Powermaster Issues

[RezVek]

So I placed my order with Earl for his Vac kit. Seems like a great guy, very helpful and knowledgeable.

 

[RezVek]

Thanks to all that responded here! I am likely to need more of you expertise once I start tearing into the PM.

 

[RezVek]

1 other thing, I may as well ask…. i’m trying to visualize why a new hole is needed in the pedal arm, or a new pedal. It seems that the new booster would use the same firewall hole as the PM and mounts to the same bolts. How doesn’t it use the same spot on the pedal? Is it because there is no exact replacement and the new booster connection thru the firewall some how just sits a little bit lower or higher? I like to try to understand things before I do them, instead of just blindly doing.

 

[626gn]

1 other thing, I may as well ask…. i’m trying to visualize why a new hole is needed in the pedal arm, or a new pedal. It seems that the new booster would use the same firewall hole as the PM and mounts to the same bolts. How doesn’t it use the same spot on the pedal? Is it because there is no exact replacement and the new booster connection thru the firewall some how just sits a little bit lower or higher? I like to try to understand things before I do them, instead of just blindly doing.

There is an adapter plate that converts the 4 bolt mount to a two bolt mount needed for the powermaster that looks like this

This plate is angled such that it causes the pin location to be higher on the pedal for a powermaster setup. The conversion to vacuum eliminates this plate thus pin location needs to change accordingly.

 

[RezVek]

There is an adapter plate that converts the 4 bolt mount to a two bolt mount needed for the powermaster that looks like this
View attachment 393582
This plate is angled such that it causes the pin location to be higher on the pedal for a powermaster setup. The conversion to vacuum eliminates this plate thus pin location needs to change accordingly.

Aaahhh yes I knew about the plate but never teallt thought about what it was for….. so this plate was like an adapter to use the PM, so they needed a different pedal. Now converting to vacuum, we are going to the original engineer plan for non-turbo models, so we remove the plate and change the pedal back, or drill a hole. That seem about right?

 

[626gn]

Thanks to all that responded here! I am likely to need more of you expertise once I start tearing into the PM.

It's a straight forward procedure. I poached the following instructions off another vendor website. I'm sure I didn't follow it word for word but did find some of the tips useful.

PROCEDURE

Place the vehicle in a suitable work area, you will have to raise up your car to bleed the brakes, so do this on a level, safe area.

It takes about 1.5 hours to remove the old pedal and power master.

1. Remove the Positive + Red battery cable! ! ! ! !

2. Using the turkey baster, pump, or short piece of hose to drain as much of the old brake fluid out of the power master as you can. It will keep the inside of your turbo Buick and the paint looking better, longer.

3. Removal of the brake pedal is tricky.

a. Lay the driver's seat down in recline mode.

b. Your head will rest on the floor looking up under the dash, try to keep your feet off the headliner! Using needle nose, duckbills or pliers, remove the clip that retains the slug master piston shaft to the pedal

c. Use of an air ratchet makes it easy to loosen the pedal pivot bolt, use an 11/16" short socket.

d. Use a 5/8 open-end the other end from turning.

e. When the pedal comes out, there will be a number of parts to locate. The bolt and nut, two plastic bearing inserts as well as a piece of tubing that fits between the plastic bearing inserts and the pedal assembly.

4. you may have to disconnect the speedometer cable at the joint right under the power master.

5. After the powermaster, there is an adapter that must also be removed from the firewall. It has four mounting nuts (15mm) that must be removed from inside, way up under the dash. Use a 15mm deep socket and a 12" extension and use a flexible joint (3/8 drive). With air tools, about 3-4 minutes and you will have all of them on the floor.

6. Dress all of the wires, hoses etc away from the opening to install the new Vacuum non-turbo master cylinder and booster.

