Hydroboost Conversion

[TexasT]

Since it seems they local board requires logging in to view I am posting this over here for easier access.


A little back ground, my car has lead a rough life. The original powermaster went out when the car had pretty low miles(like 30k or so), but i had it replace with another powermaster to the tune of about $800. I didn't know any better at the time. It worked until about 125k miles. When it would no longer assist braking it was decided to swap to a hydroboost. I have the hydroboost on two GM trucks and it was on the 84 T-Type I traded in on the current T. I didn't like the look of the big iron master cylinder so I opted for the Cadillac unit with the plastic reservoir. Funny because I can remember thinking, "why would anyone want a plastic master cylinder when you can have the security of a nonleaking iron one when I put new ones on vehicles like my GS and Blazer. I guess perceptions evolve.


 I did some reading and ordered the parts recommeneded at the http://www.cedarcrestspeedlab.com/techarticles.html?col7=open#CollapsiblePanel7  . This link also outlines the pressure line mod that is required to fit that hose onto the 86-87 power steering pump. Ill include pix of how I accomplished it.I ordered the parts for an 84 TR from rockauto.com. I hear that the cores are getting scarce so I have been picking them up when I see one for sale. These hydroboost units dont have an accumulator like the newer astro van pieces but they are bolt in. I think the accumulator gives a false sense of security as I have had the Suburban chuck a tensioner pulley thereby loosing the belt(and power steering pump). You got non assisted steering and non power brakes in a hurry, and this truck has the accumulator.. SO, inspection of the pulleys and belt are in order at each oil change to prevent this scenario.



These are the hoses I ordered.







Booster






Master Cylinder






As you can see the hydroboost came with the actuating rod already on it.



Locally, I bought some additional pieces, including a brass tee, and some trans cooler line to tee the return into the power steering return line.






A line wrench so as not to round off and fasteners. This was a cheap one from autozone. I called around but was unsuccessfull, and made a trip by sears and harbor freight with no luck. I didn't see a tool truck so I bought this one and it worked fine.

[TexasT]

On to the actual work.


We removed the powermaster and associated bracket and ran into a snag on the pedal. The cotter pin was corroded and didn't want to come out. I wrastled with it and cut off each end where I could slide the actuating rod off the stud on the pedal. I heated the stud up in an attempt to get the remains of the cotter pin out but ended up drilling the pin out. Then a trip to the part house for a cotter pin assortment to replace the disintegrated original.






When re-installing the pedal I unknowingly bolted it all up with the idea that I could slide the actuating rod eye onto the pedal stud, but I was wrong and ended up unbolting it and installing the actuating rod to the pedal, THEN bolting the pedal and hydroboost to the firewall. This little bit of info could potentially save you an hour. As I wrastled with it under the dash for quite some time before it was deemed necessary to unbolt.
Then we bolted on the master cylinder.





It should be noted, we had to "massage" the brake lines to fit the master cylinder as the front line on the powermaster goes to the rear on the master cylinder and the rear line goes to the front. Not had, just be careful you don't kink a line by being to rough when performing the "massage".

[TexasT]

On to the lines and such.



To get to the power steering pump I found it necessary to remove a few items. Your desire to remove or maybe you have little hands may vary. I pulled the intake tube/maf, alternator, intercooler(i cleaned it out while I had the other things apart), a/c compressor(I just laid it to the side, no need to disconnect the lines), to get to the top of the power steering pump. This is where the flare wrench was used. I didn't want to round off any fasteners.






As you can see I used a screw driver as a lever to "massage" the line where I wanted it. Not hard. I took it in small doses and trial fit it until I liked how it sat and didn't rub on anything. Not hard. I also want to mention that there are o-rings that go on each end of the line. When removing the old line from the pump, you need to be sure the o-ring comes out with the line as two o-rings in there will result in a leak. You don't want to have to take the accessories back off to correct a leak that can be prevented.





Then we tee'd into the return line to complete our circuit.






Return line off the hydroboost.





Once you have the accessories re-installed, you must "burp" the power steering / hydroboost setup. Get the belt back on and make sure you have the rest re-installed so you can jack up the front wheels and run the engine. Top up your power steering reservoir, and have some fluid handy to keep topping it off. You don't want it to run the reservoir dry as this will just make burping take longer. With the engine running,(Id have the rear wheels chocked or jacked up as you dont have any brakes at this point, and you'll need to jack it up to bleed anyway.)With the engine running, and the front wheels up, turn the steering wheel lock to lock several times to burp out any air in the system. You should see some foaming in the reservoir and hear the pump a little as you are doing this. When there is no more foam I think you have successfully burped the system.


