HYDRO-VAC brakes. Who knows about these?

[Joe Chasse]

I need some help. I am installing the hydro-vac brake system (mc, pump, etc) from the 76 Chev 1 ton donor truck into my 65 1 ton Chev. Does anyone know where I can get info on the Hydro-Vac systems?
Thanks in advance,
joetruckATgmail.com
Joe

[71swb4x4]

Check out the last page: http://67-72chevytrucks.com/vboard/s...d.php?t=327476

We are doing this swap right now on my 67. What questions do you have? I am not very smart, but I may be able to help a little. My friend Todd (68c15) was the brains behind the swap so he may need to answer technical questions, but I will help where I can.

Are you swapping the discs too?

[duallyjams]

Some where in the middle of the thread http://67-72chevytrucks.com/vboard/s...d.php?t=431033 is a hydro boost install with a diagram.

[duallyjams]

Originally Posted by duallyjams

Some where in the middle of the thread http://67-72chevytrucks.com/vboard/s...d.php?t=431033 is a hydro boost install with a diagram.

page 3 post 65 has a hydro boost diagram

[Joe Chasse]

That is one bad ass 1 ton utility bed truck! WAHOO!

Y'know...I guess what I REALLY have here is a HYDRO-BOOST system as vs. HYDRO-VAC. Looks like the original matching pump is gone, so I will go ahead and order a rebuilt one if I can narrow down exactly what I need for my setup. Should come in at under a hundred bux with reservoir.

Hoping to get my rear crossmember in tomorrow evening and get those bolt holes marked, then pull the whole works to drill, and shove it all back in.

There's PLENTY to do without that pump for now, as the front end was cobbled together when I first converted to disk brakes, and now with new steering I will have fun fitting all back together in THAT department.



Fortunately the front sheet metal came off fairly easy in one piece and is waiting outside on a trailer with a tarp over it.

Thanks again for all the photos, diagrams, descriptions. I will be coming back here when I get the rest of the parts.

Thanks to my pal WOOGEROO from over at Chevytalk for turning me on to you guys!

Joe

[Captainfab]

Ummm make that post #69........

Originally Posted by duallyjams

page 3 post 65 has a hydro boost diagram

[Joe Chasse]

Looks like a great old work truck 71swb4x4, and probably just what you need for your job.
About the hydro boost brakes, I just never worked with them before and don't even know to where from where the hoses should go. Mine came from a 76 C-30 van (motor home), and did not get to see the actual hose runs.
I just took out a pretty new booster and dual hole master cylinder (MP Brakes Co.) that I put in when I put in the 78 disk brake parts (with all new seals and bearings) because I never COULD get it to work right (it will end up on Ebay one of these days).

If you are pulling off the front sheet metal from the truck, would it be possible for you to email me a picture of the rubber hose runs for the brake system?

I am also going to put the rear end from the 76 in as the brakes are MUCH wider and will match up to the 350/350 from the same donor truck.

HERE'S A LINK to pic of my rig.

Thanks,
Joe

[Joe Chasse]

THANKS duallyjams! I will snoop through the thread to see what I can find.
This is turning out to be a great messageboard! Along with the one over at Chevytalk, we have just about got it covered!

Thanks again,
Joe

[71swb4x4]

My truck is about an hour away, we are going to get it Saturday. I can get you whatever pictures you need after that.

[Clyde65]

Joe,

I love your camper/C30, that is way cool.

[Joe Chasse]

Thanks Clyde. I have updated some things, but mostly 80,000 mile original as it was built. I have added solar panels to the roof, replaced interior 'tail light bulb' lights with fleuros, swapped out the truck seat for '02 tahoe seats with built-in shoulder belts, front disk brakes, etc. etc. Kept the split rims, as they don't scare me a bit, and most tire shops have a cage. Presently installing a 76 4 bolt main 350/350 and rear end from donor truck. Hoping to run across a tilt tele steering column before I get to installing steering...

[Clyde65]

Man, you rock! I wish we were closer to ya, would love to experience your camper 1st hand.

