Hydroboost Install Pics

[ThisGuyUKnow]

I decided that even though the Yj brake booster is light years ahead of my old CJ one that I was greedier for a little more brake power. So instead of doing like a resposible person would and focus on upgrading the braking components at the wheels I grabbed a HB unit from a 91 astro van at the JY. Google searches of " hydroboost conversion" really didnt pull up alot of useful info. it was mostly stuff about the vanco kits. I kinda filled in the blanks with some help from other threads and with some guidance for Elliot on IFSJA.org.

The Yj vac booster bracket just needed the holes elongated a little and the 3.5x3.5 mount bracket from the 91 astro fit well. I was also able to reuse the old brake rod boot from the vac booster so no worries on holes in the firewall.

I miscalculated the rod length and ended up a tad short so I had to get creative with a second coupler and a stud. I had to cut the second coupler shorter but after some swearing everything lines up and the articulation seems good. The eyelet turned out to be the same size as the peg on the YJ brake pedal so that was a nice little x-mas gift from the jeep gods.

As suggested by Elliot I used a 79 j10/FSJ MC. Ideally I would want to use an astro MC however I had the FSJ one already and a new astro unit was like 70 bucks at the parts store. The FSJ MC is like .25 inches smaller on the bore size from the astro. I did go look at the astro MC at the parts store and the threads for the brake lines are the exact same size as the old cj lines so that is fun. WIth the fsj mc I had to swap the lines sides but bolted up fine.

havent had a chance to plumb the lines or bleed the brakes yet so will report on the braking next week after the dust settles from xmas.

 

[ThisGuyUKnow]

More pics



Its all plumbed and and been bled. A quick Parts list:
1991 astro Hydrobooster
1979 J10 MC
3/8x16 coupler(2x)- Carquest is the only parts house I think you'll find this in stock
3/8x16 die
3/8 ps return line
3/8 barbed brass t-section
PS to PS box line from 1993 wrangler(I have a 4.0 PS pump in my application)
HB to PS box line from a 86 K30 blazer
Ps return hose end fitting from a 1988 GW(got it at oreillys)
In line PS filter(got it at Oreillys, its the black thing that looks like a fuel filter in the first pic of the this post)

The wrangler PS hose screwed straight into the feed port on the HB unit no problem. Same with the k30 hose to the box. I orignally got a plastic t section from oreillys that was for radiator lines but I learned when I lost PS and brakes around the corner of my house that plastic is not a good idea.

I have to say the stopping difference is amazing. I barely have to tap the brakes for full stopping power. Its pretty sweet. I didn't try to lock the brakes up because its icy out but I am pretty sure I could if I wanted it. Either way I am glad I finally got around to doing this.

 

[ThisGuyUKnow]

I have some miles on this setup and just wanted to say that it is still working well. I had to chase down some leaks which turned out that one of the o rings didn't sit right. I wish I had did this first over going to a yj brake booster.

 

[ThisGuyUKnow]

I did this swap again on my newest cj. I still used a yj booster bracket but this time I discovered that the stock CJ7 brake mc fit and worked just fine with the hydra boost.

 

[Scooter402]

I am working on this with my CJ, too. I already have the HB unit installed, I just don't have it plumbed except for the brake lines. Mine (I believe, anyway -- got it off eBay) is from a bread van. Not sure if the MC will be too big of a bore, but it seems to work decently without the HB lines hooked up.

My question is about the hose routing. I always thought that the lines were supposed to go from the pump to the HB in, HB out to PS box, then both return lines from the PS box and HB unit tee in together back to the reservoir? If I am understanding correctly, you have yours opposite of that. Not saying you are wrong, but I am just curious.

 

[ThisGuyUKnow]

My question is about the hose routing. I always thought that the lines were supposed to go from the pump to the HB in, HB out to PS box, then both return lines from the PS box and HB unit tee in together back to the reservoir? If I am understanding correctly, you have yours opposite of that. Not saying you are wrong, but I am just curious.

That is exactly how mine is plumbed.... I put an inline filter in the system though.

Out of curiosity, what did you do for the booster to the firewall bracket.

 

[Bent]

I can't believe I didn't hear of this sooner! I just finished my power steering up grade, and this is next. How do the brakes feel with the engine off? Like vac assist with the engine off or like a non assist MC? I have stalled it before, once.

 

[ThisGuyUKnow]

I can't believe I didn't hear of this sooner! I just finished my power steering up grade, and this is next. How do the brakes feel with the engine off? Like vac assist with the engine off or like a non assist MC? I have stalled it before, once.

The gold cylinder on the booster stores pressure for one or two brakes I'm stalled situations.

 

[mtnwhlr]

How do the brakes feel with the engine off? Like vac assist with the engine off or like a non assist MC? I have stalled it before, once.

Yes with the engine off you have no assist.

 

[ThisGuyUKnow]

Yes with the engine off you have no assist.

If the hydra is working properly, you will get assist for one or maybe two brakes immediately after the engine is shut off. THat is what that gold cylinder is for, it holds a residual pressure, enough to brake if the engine is stalled.

 

[Scooter402]

That is exactly how mine is plumbed.... I put an inline filter in the system though.

Out of curiosity, what did you do for the booster to the firewall bracket.

You know, I don't really recall. I might just have to go look next time I'm in the garage. I may have oblonged a couple holes, but that's about it. It pretty much bolted right up. Odd thing was it seems that the pushrod was just the right length. But, I haven't driven it on the street with the booster hosed up, so I can't really attest to that just yet I suppose.

 

[GatorBate]

I ran across this Thread a few weeks back and it got me thinking... I have two 80 something suburbans with Hydroboost out in the field. So I pulled one out, cleaned it up, put new seals and O-rings in it and when to work building a mounting bracket out of some 10ga steel and 3" square tubing.

I had to cut about 3" inches out of the push rod and after messing with it all weekend I finely turned the key and tried it out.

I put the dog on the floor twice before I got out of the driveway. Oh my, I have brakes now! Thank Guy for the idea and write up.

Rear disk brake kit is on order. Don't know that I need it now, oh well

 

[GARGOYLEJEEPER]

Nice thread, I should have removed more `80 Wagononeer parts!