Hydroboost Help needed

[Curturbo]

I have an 85 Grand National with an 87 setup and 87 remanned pump on it. Everything... and I mean everything in the system has been replaced on the Brake/steering system to fix this problem... '85 Lines, 87 Pump, '85 Gearbox and HB unit itself. What is happening is the horrific whine and pumps failing. I have bled it correctly with no bubbles in the reservoir. The returns T into each other about halfway between the Gearbox and HB unit. The Reservoir is Custom made aluminum with -10 an feed to the pump and it is vented. The whine seems to get worse with temperature but is always bad at higher rpm regardless of temp. Im sick of listening to it and replacing parts with no change.

What I think could be the problem:
Need a cooler on the return line?
Need an acdelco pump rather than an oreilly reman?
Unrestrict the return from the HB unit to the reservoir?
Smaller or Larger Pulley on the Pump itself?

Now, when I finally got the car finished two years ago, I was told to use auto trans fluid and it was whining for a while until I pushed the brakes really hard, it felt like there was a pop on the brake pedal and it stopped whining. This lasted for about 5 hours until one of the home made lines that was on the car when I bought it blew off. It has constantly whined and destroyed pumps ever since and everything was replaced after the auto trans fluid. I have a 4" open downpipe so I wasn't really all too worried about the noise, but I am putting an e-cut and stockish exhaust on it so I want this whine to go away.

Any Help is Greatly appreciated. I have read every hydroboost post, to my knowledge, that I can find on here and haven't found any solid information about this problem that I haven't tried. Thanks For Listening.

 

[charlief1]

The first problem is you're using tranny fluid rather than the GM recommended power steering fluid. Power steering fluid is thicker than tranny fluid and has different additives than tranny fluid does. There's a whole write up in the how to section on converting to hydro boost and it's got diagnosis help in it as well.

 

[TexasT]

I see a comment about a restricted return line, is this correct?

Mine is done with lines from rock auto and a fabbed trans cooler line teed in as a return. Id look into the factory style lines and an unrestricted return.

Let us know how you make out.

 

[Hot Air]

powerbrakebob rebuilt my hydroboost years ago and it is fine. Yes, use power steering fluid. Why use ANYTHING else? I also bought braided hose kit from Bob.
Conrad

 

[Curturbo]

I apologize I should have specified that this only had auto trans in it that one time before the line blew off. I only mentioned that because I wasn't sure if that was a reason that it wasn't whining. Since, it has been strictly powersteering fluid with lucas added in. I read about slick 50 so i am going to try that with a cooler. and if it's not that i'll drill out the restricter. The worst that will happen is I will have to weld the restricter back into it.

The Fitting that is coming out of the HB unit for a return looks to be like a factory fitting with a smaller hole than a fitting that size should be so I wasn't sure. When I bought this car, it wasn't running, and the guy I bought it from literally had a pump that rotated the opposite direction on it so this has been a quest to get it this far.

And as far as the how to on converting to hydroboost from pm that is on the forum, I read through it three times last week trying to find something useful that I hadn't already done.

Another thing, at one point before replacing everything else, I had been trying out different feed lines to hb unit from the pump. The First was a -6 stainless braided that actually pushed the inner lining through the braided stainless so I figured I needed a heavy duty line so I had some high pressure ones made and one was a -8 and one a -6. I never used the -6 because when I used the -8 it destroyed the pump for reasons I am not understanding at this point.

 

[Chuck Leeper]

Dum ?? It's not plumbed backwards, is it?? [Had to ask. BTDT!]
Borgeson has a pressure shimming kit that will drop the regulated psi, depending on the # of shims installed. [About $18.00]
What's the capacity of the resevoir? [TR's had a boiling the fluid issue in the mid 80's. Mine did it,[1986], and the dlr replaced it w/ a larger tank.]
Pedal travel/freeplay correct?

Slick 50??? U R kidding, right??
I use Lucas and real P/S fluid in my 55. No problems..2100psi at the wheels!

 

[charlief1]

Slick 50 used to make a power steering fluid that worked really well Chuck. If you ever had 1 of the ferd pumps that whined all the time it usually kept them quiet when nothing else would work.

 

[Chuck Leeper]

When he mentioned Slick 50, I thot of the "motor honey" shyt they sold. I had a BAD experience w/ that bunch..i sold some cases of it, and the guy I got it from scammed a school dist w/ it. The long arm of the law came calling!

 

[charlief1]

Motor honey has 1 use as far as I'm concerned. It's great for knurling valve guides and that's about all.

 

[Curturbo]

So here is an update for those of you that are interested... I added a small trans cooler in the return line and used only lucas powersteering fluid and It made a substantial difference. I still notice a bit of a whine during long highway cruising at higher rpms and when it's really hot. Other than that, I am going to make a larger reservoir and hope that will eliminate all whine. I will follow up.

Also, My brake pedal is getting pulled towards floor when the engine is running... and I actually have to pull the pedal up to release the brakes completely. Anybody have any Idea what might have caused this. I thought it was from the brakes not being bled properly, but I can't understand how that would work.

 

[turboc87gn]

Idk id tear it all off and start over again using teflon braided -6 line and a hydroboost with an accumulator mine wines but only when i step on it hard....

 

[Chuck Leeper]

"Also, My brake pedal is getting pulled towards floor when the engine is running... and I actually have to pull the pedal up to release the brakes completely"

Correct pushrod freeplay??

 

[turbonut85]

Booster is done. Time for a new one.

 

[usetaboost]

Just gonna throw my two cents in from previous experience. I've never understood the fascination with that lucas crap. It's fancy motor honey as far as I'm concerned. Now, powersteering pump whines I do have some helpful info I learned by standing around and watching other people work When we had about 40k on our grand am the pressure hose exploded. GM designed these cars to blow ps lines I swear. So of course my wife stops the car because she can't turn and lets it sit there and run lol! Had the car towed to the shop I worked at and they fixed it but the pump whined like crazy. One of the techs there had a tube of GM posi lube and put a little bit in with the fluid. In about an hour of driving the pump stfu. No shit, worked like a charm.

 

[GNRick]

I bought mine from Hydratech. Pump whined until I figured out how to use a screw driver and tightened the clamps on the lines. Air was getting in. Problem solved.

 

[Curturbo]

There is no air getting into the system, I would notice it in the return to the reservoir, at least I assume it's not getting air by watching that. Now it doesn't whine or make any noise until it is fully warmed up.

The booster was replaced last fall when I was trying to fix the problem. I still have the oem HB unit and the remaned is in the car currently. Anybody wanna trade two HB units for a HB w/ Accumulator? LOL thanks.