On to bleeding the brakes. I don't know how anal you are but my car had never had the brake fluid changed except I guess when the powermaster was changed way back when. The fluid was pretty brown and rusty so it was deemed necessary to flush out the system with new fresh fluid. I recommend you do the same.


 I started out by bleeding the master cylinder on the car. I put a two x four under the pedal to prevent the pedal operator from putting it all the way to the floor. We cycled the pedal several(ok many) times to get the air out. Safety glasses are a good addition at this point, no sense in getting brake fluid in your eyes. Once you stop seeing the little bubbles it is time to hook up the brake lines to the master cylinder. As noted above the front to the powermaster goes to the rear of he hydroboost master cylinder and the rear goes to the front. Some careful "massage" gets these lines to where they need to be. To get the cruddy stuff out into the hoses and catch containers we opened the rear bleeders and put the hose and catch container on and manned the master cylinder with fresh fluid so it would go dry and we would have to start again. Once I started getting clean fluid I bled the rears starting with the pass rear, moving to the dr rear then moving on to flush the fronts and bleed them too. My car has pretty much resided in Texas except the year we spent on an adventure in southeast WI so the stuff under there is pretty easy to work on. Your car might require some new parts to complete the bleeding. I bought some speed bleeders but ended up not using them. I just got one of the "helpers" to operate the brake pedal while I did the bleeder/ hose/catch container.


Once bled to satisfaction with no bubbles coming out at the catch can we buttoned her up, put her back on the wheels and went out for a test drive. After a trip around the block it was deemed good for longer trips. So we went to the parts house for some wiper refills so we could try for a safety inspection.

[TexasT]

ANY questions?

[daveismissing]

Hydroboost uses the PM pedal dimensions vs the Vacuum pedal dimensions?

[TexasT]

I'm not sure on the vac pedal. This is one of the reasons I chose to go with the hydroboost so I wouldn't have to locate and purchase a vac pedal. Not hard to locate but just another hassle I didn't want to undertake.

[1KWIKSIX]

 Believe you are correct Dave......doin g the conversion, the HB system requires the use of the brake pedal from the PM system.

[TexasT]

I guess I didn't understand the question. Yes Hydroboost and Powermaster use the same pedal. Vac is different.


Thanks for clarifying 1kwicksix

[TurboCajun]

does anyone have a diagram of the connections or routing, I am working on an 84 with hydroboost and converting to 87 setup and want to keep the hydro. but I need to know how to tap in the lines

[TexasT]

I guess I am unclear. You already have it on your car, right? Are you changing power steering pumps while upgrading to the 87 stuff? Surely the steering box is staying and so is the hydroboost unit.


If swapping in the 87 pump you will need the 87 reservoir.


I don't have a diagram but I believe the pump has a pressure line that goes to the hydroboost, then the hydroboost has a pressure line to the steering box.
The steering box and the hydroboost have drain back(low pressure hoses) to the reservoir(they are tee'd).
And the reservoir has a line to the pump to complete the circuit.

[TURBOPOWERED68]

why didn't you use a hydroboost pump with the reserve?

[TexasT]

Have you priced that setup? I don't know about you but I have a wife, four children and a mortgage. It didn't even come close to my budget.


That reserve ain't much imo. I have a Suburban and a pickup with that setup. I've had the burb chuck a tensioner pulley and you are in no power steering and no power brake land in a hurry.

[daveismissing]

I'd think with a bit of research one could find an industrial accumulator that would not break the bank. That's all the PM's current replacement is.

[earlbrown]

The expensive kit above looks like an Astro van unit.   Except that Astro units aren't that expensive, that is.

[TexasT]

No, astro van hydro boost is very attainable. The rest of that kit drives the asking price north quite a bit.
I chose to go bolt on because it bolts on. Used the pwrmstr pedal and pretty much bolted the rest in place except the tee which in volved the tee and cutting some rubber line and the massage of the one presssure line as shown in the link to the cedar crest speed and here. If the pedal wouldn't have been different I might have gone vacuum.