Buick Grand National convert to Chevy 3500 hydroboost.

[Regal_T-type]

Truck guys help!

So Ive made this horrific chimera of a hydroboost for my turbo regal. The back half is from a 79 cutlass diesel, the front half and piston are off a chevy 3500 dually I found in a junk yard.

Question is do I need to use the JB8 master cyl? Is there a smaller/weaker master that will fit?

Car is 3600 lbs and its brake system is essentially identical to an 80s 2wd S10.

Will the JB8 explodicate my wheel cylinders?

Will I lock up and die?

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[454cid]

Why do you need parts of two units? Could you run the Astro van booster and master cylinder?

 

[Regal_T-type]

The astro van unit does work, however you need to shorten the pedal rod or make a spacer in order to use the factory pedal, also the astro unit wont work with the 84 regal turbo pressure hoses.

The 79 cutlass booster I started with fit the firewall and stock pedal perfectly. The regal hoses did not work with this unit. So I took the hoses to the junk yard and test fit them on the hydroboosters i could find. The booster from a 3500 fit the hoses perfect.

Combining the 2 parts gives me a 100% bolt on unit.

The only bolt on factory unit that I know of is 52-7211 from an 84 Regal carborated turbo. The company that remans these units recently stopped so finding them in parts stores is about impossible.

Another possible benefit to the the turbo buick crowd is that the higher pressures generated by the 3500 master cylinder may allow upgrading to 4 wheel disc and multiple piston calipers without spending thousands on a wilwood system.

If I was evil I could assemble all the left over parts, paint it and return it to autozone to make this kit nearly free. I wouldn't do that though

 

[454cid]

The astro van unit does work, however you need to shorten the pedal rod or make a spacer in order to use the factory pedal, also the astro unit wont work with the 84 regal turbo pressure hoses.

Is one SAE and the other Metric? That should be as easy as using the Astro pump, I would think. It seems to me that a carefully adjusted rod would be better than building a hybrid booster. If/when it goes bad, you would simply get another, not build one from two.

 

[Regal_T-type]

I could be very wrong about the fittings on the astro booster, I haven't actually found one in a junk yard to try. From what I hear the astro rod is at least an inch too long and needs to be cut down and welded.

Other than the piston and bore diameter the internal components on the boosters I used are identical and interchangeable. All I did was swap the truck piston onto the oldsmobile rod. Its held in with a single rivet, I drilled this out and replaced with nut and bolt. Took about 15 minutes to do the job.