Hydroboost upgrade

D

dutka2678

Member
1973 Scout II, Dana 30 front with drum.

Will this hydroboost work? I have read that it should be from an astro van, but I do not know what this is from because the only thing left of it is the firewall. I am wanting to change from just m/c and front drum to hydro and front disc. What else will I need to pull from the truck with the hydro?

I am going to buy a front disc brake conversion kit. I am also going to leave the rear drums. What else would I need to get everything together?
 

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Many people have used the hydro boost stuff from the astro van. I admit that I'm guilty of it on one of my scouts. If I do it again on another project, I May go a different route.

I am not sure if IHPA deals with vanco brakes or not. But the last time I checked, vanco has a hydro brake kit for the scouts. It's been awhile since I have looked into it. Again, I'm not sure if IHPA has any kits readily available, since I haven't seen one yet. If there is one, sorry if I missed it.
 
Depends on what you can afford. Lot of it depends on what you really plan on doing with your own Scout. The all drum set-up, which is oem for the said year, in good working condition can work well. A friend has a 69 Scout with all drums which works good, and he has no plans what so ever to swap it out.

Personaly I like having rotors up front and power brakes. I have converted my 74 front axle from drum to disc using Ford brakes. If I knew back then what I know now, I would have went with the Chevy caliper setup instead of the Ford version.

Just to give ya an idea of what you're looking into asking, parts alone to convert the front axle to disc could run above a couple grand. Not to mention having to install them. This is all rough guestiments. Hydro boost might not work with an all drum oem setup. But I could be wrong, but I haven't heard or seen one installed with oem drum brakes on these ole rigs
 
I wanted to go to disc front. What all needs to be done for the Chevy caliper setup?

I only have a master cylinder with no booster. I was going to get a junk yard hydroboost and buy a front disc kit.

Is there a cheaper way to go? I am building the Scout to do a bit off roading nothing major. More like a Sunday driver.
 
One nice thing about this forum is that you can order most all these parts through the online store. And support the people who provide this forum for us to help each other out.
front GM brake conversion kit

You will be fine with a vacuum booster. Not a real neccesity to go hydro boost.
remanufactured booster

And you will need a new master cylinder to match the front disc conversion
master cylinder
This one is for disc brakes up front and drum brakes in the rear

all this ia a little cheaper than I first mentioned. Been awhile since I have looked at the prices.

**edit**
I almost forgot - you May need new brake lines too. Maybe new hard lines to plumb into the new master cylinder and new flexable ones for the front brake conversion
 
fdchappie said:
drums to work fine......until they get wet. Then for-get-about-it until they dry out.
Click to expand...

True that. Or full of mud when wheeling. Which is why I converted to disc on all four corners in my Scout. But that's a different story
 
Is there a difference in hydroboost unit from a van or 2500 series pickup? I just picked one up off a Chevy 3500hd today at salvage for future use. 4 wheel drum now w/o power brakes. Would like additional tips from anyone whos been there,done that. Thanks in advance.
 
Bracket that holds the booster to the firewall and the push rod that gets attached to the brake pedal. I have seen rods of different lengths, depending on the application. Along with how the booster is rotated and mounted on the firewall.

Both those things are the two main things to consider for this type of upgrade. I haven't used vanco brakes yet. But from what I have seen and read over the years is that his kit for the scouts will fit. Pretty much a direct bolt on. Then ya need to consider the master cylinder to match up with your brakes, weather if you have drums on all four corners or disc/drum, or disc on all four corners. Same applies to the proportioning valve.
 
I used a hydroboost from a 3500 Chevy truck. Got a bracket to bolt it to the firewall from a guy off ebay, dallas, tx area. The rod to the pedal does differ. I had to space out an inch but has bolted up fine. Still working on installing the disc brakes. New lines will be installed due to higher pressures. I was told to us a master cylinder from a 1980 corvette. I am sure they used them on others as well. It bolted up fine. Used hoses from parts store for 2004 silverado 2500. Same for ps pump. Had to change/shorten the ps hose ends to fit the smaller engine bay and gearbox fittings. Haven't run it yet to test, but bolting together nicely. If someone doesn't know how to put it all together, I would recommend a pre-engineered kit. I believe ihparts america has one.
 
I can give an opinion on a couple these questions through my experience.

I pulled a setup out of a 94 astro van, hb, mc, and prop valve. Whole thing cost me $100. Easy install and I originally used it on my 4 wheel drum setup. Thing stopped on a dime but the drums didn't last very long. I guess it was the increased braking pressures....the friction material started cracking and falling apart rapidly.

So, I decided what the heck, converted to 4 wheel disc (GM front/ caddy rear) then later decided to go ahead and switch to a corvette mc. I hated it. The stock van mc had a 1 1/4'' bore. Short, firm pedal. It made the corvette mc feel like a pillow and the pedal traveled increased more than I liked. Surprising but a 1/4" made a difference. After about 2 weeks I went back to the stock mc and upgraded reservoirs on it.

Moral of the story is:

1. The mc you choose will be totally dependent on the pedal feel you prefer. I prefer short/firm over long/softer. Some of the hb units out of the bigger trucks have bores even bigger than 1 1/4 iirc.

2. I wouldn't recommend hb with a front drums. I just think it puts to much pressure on those shoes.

Jason
 
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That is interesting about the mc. Once I have it all plumbed and lines bled, I will pay particular notice to the pedal feel. I have also noticed big differences in the past when replacing old tired brake lines. You get a better pedal feel.
 
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