I installed the full hydroboost system on a friends 70 chevelle. I didn't do a new gear box like they suggested in the instructions, so I think that is where I shot myself in the foot. The car has no power steering and the brakes just about take both feet. I did a full March surpentine pully set with the power steering pump. I just installed a new variable ratio gear box last night, but the hydroboost instructions talk about a pressure relief valve that gets full of junk from old gearboxes. Has anyone tried to clean out that pressure relief valve in a hydroboost? What fluid is everyone running in thier hydroboost sytems?


new paint pics

http://s194.photobucket.com/albums/z292/chevynerd/70%20chevelle/?action=view&current=cars5005.jpg

I just installed HB. I don't think your problem is an old PS gearbox. It might work slightly better with a new/completely clean box but I think the HB part of the system would work fine with just about any gearbox. On my car I used the existing PS gearbox and believe me, it does not act like it has manual brakes. I can lock the brakes up with very little force on the brake pedal. I would actually like to decrease the amount of assist that my system has.

Are you talking about a pressure releif valve in the HB or in the PS pump? It the one in the pump it is just inside the pump behind the output fitting on the back of the pump. Just pull the fitting(1" wrench) and it should come right out. I never tore the valve apart but I think it would be simple to take apart and re-assemble. I have not dis-assembled my HB.

I am using basic PS fluid, I think Prestone brand.

Tyler if your using the march billet ps pump I think that may be your problem, I have heard that pump has to small of a resevoir