Vacuum brake conversion - who has done it?

[84BuickGNYorkPA]

Banning,

You will love the vacuum brakes, as long as your motor makes good vacuum. With a fresh motor you shouldn't have any issues. When I got my car from Jack with the motor/tranny conversion, only needed the big toe to make the car stop fast. You may want to get some more feedback, about the vacuum of a engine with your cam and heads... just to be sure, before spending the $$

Chuck

[NJBuickRacer]

I've converted a few back to powermasters from vacuum.

[1970gsx]

Originally Posted by NJBuickRacer

I've converted a few back to powermasters from vacuum.

See, I'm not the only one not satisfied with the vacuum setup.

[jdodman]

I will start with, I do not know jack about vacuum brakes, except what I read here on the board. That said, when I purchased my latest GN (2002) the seller had just spent $660.00 plus dollars, to restore the stock brake set up. All was brand spanking new. Even the brake lines...

With the exception of the occasional Red Brake Light illumination on my dash from the line lock set up (I have bled them until I was bleading) I have not had any concerns. Brakes are currently dead on for the age of the engineering. But reading these posts (and Orlando's), I have concerns..

Can someone that has gone from vacuum brakes, back to stock tell us why...
I only see that there is the occasional scare when the motor is at full throttle.
Are there other reasons ?? What am I missing ??

[J Banning]

Originally Posted by jdodman

...Can someone that has gone from vacuum brakes, back to stock tell us why...
I only see that there is the occasional scare when the motor is at full throttle.
Are there other reasons ?? What am I missing ??

+1

[GrndNatnl]

Based on a few situations I've been in personally....

With vacuum brakes, if the car stalls out (and these cars do that crazy sh!t sometimes..) for any reason, or at highway speed, or at the track, you have about one pump or a couple seconds of braking power. After that the pedal turns to stone.

I like the fact that if the ignition is on, and the engine is off, I still have brakes. It's happened to me before when my car kept popping fuses while I was going down the highway during some electrical woes. Also, back before that I had an issue with my old injectors and chip combo where for some reason after getting off the throttle immediately after a WOT run, the car would just stall out. But I still had brakes!

Even if the Powermaster craps out, you still have a better pedal feel then vacuum when theres no vacuum. It's not easy, but you still have manual brakes to some degree. A lot more then vac with no vac.

Collin drove around with his PM dead for quite a while. He got tired of seeing the Brake light illuminated and removed the bulb if I remember correctly. And he was still even able to hold boost on them somehow.. which was interesting.

[Slow91z]

Actually mine is still dead.

My opinion is without the power assist the car is basically a manual brake car right?? Since most of us racers have installed manual s10 wheel cylinders it makes it bearable for us when the powermaster dies.

I'm thinking about installing the circle track front calipers U.S. Brake Aluminum Brake Calipers - JEGS

And a manual master cylinder...Drop a few pounds and I think I'll have better braking then I do now.

BTW for all you racers out there I can hold 5-8 psi on the foot brake still...Don't get me wrong I am using some serious leg power to do it.

I can lock up the rear tires but it ain't all that easy.

Oh and my 5'0" aunt drove my car and did fine with it to you pansies!!!

[gnetic86]

Originally Posted by GrndNatnl

Even if the Powermaster craps out, you still have a better pedal feel then vacuum when theres no vacuum. It's not easy, but you still have manual brakes to some degree. A lot more then vac with no vac.

As far as Powermaster failure experiences, I had to STAND on the brake pedal, and roll UP a ramp to stop the car from the expressway, and I was in bumper to bumper traffic so I wasn't going that fast. (Merging over was definitely fun)

It scared me enough that at some point I'm considering putting a back up switch in line with the fuse, so that if the fuse ever blows...hit the switch to bypass it.

That said my Powermaster works GREAT when it comes to really stopping in an emergency, at least ever since I put the new pump on.

[J Banning]

Originally Posted by gnetic86

As far as Powermaster failure experiences, I had to STAND on the brake pedal, and roll UP a ramp to stop the car from the expressway, and I was in bumper to bumper traffic so I wasn't going that fast. (Merging over was definitely fun)

That is EXACTLY what I don't want to experience when I hit the brakes after making a pass down the track! And that's why I brought this topic up, I want to know what my options are, and what are the pluses and minuses of each.

I have two friends who are running full manual brakes, and they work well... on the track - neither are tagged for the street. That option is still open in my mind. Need to do more research though.

-Bronson.

[GrndNatnl]

My dad's 442 is full manual brakes. Takes a little leg muscle, but it stops great. However, he did install 4-piston Wilwood front brakes during this past winter. I think drilled & slotted rotors as well. But I drove it before all that. And it's tagged for the street. It's actually got Florida tags now, heh. No more inspection.. must be nice.

[Madboost]

B:

Manual might be an option... As long as you don't mind pushing pretty hard they work great, have great pedal feel, and are pretty cheap to go to. If it stalls there is no difference! Good for pushing the car around without a motor or trans.

[GrndNatnl]

I think I agree with Ted on that one.

[NJBuickRacer]

Originally Posted by jdodman

Can someone that has gone from vacuum brakes, back to stock tell us why...
I only see that there is the occasional scare when the motor is at full throttle.
Are there other reasons ?? What am I missing ??

It was on customers' cars when I worked at Dynotech, several complained that they didn't like the pedal feel compared to the powermaster. A few friends didn't like the fact that they used all their vacuum up holding boost at the line, then if they popped a head gasket or had another problem that shut the engine down there was no vacuum for the brakes at all. I prefer manual over the powermaster, and vacuum as a last resort.

[gnetic86]

I spotted a new looking vacuum booster at the 'yard today.

[87granny]

Well mine feel better now after some new fear shoes and axle seals that does not leak. But what do i know i havent driven one with a Pm