Hydroboost into a 67-72

[JJorgensen52]

The answer is the hydroboost came out of a metric brake square body truck - diesel or 3500 series, '81 - '91 (mine was an '87). Hydroboost first appeared in '75 to my knowledge, any square body truck unit should work out for this.

And as above, Astro/Safari and Express/Savana vans are pretty readily found in junkyards and many have hydroboost units in them.

[Billyburban]

Thanks for getting back to me. I have a 70 suburban I picked up a hydrobost off the van with master cylinder with proportion valve now to figure out the plumbing. Dose any one know the thread patterns for the stock 70 Chevys so I can purchase the adapters. CPP sells a kit for $115.00 an I don't want to spend that much money on fittings that may cost $30 bucks.

[JJorgensen52]

Originally Posted by Billyburban

Thanks for getting back to me. I have a 70 suburban I picked up a hydrobost off the van with master cylinder with proportion valve now to figure out the plumbing. Dose any one know the thread patterns for the stock 70 Chevys so I can purchase the adapters. CPP sells a kit for $115.00 an I don't want to spend that much money on fittings that may cost $30 bucks.

Referring to the power steering lines?

[Billyburban]

The ones that go here also the Power steering reservoir

[JJorgensen52]

Originally Posted by Billyburban

The ones that go here also the Power steering reservoir

If memory serves, they're 5/8"-18 pressure side and 11/16"-18 return (inverted flare nuts), and 5/8"-18 into the pump, but not 100% on that ... I would double check.

[Ozzy2013]

I would save it they are a great set up and not cheap rebuilt or new hell if it was good ill buy it from you for a spare if you dont want it

[Ozzy2013]

Originally Posted by JJorgensen52

I did some research on this a while back, and it seemed like every thread I found talked about drilling holes in the firewall or other modifications that made this swap difficult to do.
In looking at donor trucks, it seems like only the metric (1980+) trucks had the type of booster I'm working with here.

Anyways, some pictures:

Comparison between an unmodified '87 hydroboost bracket and my '72 power brake booster


Lining up the center holes puts the pushrod in the center of the hole in the firewall. I should note that the hydroboost had two pressed-in studs in the center holes, which I popped out.


Using two snug fitting bolts and a welding clamp, I carefully lined up the two holes and marked for the other holes I needed. It's tough to see here, bu there was a stamped bend in the top of the hydroboost, which I pounded flat prior to marking (just below the top holes)


After drilling three new holes and some cutting and grinding, this is what I came up with. The cut on the bottom right was to allow me to bend the bracket out slightly to clear the flange around the steering column on the firewall.

Bracket dry fit on my '72 cab


And here's the donor hydroboost bolted in place



I had to make zero modifications to the firewall, except pulling out the original rubber linkage boot.

The photo doesn't show, but mounted like this the hydroboost pushrod is about 5/8" too short (and offers no adjustment). Unfortunately it's a smaller diameter than the adjuster end on the 67-72 style pushrod, so either I will cut and thread the rod and thread a piece of tubing to make an adjuster of my own, or I'll modify the pedal to move the pivot closer to the firewall.

Did mine the same way no need for any brackets and its clean and looks factory .I just welded two brake push rods together and made it adjustable .Love these hydroboost!

[Shack]

Originally Posted by JJorgensen52

Since I was using the square body lines, I mounted it on the front cross member just like they do. I used the square body cross member for the sway bar mounts, but the same position will work on a 67-72 cross member no problem




I happened to have a second '67 truck harness laying around, and the harness - prop valve wire is made in two pieces with a connector where it leaves the main harness. By pulling that piece off my spare harness, I was able to plug into the extension already on the '72 and reach the prop valve on the cross member no problem.

I know I'm resurrecting an old thread but I cannot for the life of me find that proportioning valve anywhere. Where did you get it and what's the p/n? Thanks in advance.

[JJorgensen52]

Originally Posted by Shack

I know I'm resurrecting an old thread but I cannot for the life of me find that proportioning valve anywhere. Where did you get it and what's the p/n? Thanks in advance.

It's from Inline Tube, their part # PR102.

LINK

[Whitey__62]

Any chance we can get the pictures working again?

Looking to do this swap shortly on my 68 C30. Seems like this will help me out a lot.

Are the hydroboost on covered with 80-91 square bodies or do the newer body styles have the same brackets?

Thanks.

[jeffahart]

Originally Posted by Whitey__62

Any chance we can get the pictures working again?

Looking to do this swap shortly on my 68 C30. Seems like this will help me out a lot.

Are the hydroboost on covered with 80-91 square bodies or do the newer body styles have the same brackets?

Thanks.

If Jjorgensen52 does not come back with images I can augment (looks like the photo bucket people are holding images for ransom!). I just completed an install off an 85 cucv into my 70. Not much to it, though there are a couple small items you need to consider. What axle are you running up front for your discs. I do think it is smart to get the master that matches the booster.

[Whitey__62]

Originally Posted by jeffahart

If Jjorgensen52 does not come back with images I can augment (looks like the photo bucket people are holding images for ransom!). I just completed an install off an 85 cucv into my 70. Not much to it, though there are a couple small items you need to consider. What axle are you running up front for your discs. I do think it is smart to get the master that matches the booster.

Yea it seems that anyone in the forums using the Photobucket group has no rights to share their own pictures, funny how that works!

I will be matching the master with the front brakes.

I have a 68 C30 high GVW that I will be swapping a 84 CC C30 single wheel High GVW crossmember/brakes. I'll find a 1ton of the same GVW to get the hydroboost, the plan is to keep it a true 1ton but with better brakes and lowered. Should make for a nice tow rig.

[weq92f]

Dang! The PB fiasco beat the crap out of this thread!

Not going to be an easy fix ( for this and soooo many other threads across the Net ) either unless PB relents.

-klb

[AussieinNC]

All, re the PB issues...its a simple fix...dont use PB...

Save your images to your local computer, then upload them from your local computer...

PB and others are simply trying to maximize revenue, using your own pics as assets...just dont use PB or other file sharing environments...

[JJorgensen52]

Hey guys:

Yes I still have all the images, and I am hoping to start restoring them all when I get home from my current work trip. Sorry for the inconveniences, meantime. Photobucket cutting the links has made it hard to determine what all of them were, so it is going to take me a little time.

[Whitey__62]

Originally Posted by JJorgensen52

Hey guys:

Yes I still have all the images, and I am hoping to start restoring them all when I get home from my current work trip. Sorry for the inconveniences, meantime. Photobucket cutting the links has made it hard to determine what all of them were, so it is going to take me a little time.

Great!! Look forward to the updates. In the process of slicing the parts now. So that would be great.

[AussieinNC]

Originally Posted by JJorgensen52

Hey guys:

Yes I still have all the images, and I am hoping to start restoring them all when I get home from my current work trip. Sorry for the inconveniences, meantime. Photobucket cutting the links has made it hard to determine what all of them were, so it is going to take me a little time.

There is a work around for the photobucket image lock on shared images...the user needs to install a plugin program into their chrome or firefox browser...

See my previous post:

http://67-72chevytrucks.com/vboard/s...d.php?t=746054

No fix yet for Internet Explorer...