, I decided to order a rebuild kit from pirate jack.
 
Hi Guys. I am having a problem with the brakes. I have hydroboost and it kept getting harder and harder to push the pedal. Right now there is no power and the car is very hard to stop. I replaced the P/S pump and bled the system and no difference. I searched for a rebuilt hydroboost unit with no luck. Everyone says to send it in and they will have it rebuilt and send it back. Any ideas would be appreciated. I don't want to tie the car up and really can't safely drive it as is. I need to repair or replace unit. the part number on the unit is 527211. Thanks in advance. Ed

Napa has them, I just checked yesterday, alot more but instock, I was thinking switching from vacuum to hydroboost.


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Ed, you should send out your PS pump to a pump specialist to modify for hydro boost . They will increase pump output and adjust gallons / minute output for optimum hydro boost use.
Jones Racing, Lee Pumps or Sweet Mfg Inc in Kalamazoo Michigan
 
Better / modified pump should help but have you checked to make sure there are no kinks or sharp bends in any of your lines? if your return line is a T fitting from the steering box to the reservoir it could be causing a restriction witch will hurt both braking and steering feel, A better option would be to use a Y fitting or return through a extra hole in the reservoir for the hydroboost and see if that helps.
 
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