G-body Manual brakes

[Turbo Loyd]

Has anybody converted over to manual brakes using the Powermaster petal assembly, a 1 inch bore G-body vacuum style master cylinder directly bolted to the Powermaster brake adapter ring that bolts to the fire wall.

The only part that would have to be fabricated is the push rod from an S10 pickup that comes with the ring that holds it in place.

Powermaster left and vacuum right. The powermaster pin placement is at the same spot as a manual brake pin would be located.

Vacuum MC attached to powermaster adapter ring

Stock S10 brake pushrod

Pushrod shortened

This seems like a relatively simple way to open some space up by eliminating the vacuum booster or getting rid of a Powermaster with problems.

Any experiences to relate

 

[DR BOOST]

i used the billet wilwood 1.125 master and the powermaster adapter. ill let you know in a week how it works.


btw where did you get the rod end from?

 

[Scott Atk]

I did it the way you described. Although i used an S-10 master cylinder, probably the same as G body. I think it's 15/16" bore.
Do a search on manual brakes. THere's lots of info, complete with pictures.

 

[jimbow]

I'm thinking of doing this. How's the pedal feel? What reservoir did you use?

 

[jimbow]

Where are you guys getting the pushrod from? I need all the info please? How does this compare to the mopar MS that some people use?

 

[Scott Atk]

Here's the hot ticket. Go to the junkyard and take the vacuum booster out of a random G-body. Before you ever leave the yard, take a screwdriver and hammer, and break the plastic area where the pushrod goes into the booster. Once you get the pushrod out, it's the perfect length for a PM pedal and GM manual MC. I might have drilled the engagement hole in the MC a little deeper to ensure it stays in but I don't remember for sure. You can also build an adjustable pushrod out of a long bolt and a turnbuckle similar to what's pictured in this thread.
The beauty of this setup is you can use the adapter that comes stock on your turbo buick. If you go with a Mopar or Wilwood, you'll need a billet adapter.
Search for manual brakes or my name. I've put up a bunch of info and pics.

 

[jimbow]

I'm having trouble getting the pushrod, none of the junkyards around me have any g body's. Does anyone have one they want to sell?

 

[jimbow]

I just finished my install tonight. I used an 85 s10 MC, mid 80s g body brake pushrod. It's very simple and bolts right up!!! The only thing I had to do was enlarge the hole in the pushrod. I highly recommend doing this!!!! I love not have a powermaster. It looks much better and I love the brake feel aswell.

 

[Scott Atk]

good deal... where did you find that pushrod?

 

[jimbow]

The junkyard. Lol. They had about 10 g body's. Thanks for the help Scott.

 

[Scott Atk]

No sweat... glad to help. Did you reuse the rubber cup thingy that goes with the original powermater firewall adapter? Hopefullly so, it helps with pushrod retention. You can't be too careful, if the pushrod becomes disengaged from the MC it will get ugly quick.

 

[jimbow]

Yes I did.