Well, I just got my car back up and running and found some interesting thigs out about my hydro boost system. Here are some pointers you need to keep in mind for the conversion, or if you are currently having issues with yours.

Stuff you will need:

-Go get a LS1 (98-02) master cylinder and swap the rear to disks. You have to machine a stock master to fit on a Astro van hydroboost. The disk/disk master may cause poorly working rear drums.

-Find a Astro hydroboost, grab eveything with it you can. Not sure of the year, but the style that comes strait out from the firewall, not the one that points down. You must get the firewall bracket, but try and get the lines and hoses too. (I rebent the lines to work with my application, dont use your hands, use a bending tool and a little heat if needed)

-If you dont have two return lines for your power steering pump, you can add one with a bulkhead fitting to the pump case or find a truck hydroboost PS pump housing. You have to take the pump off of the housing so you get all the metal out from the modification. An astro reservoir and pump might work or be made to work for both return ports. (Astro's have one return on the pump and one on the reservoir)

-You will need the bracket from the rear of the factory booster and the rubber boot to seal the firewall. (you must trim it to fit)

-You will also need to either cut and thread the rod from the hydroboost and factory booster and mate them together, or measure, cut, and weld the two together.

Stuff you need to know to make it work right the first time:

-The return line fitting cannot be replaced, it is a metered fitting that only allows so much fluid to pass through. It is also an O-ring type fitting and not a pipe plug fitting. Changing this fitting out will change how the system functions and should not be done.

-All the pressure lines are fair game as long as you can find the correct fittings and hose.

-You must run a seperate return line back to the reservoir for both the steering gear and hydroboost. "T"ing the lines together does not work. The return from the steering gear has enough volume to back up into the hydro boost and apply the brakes. (I burned up my new rear rotors and pads in just 4 miles) If you are unsure if this happening to you, start the car, jack up one side and try and rotate the front and rear wheels, if they have drag, or wont turn, you have a problem.

-Do not put a cooler on the hydroboost return line (see above). There is honestly no reason for it. Fluid barely trickles out of the hydroboost return line. Put a cooler on your steering gear retun line.

 

The T of the return line mentioned above has me wondering. Almost every illustration I've found shows this method.

Has anyone else other than the above guy had a problem?

-- Joe

 

I figured it out by researching it on the net. Lots of full size truck guys make the conversion and they found the problem. I trouble shot it by taking the return off the "T" and plugging the T and routing the return for the hydroboost into a bottle. The brakes stopped locking up. I do run a wilwood prop valve and I dont know if that mattered or not.

 

I wonder if a one way valve fix it.

I could tap and put a second return on my pump but, I'd prefer not to. Supercharge is in the way

-- Joe

 

I have a swapped in LT1 and I run a remote P/S reservoir so it was easy to plug a second return port.

 

Anyone mind if this gets linked to another thread about low vacuum and power brakes?

https://www.thirdgen.org/forums/brak...e-upgrade.html