[bubba327]

Subscribed and watching.. I have heard the Astro van had a hydro boost that is also a good candidate. I understand most any GM diesel truck or surburban had hydro boost.
This project is on my to-do list.

Captain fab makes a adapter bracket AS seen in this thread http://67-72chevytrucks.com/vboard/s....php?p=3671027

[Captainfab]

Wow that is a very nice looking camper.....very cool

We've not seen any of these on the forum in the past, but in the last week or so we have seen 2 now.


I know where there was one of these last year....I wonder if it's still there.....hmmmm.

[A.T. RockDriller]

here's mine....
answers are sure free.

it is worth the effort.....

[duallyjams]

Are you upgrading to power steering also ? if you do make sure to use a oil cooler for the hydro set up.

[Joe Chasse]

Thanks for the pictures Les! Jams, I think mine has power steering and brakes all rolled into one system. I am guessing it will need a "tee" in the return line as someone mentioned earlier.
I did drive the 1976 Chevy C-30 donor rig in and it had power steering and brakes, but I don't remember removing a cooler other than the old trans cooler that was in front of the radiator...

[Joe Chasse]

You guys are all inspiring me to pay attention and start taking pictures of the truck projects.

[Clyde65]

sounds like good insurance JOE!

[A.T. RockDriller]

Joe....
To put it briefly....It aint to tough.
If you use the remote reservoir/fill like mine, you shouldn't need an auxiliary cooler.(but like Clyde & DJ state....cheap ins..)
Also I was ordering a seal kit for my pump and the parts jockey said that the Astro/Safari booster is different than the full-size set-up......dont know what.
The pump from any full-size van or motor-home will have the remote set-up and that's what I was lookin' for.....

As far as the return lines go, all hydro-boost pumps have an extra nipple for your brake return line. That way there are no plumbing issues to worry about.
The return from the p-steering box goes to one and the rtn. line from the brakes goes to the other. If it were me....which it was,.....I would use anti-abrasion cover wherever possible.....stuffs pretty inexpensive for the advantages it provides.
I had to fab my pump mounting brackets because I sure had trouble finding a fit for the 305 V-6. Other than that it was pretty simple.......used the same pressure lines from the doner............ and that's all she wrote.

Here's a couple pic's of the top-side.

[71swb4x4]

When I pulled my setup off the 75 it didn't have a cooler. It was a hydro/ps setup that we swapped right over.

Les the pulley on your PS pump is too small for your belt, your belt should sit in your pulley a bit more.
Mine was the same way, we swapped the pulley from my old pump and that fixed it.
I don't know if it will ever cause you problems, just thought I would point it out.

[Joe Chasse]

I HAD to have taken a pump off the 76 C-30 van chassis that I got all this stuff from, but da**ed if I can find it! Here is the MC I plan to use:

and HERE is the steering gear from a 78 C-30 pickup:

THIS is the pump/reservoir from the '65 power steering:

and THESE are two 'mystery pulleys', one from the '65 and one from the '76 C-30 van donor. Don't know right now which is which.


If there WAS a steering pump/tank on that old van chassis, it HAS to be out there somewhere...of course, maybe the pump from the old '65 would do?

Thanks SO MUCH, you guys are the most helpful bunch of gearheads I have ever met!

Joe

[Joe Chasse]

I spent this afternoon turning everything upside down out in the shop and can not find that pump from the donor truck. My only guess is that when I hauled scrap metal a couple weeks ago it got itself into the ferrous pile somehow and is long gone...The pump from the 65 ran a cute little hydraulic ram down on the tie rods, I wonder if it would work with this "modern" 1978 PS gearbox?

[A.T. RockDriller]

Thanks Short-Wide.
I usually keep the rpm's under 7k or so ...so it hasn't caused me any grief so far.

I actually had to settle for the 5/8" belt for now....I'll eventually deal with it....just have to special order the right one someday.

I sure will do it though.

What do ya'll think of these hub-caps ....
They look pretty good in person compared to the wagon wheel rim look.

[duallyjams]

1 ton step vans have a t in the return line and hence the cooler also. Ask ten people a question and you will get ten different answers.