[64speed]

My hydraboost pedal is VERY soft but effective as hell. My problem is it’s very slow to return and I’m afraid it will be touchy at speed. What am I missing?

[TedRamAirII]

Be sure to use PS Fluid, not ATF. It may take some time and driving to work out all of the AIR. Get some miles on it!

[Lemans64]

Yes I will second that, it needs to break in, mine was slow to return at first but pretty good now.
Has been in there for a few years but got better with a few months. Google it. or ask your manufacturer.

[64speed]

Originally Posted by TedRamAirII

Be sure to use PS Fluid, not ATF. It may take some time and driving to work out all of the AIR. Get some miles on it!

I used ATF cause that’s what the pump company recommended. What’s the easiest way to get it out

[64speed]

How soft should the pedal be? It seems kinda touchy but it stops good (in the driveway at least)

[Lemans64]

Pedal will be touchy for a bit till you get used to it. Just be sure to have seat belts on it hitting it hard, LOL.
Easiest way to get a/t fluid out of p/s system is to take the return hose off, run engine and have somebody pour
new fluid in as the other goes out. Or suck it out of reservoir and fill and repeat.
Oh ya they say NOT to use ATF for above reason, too much foam and bubble's so you get air in the system.
Air is probably the biggest concern.

[25stevem]

A big Turkey Baster is what I keep in the tool box for sucking out fluids.

[64speed]

I’m pretty sure I got all the air out it’s just gonna be a learning curve on the pedal return

[Lemans64]

Had mine fired up today, 1st start over winter, but was watch ing pedal and it is slower than vacuum booster.
so ya if comparing vacuum to hydra boost, it is slow to return. But does not create an issue when driving.

[chuckies76ta]

Originally Posted by 64speed

I’m pretty sure I got all the air out it’s just gonna be a learning curve on the pedal return

How did you get all the air out of it?

[64speed]

Turning the wheel and pressing the pedal.

[chuckies76ta]

Originally Posted by 64speed

Turning the wheel and pressing the pedal.

Ok, good. It can require at least 30 turns right to left, left to right. Jack the front of the car off the ground and before starting the engine, turn wheels back and forth to purge air out. You can push pedal few time to move air out of the accumulator. Keep an eye on reservoir level so no air get introduced into system. Take your time. As air bubbles get released into reservoir, you have to wait till they disperse. After all this you can start engine and still turn steering wheel back and forth while pressing on brake. All this is done to evacuate air out of the lines.



Also, one thing I'd like to know is how did you plumb the line from the booster to the Reservoir? It's a drain line from the booster.

[mzbk2l]

Buddy of mine put a hydroboost from one of the aftermarket companies in a '70 Chevelle autocross car he built. Had a VERY hard time getting the air out and found out from a GM engineer that the way the aftermarket company was building the return line was causing the problem. (It either T'd into the PS return line before the reservoir and should have gone directly into the reservoir instead, or vice versa.) If I think of it when I see him tomorrow, I'll ask him. He made whatever that change was and never had any more trouble with it.

[Tom Vaught]

I was aware of that "Tee" issue years ago and had a second return nipple added to my Power Steering Pump reservoir at that time.

I have never had an issue with the hydroboost stuff if installed correctly.

Luhn Performance has done several of the conversions over the years.

Tom V.

The Tom Lee steering box is another one of the components which I have never had an issue with.
Tom has been out of that game for several years.

[Lemans64]

My return is T'd together with the p/s box return, no real issues. Although I have thought about adding another port on the reservoir.
wasn't quite sure where to put it. Reservoir is chrome so not wanting to mess with that either. The 3/8 O/D is only 5/16 inside diameter so it does create some restriction.
Optimal would be to have another port on reservoir.

[chuckies76ta]

Originally Posted by mzbk2l

Buddy of mine put a hydroboost from one of the aftermarket companies in a '70 Chevelle autocross car he built. Had a VERY hard time getting the air out and found out from a GM engineer that the way the aftermarket company was building the return line was causing the problem. (It either T'd into the PS return line before the reservoir and should have gone directly into the reservoir instead, or vice versa.) If I think of it when I see him tomorrow, I'll ask him. He made whatever that change was and never had any more trouble with it.

Good info. I seem to recall when I install my first unit on my 76 TA that I had issues with the return line t'd. I removed it and installed (welded) a -6 an fitting on my power steering pump. Been working fine for years.
I just installed a Hydraboost unit in my wife's 68 Firebird and I had my son tig the fitting on the side. Works great. It's easy to pull pump apart, but don't bend any of the sealing areas on the housing. One other issue is too make sure your pump has the higher boost valve installed. I believe the pump puts out 1200 psi on pressure side. I just bought myself a new power steering pump and welded the fitting on the side.
https://www.tuffstuffperformance.com...s-saginaw.html