Power master to vacuum conversion question.

[Vertigo107]

Quick question about the brake pedal when setting up the EB kit.. How do I know where to drill the new hole for the booster linkage pin? There's not a template or any paperwork that came with the kit. Thanks!

 

[626gn]

Quick question about the brake pedal when setting up the EB kit.. How do I know where to drill the new hole for the booster linkage pin? There's not a template or any paperwork that came with the kit. Thanks!

Measure 1-1/4" down (center to center) and closer to the edge. That is the new location for the pin. Notice the edge of the pin is now parallel with the large flange on the Powermaster pin.

 

[Vertigo107]

Measure 1-1/4" down (center to center) and closer to the edge. That is the new location for the pin. Notice the edge of the pin is now parallel with the large flange on the Powermaster pin.

Thanks for that info!

 

[bumperjack]

Hi,
I've decided that my power master brake system is getting too expensive and dangerous. I want to convert it to the vacuum system. I see Gbodyparts and Kirban sells the kits. Kirban's is much more expensive. Is it better? Anyone else these sells these kits? Thanks.

 

[Chuck Leeper]

I'd look elsewhere.

 

[grandnat_6]

If you look on the first page of this thread you will see a link to ebay. Earl Brown. He sometimes has them. Was going to buy one but someone beat me to it. I ended up purchasing my own booster, and master cylinder through advance auto parts. Found a NOS vacuum filter on ebay. and waiting for NAPA to get my 11/32" vacuum hose in. Got a brass Tee from Autozone. Friend is using his connections to get me a brake pedal from a vacuum booster G body.
BTW; Anyone know if there is a certain direction the filter needs to be plumbed? There is a straight connection and a 90 degree connection....

 

[1986 Buick GX1]

If you look on the first page of this thread you will see a link to ebay. Earl Brown. He sometimes has them. Was going to buy one but someone beat me to it. I ended up purchasing my own booster, and master cylinder through advance auto parts. Found a NOS vacuum filter on ebay. and waiting for NAPA to get my 11/32" vacuum hose in. Got a brass Tee from Autozone. Friend is using his connections to get me a brake pedal from a vacuum booster G body.
BTW; Anyone know if there is a certain direction the filter needs to be plumbed? There is a straight connection and a 90 degree connection....

Refer to post #19 on the filter purpose. It’s not needed for our setup. Makes it cleaner without one.

 

[grandnat_6]

That's what I get for waiting around to make a decision.

 

[earlbrown]

Quick question about the brake pedal when setting up the EB kit.. How do I know where to drill the new hole for the booster linkage pin? There's not a template or any paperwork that came with the kit. Thanks!

Put your booster on the firewall and pull your pedal back against the brake light switch. Scribe the location of the eyelet on your pedal arm.

That way the pedal ends up exactly where you foot expects it to be on your exact car.
The build quality of GM in the 80s isn't considered ''exact'' back then, so a template won't be dead nuts.

This method will get you back on the road without having to mess with your muscle memory.

 

[grandnat_6]

Got the booster and master cylinder installed.
From previous post and pictures, I notice a bit of install differences. I had to drop a harness connector and leave it hang. Had to pull a bit to get the speedometer cable hooked back up. It’s a bit taught. The ground on the firewall from the harness that goes across I had to relocate to one of the fender screws above the relays. My 11/32” vacuum hose does not fit over the vacuum block port I purchased from Gbodyparts.com. Any comments or suggestions?

 

['87 Turbo "T"]

Got the booster and master cylinder installed.
From previous post and pictures, I notice a bit of install differences. I had to drop a harness connector and leave it hang. Had to pull a bit to get the speedometer cable hooked back up. It’s a bit taught. The ground on the firewall from the harness that goes across I had to relocate to one of the fender screws above the relays. My 11/32” vacuum hose does not fit over the vacuum block port I purchased from Gbodyparts.com. Any comments or suggestions?

The old PM harness is fine. I would just take some tape & cover it up. I'm confused at why you had to move the ground. The vacuum swap wouldn't affect that ground at all. Worse comes to worse just get a bigger vacuum hose if needed.

Personally I deleted the block & moved my vacuum ports to the back of my intake. Makes for a cleaner look. I get it though, that's a bit of a bigger project.

 

['87 Turbo "T"]

I also got a bug up my ass this winter & got myself a buss bar if you will, & took most of my interior grounds(gauges, flashers, PLX wideband, Powerlogger, & some other items), the body to trans ground, TR6 ground, & the black ground all to one point with a 10ga wire that goes back to the battery.

When the new motor is done that silver ground will go to the ignition bracket. Maybe this won’t help at all but in my mind ya can’t have too many grounds & the body to me isn’t the best ground location.

Sorry about the thread hijack.

 

[grandnat_6]

I was able to finally finish this up last month. The vacuum block needed a 15/32" hose and the brake booster needed an 11/32"' hose. The 11/32" hose fits inside the 15/32" hose, so I cut a small piece off put it over the brake booster and then slide the 15/32" hose over and clamped it. Working good.

 

[TIMINATOR]

Till you have a backfire.....
Your life, and those in front of you.
This is what I did, it works with stock or removed egr boss. I did mine when I ported the manifold, which is a good idea at any power level by my thoughts. One of my customers WELDED HIS ON THE CAR! I don't recommend that!
After welding both the bosses shut, he drilled and tapped the vacuum hole, using a shop vac to get the chips out! But to his credit, he also had a pal blow shop air into the opened T body while drilling and tapping. He removed all the injectors on the drivers side, and duck taped everything closed.
I think removing the manifold, then porting it and removing the EGR boss, and welding and drilling for the vacuum, is a better plan.
TIMINATOR

 

[granitestategn]

So when I did my vacuum brake conversion many years ago I just went to a junkyard and pulled the brake pedal out of a Monte Carlo and bought a booster and MC for a Monte and installed them. AM I missing something or are they just hard to find? I like Earl's design but it wasn't around when I did mine. Earl's design does save you from hanging upside down under the dash of a junked car, so there's that.

 

[earlbrown]

Finding 80's cars like Monte Carslows in the junkyard is damn near impossible now. And if you do find one, your Buick will end up with Chevy stank bolted under the dash.
That arrangement I came up with actually turned out better than expected. When Advance Auto quit warranting my powermaster, I tried about 10 different things to make a safe, workmanlike, and robust arrangement to get my car stopping again. I had all kinds of crap with shoulder bolts, brass bushings, small bearings, all kinds of crap.
At the end I got lucky and found one supplier that had small forged steel clevis pins that worked out really well. Simple, strong, and to the point.
Way less Rube Goldberg that the bearings and spacers and shit I was working on! LOL