Oldguard 7

What chevy trucks or cars came with hydrboost boosters and what years are used to adapt to the C3 corvette? Im considering getting a hydroboost unit. My vehicle has only 7 inches of vacuum dur to my cam. The reason ask if is some of the threads I read hydroboost units are $600 to over $1000 plus (hydratech)

HeadsU.P.

So, I guess a vacuum pump is out of the question? I often think that is the way to go. Then rip all that crap off of the back of the carb, run new hoses. Put a vacuum storage canister in place of the vapor can in the drivers fenderwell.

Its amazing how much stuff operates off vacuum on those C3s. Or should I say how much stuff doesn't operate . . . . . . .

PainfullySlow

I believe one of the common swaps are the mid-90's AstroVan units.

worship79

Here is some info for you. Did this mod myself this year and it requires a few mods here and there. Also new hoses to be made and such.

Did I already mention you have to either be or hire a circus artist to unbolt the brake booster from under the dash?

Matthew Rogers aka DB has a pretty good write-up of how to and what to purchase.

https://www.corvetteforum.com/forums...other-one.html

http://forum.expeditionportal.com/th...ewbies-like-me

https://www.corvetteforum.com/forums...steeroids.html

http://www.rockauto.com/en/catalog/g...ring+pump,7380

NeverTooOld

The problem is the C3 brake boosters don't have enough storage capacity to operate power brakes at an idle when using a long duration camshaft that produces low vacuum at idle. All you have to do is drill and tap the front of your brake booster for 1/8" pipe threads, screw a 90 degree brass elbow with a 3/8" hose barb fitting in it, then run a hose from it to your headlight feed hose;using a common "T" to join them together. I only have 6" Hg at idle in DRIVE but yet I have terrific power brakes all the time because ANY brief operation over 1000 rpm keeps the vacuum reservoir, headlight feed hose, and brake booster fully charged with at least 15" Hg or more.

Oldguard 7

Can you post pics of your set up? That might work. I may try it if it doesn't work, I'm going to manual brakes is the least expensive (compared to hydroboost) and less fabrication.

Ralphroadster

mine came from lkq 2014 chevy van 8000 miles, 80 dollars, using a willwood master 200 dollars
i don t play around with brakes,hydroboost is very good,so is the willwood master

atthemattin

You can use the hydro from a 95 Astro van. I'm still doing mine and was actually doing a write up on how to do it. I'd get one from a junkyard. Otherwise you will have to find the push rod for it and the mounting plate. The Astro also had the same bolt pattern, but I may have had to file a bit of it.

Indiancreek

I have read the same thing with the Astro Van

atthemattin

Just saw the cost point. Don't buy a kit. You wanna get a hydro boost from a Astro van from 94/95. They have almost an identical bolt pattern. You might have to file the firewall a bit, I think I did a little. But if you buy a new one, get it from Autozone. So the others don't have the mounting plate with it. You can also get them to price match it. The problem with that is that you then need to get the push rod for it. This is a nightmare since I only found one guy selling them, and he's starting to run low and he was selling them for like 60 bucks each. You could probably get a used one from a junkyard for like 120, which is still cheaper than buying a reconditioned one. After that you need to get lines made, which you can do yourself. I think that might be around 100 something with fittings. That's really all you need. I ended up going full out with a wilwood master, d8-6, and a new pump.

worship79

I used a late 80's Chevy Van (diesel engine) hydro unit. Stock master and a different pump with a dual return. The setup with the T-fitting didn't work out so well in combination with my rack and pinion.

Come with push-rod, but had to mod the rod from brake to unit in order to fit the stock clevis.

mrvette

I"d say modding the push rod was the hardest part of my install, years ago.....I have no issue with the return lines in that my car has a '88-91 vette serp drive, and so the p/s has it's own frame mounted canister...so I just used a 3/8 T fitting in the return....I also have a rack on the car, which I just got done on a 3 day excursion of changing out.....age 73 cold out, and arthritic as hell...and the SOB fought me every inch of the way....too damn old for this ****.....

worship79

Hardest part physically was the part under the da** dash getting at those bolts holding the booster. New lines etc. pretty easy, though I had to visit a hydraulics company to make them for me.