Near "bolt-on" Hydra-Boost brakes

[Bill usn-1]

Good work Stan!
I didn't have the astrovan lines so I didn't even think of that!!
: thumbsup

[scoutdiesel80]

Originally Posted by StanMcMurrey

Get the hoses off the astrovan with the hydroboost, my JY didn't charge any more to get them. I cut the o-ring ends that go to the pump and gear box, reflared them with the proper fittings. I had to rebend the tubing a little but essentially the hoses were free. I haven't pressure tested for leaks since it's not running yet but it's worth a try.

Stan,

Mine is a 1980 with the 0-ring fittings and the Astro van line from the hydro boost to the steering gear worked perfect for me and the stock Scout II power steering hose worked perfect for the hose from the pump to the hydro boost.

Carey

[scoutdiesel80]

Here are the pics.

[scoutdiesel80]

Some more

[scoutdiesel80]

Last 2

I'll install the astro van master cylinder sometime in the future.

[Bill usn-1]

Good info!!

[Damian G]

Bill,

Love the writeup, will this work on a 70s IH pickup?

[Bill usn-1]

The hydroboost has been retrofitted on just about everything.
As long as you set the push rod length right and have it pushing in a straight line, all should work.

I have seen it installed on a 60's series truck and i think jetmech put it on his 70's diesel travelette.

I did my first one about 5-6 years ago.

[Damian G]

Good stuff. I just got my 69 T-ette running last weekend, so I'm dying to get better brakes and some FI stuff going on. I'll PM ya...I have a few questions

[gmbarker78]

Bill,
Thanks for all your time and effort in showing your steps on your projects. They have been a great learning resource for me.

I plan to upgrade my 67 800 to hydraboost. I've about got all the info down to tear into it. The only issue I see is what hose/line goes where. Do you have a diagram of your line placement?

Did you run a cooler for more fluid?
Thanks again.

[Bill usn-1]

If you look at the pic in post 11 it shows the basic routing.
PS to booster to steering box.

The return originally T'd but later I added another return port on the PS pump resevior so each line has it's own connection.

I do run a cooler. The fluid gets warm and at altitude in the mountains was starting to get real hot.
I run valvoline PS fluid and a small midsize ford PS cooler behind the headlight.

[colorado_okie]

Bill,
Sent you a PM.

- Randy

[ANVA]

Is boosting the PS pump's pressure necessary and, if so, couldn't I just use the pump from the Astro van the system came from?

[Bill usn-1]

Boosting the pressure is not needed. If the pedal feel is not light enough you can always do it later.
The extra pressure made my steering feel very light. It helps on the trail when always turning at slow speed.
I'm sure you could use the van pump but depending on you scout you may be replacing all the lines with custom ones to hook it up.
The van is O-ring like the 1980 scout. It also uses a remote fill because it's mounted low on the engine. Not the standard canned ham.

['71 800B]

I just did the hydro boost in my 800. I used the scout II pump and the astro van HB. For the hoses, I used the astro van hoses, cut off the ends and used the scout ends. I flared them and have no leaks.
I still need to install the cooler and do the pressure mod but so far the brakes are awesome. the pedal feels soft, but I think it is due to the scout pedal being so much longer than the astro van pedal.

This is the best mod Ive done so far other than the power steering.

[Bill usn-1]

Feels good doesn't it.

Where's the pics.

Make sure you do a good MC bleed and the full brake bleed.

['71 800B]

Originally Posted by Bill usn-1

Feels good doesn't it.

Where's the pics.

Make sure you do a good MC bleed and the full brake bleed.

Feels awesome!!!

Didn't know brakes on a scout could work so well. I do have an issue with the pedal being very soft. I have bench bled the master over and over again. I have pushed a gallon ( yes a gallon ) of fluid out of all of the bleeders but I can still push the pedal to the floor fairly easy.
When traveling down the road, the brakes will put you through the windshield if you push more than about an inch and a half on the pedal. I don't mind how they work however the sponge thing bugs the crap out of me.

I am running a '78 grand marquis disc/drum master, astrovan booster, dana 60 front calipers and 11.5" rear 14 bolt drums with the stock proportioning valve. I cant see the proportioning valve being the problem because the brakes work perfect, no fade, no change at all while sitting at a red light. but you can push the pedal to the floor.

['71 800B]

this is what I did to mount it and leave enough room for the battery.

['71 800B]

another view....

[Bill usn-1]

Looks good.
I planned to just make a new flat plate to replace the stock one.
But that notch worked pretty good.

My pedal goes down further then normal but not to the floor.
It also changes when a MC with a different size piston is used.
The smaller piston moves less fluid on the stroke.

So a master cyl with a larger piston may help.
Have you verified the rod length. How much freeplay is there?

['71 800B]

I have verified the free play. I also made a piece to go inside the master to take up the space.

The bore size is the same as the astrovan m/c, I dont have that info in front of me at the moment. I may need to just replace the m/c with a 1 ton.

[doramider7]

Originally Posted by Bill usn-1

Here is a pic with them installed.

I purchase 1 new stock scout hose so both of them are the same.
It's a powercraft 70973.