'78 Buick Regal Sport Coupe

[STINEY]

California yard considers this a "rechromeable core".

Yeah, around here its "driver quality". Steel chromed skin with an aluminum core brace. One more piece of the puzzle solved.

[STINEY]

Different mounting plates, push rods, and in some cases reserve canister sizes. There is a Bronco site out there that detailed a lot about the different types. The late Astro stuff has a really weird mounting plate to mount to the angled firewall and stay horizontal.

Thanks for the lead. Good reading and great info.

I have the truck unit off - it has a massive mounting plate compared to the astro and gbody units. Its really TALL, but that's just more material to work with.

[CTX-SLPR]

Different mounting plates, push rods, and in some cases reserve canister sizes. There is a Bronco site out there that detailed a lot about the different types. The late Astro stuff has a really weird mounting plate to mount to the angled firewall and stay horizontal.

[STINEY]

Yep. Lower the booster centering hole to the center of the mounting bolt square, use the power brake pivot on the pedal arm, make rod correct length, done.

Speaking of pedal arm pivots - TurboBuick guys swapping away from the factory PowerMaster system to the Hydraboost use the same pivot, while the TurboBuick guys swapping from the PowerMaster system to standard Vacuum boosters have to move the pivot DOWN 3/4", which would DECREASE pedal leverage.

I've done the power to manual pedal ratio swap on several cars - what I don't understand is the difference between the PowerMaster/HydroBoost pivot location and the Vacuum boosted pivot location?

They are both power booster systems. So the PM and HB systems use a pedal ratio closer to a MANUAL ratio? While the Vacuum ratio is all out there by itself?

Not what I would have expected to find.

(just gonna drop this here) https://turbobuick.com/threads/brake...to-vac.418576/

[SuperBuickGuy]

you saw how I did the hydroboost on my Corvette? copy that... with that said, the Buick is getting vacuum assist but then a vacuum pump and reservoir.... you do create vacuum at highway speeds, even with the draw-through turbo design.... and at this point, it's almost even money doing vacuum assist vs. hydro

[STINEY]

Today I found a third set of part numbers for the Astro Hydroboost.

So to summarize, the C-30 truck, diesel G-body car, and the Astro van all have different part numbers for the hydrobooster.

I have cobbled worse stuff together. The truck unit is complete and matches itself in the pump department anyways.

And overboosted brakes might be a good thing for this driver eh?

In it goes.

[Deaf Bob]

I have a car power steering pump on my hydroboosted flatbed.. Not quite up to par on braking and turning during low speed stuff..

[SuperBuickGuy]

Capacities as in volume/flow of PS fluid? Or boost output?

I'm fairly certain they're classed by vehicle weight - I use the time-tested method of buying the cheaper of the two and have had good luck with that.... that said, I haven't yet driven my Corvette.... but the cheaper is the more numerous, the more numerous is the lighter duty one..

[STINEY]

yes - they are all created equal except there are 2 capacities....

Capacities as in volume/flow of PS fluid? Or boost output?

[SuperBuickGuy]

Are all hydroboosts' created equal I wonder? The TurboBuick crowd likes to adapt Astro units to the G-body - I wonder how the squarebody unit compares.


Tried to look up '86 Astro application part numbers on RockAuto, but am not finding the Hydroboost listed as a replacement part under power brake booster.

I do find the '86 truck unit available from Cardone 527307 #14055057 and ACDelco 14pb4147 #19286847 for $130

Anyone know what years Astros used Hydroboost?

yes - they are all created equal except there are 2 capacities....

[STINEY]

Gotcha. I was thinking it was a Buick car of some model.

I looked up a '83 Pontiac Grand Prix Diesel which used HydroBoost and the part numbers are slightly different from the truck.

Car - AC Delco # 14bp4139

Truck - Ac Delco # 14pb4147


Car - Cardone # 527211

Truck - Cardone # 527307

All of which tells of some difference, but perhaps in configuration only? Maybe in the pedal rod?

[DanStokes]

What was your '80 exactly Dan? Maybe I can look it up to see how compatible this truck unit may or may not be?

It was an '80 C10 Diesel painted super-ugly green (I know, not significant but still true). It came with the 5.7 Diesel that sometimes ran but not in the Michigan winters so the body was tight. When I did the BBB I kept the dual batteries and the hydroboost, both of which worked great. Hope that helps - Rock Auto might have a pic.

EDIT: Here's a link for what it's worth: https://www.rockauto.com/en/moreinfo...030600&jsn=981


Dan

[STINEY]

What was your '80 exactly Dan? Maybe I can look it up to see how compatible this truck unit may or may not be?

[DanStokes]

I used the stock hydroboost when I converted my '80 to BBB power (it came with a Diesel). That worked great but I don't know how it would have worked in a lighter vehicle. I suspect that hydroboost unit was considerably bigger than the Astro unit.

Dan

[STINEY]

Are all hydroboosts' created equal I wonder? The TurboBuick crowd likes to adapt Astro units to the G-body - I wonder how the squarebody unit compares.


Tried to look up '86 Astro application part numbers on RockAuto, but am not finding the Hydroboost listed as a replacement part under power brake booster.

I do find the '86 truck unit available from Cardone 527307 #14055057 and ACDelco 14pb4147 #19286847 for $130

Anyone know what years Astros used Hydroboost?