7. The booster mounting nuts must be re-installed from the inside with the same tools used to remove in step 2.

8. There was no requirement for any adapters etc..

9. Don't forget to re-connect the speedometer cable.

10. Put the pedal with the new stud in the same manner that the original one came out. (Hint) Put the bushing and plastic bearings in the brake pedal assembly. Wrap a piece of masking tape around the pedal and over the end pieces to keep it all together so the loose bushings will not fall out when you try to maneuver it into place it up under the dash. BEFORE you attempt to re-install, take your knife and pierce the tape through the center of the bushing holes and carefully slide the bolt through the tape. If you do it right, you will have tiny pieces of tape holding the bushings in while not obstructing the bolt hole. This makes installing the pedal a piece of cake.

11. Put the Push ROD from the booster onto the stud on the newly installed pedal. Re-install the clip.

12. Connect up the vacuum source. Your new vacuum Block ( TTA style ) It has been suggested that you use small hose clamps (#4 I think) to prevent engine boost from blowing off the lines. I recommend you change the PVC valve while you are at it.

13. Take appropriate action with your brake fluid, refill, bleed etc if required.

 

[RezVek]

It's a straight forward procedure. I poached the following instructions off another vendor website. I'm sure I didn't follow it word for word but did find some of the tips useful.

PROCEDURE

Place the vehicle in a suitable work area, you will have to raise up your car to bleed the brakes, so do this on a level, safe area.

It takes about 1.5 hours to remove the old pedal and power master.

1. Remove the Positive + Red battery cable! ! ! ! !

2. Using the turkey baster, pump, or short piece of hose to drain as much of the old brake fluid out of the power master as you can. It will keep the inside of your turbo Buick and the paint looking better, longer.

3. Removal of the brake pedal is tricky.

a. Lay the driver's seat down in recline mode.

b. Your head will rest on the floor looking up under the dash, try to keep your feet off the headliner! Using needle nose, duckbills or pliers, remove the clip that retains the slug master piston shaft to the pedal

c. Use of an air ratchet makes it easy to loosen the pedal pivot bolt, use an 11/16" short socket.

d. Use a 5/8 open-end the other end from turning.

e. When the pedal comes out, there will be a number of parts to locate. The bolt and nut, two plastic bearing inserts as well as a piece of tubing that fits between the plastic bearing inserts and the pedal assembly.

4. you may have to disconnect the speedometer cable at the joint right under the power master.

5. After the powermaster, there is an adapter that must also be removed from the firewall. It has four mounting nuts (15mm) that must be removed from inside, way up under the dash. Use a 15mm deep socket and a 12" extension and use a flexible joint (3/8 drive). With air tools, about 3-4 minutes and you will have all of them on the floor.

6. Dress all of the wires, hoses etc away from the opening to install the new Vacuum non-turbo master cylinder and booster.

7. The booster mounting nuts must be re-installed from the inside with the same tools used to remove in step 2.

8. There was no requirement for any adapters etc..

9. Don't forget to re-connect the speedometer cable.

10. Put the pedal with the new stud in the same manner that the original one came out. (Hint) Put the bushing and plastic bearings in the brake pedal assembly. Wrap a piece of masking tape around the pedal and over the end pieces to keep it all together so the loose bushings will not fall out when you try to maneuver it into place it up under the dash. BEFORE you attempt to re-install, take your knife and pierce the tape through the center of the bushing holes and carefully slide the bolt through the tape. If you do it right, you will have tiny pieces of tape holding the bushings in while not obstructing the bolt hole. This makes installing the pedal a piece of cake.

11. Put the Push ROD from the booster onto the stud on the newly installed pedal. Re-install the clip.

12. Connect up the vacuum source. Your new vacuum Block ( TTA style ) It has been suggested that you use small hose clamps (#4 I think) to prevent engine boost from blowing off the lines. I recommend you change the PVC valve while you are at it.

13. Take appropriate action with your brake fluid, refill, bleed etc if required.

Thanks much!

 

[RezVek]

I got my kit but it didn’t come with the line check valve (pictured below) and I can’t find anywhere to purchase one(seems discontinued). Anyone know if there is a replacement part I should search for? It also seems that the new booster has a check valve already on it so maybe the below unit is no longer required?

 

[LANDAU LIMITED]

That's a vapor canister to stop gas vapors from damaging the booster. I threw mine out when it blew apart from boost.

 

[RezVek]

Oh I see, so I can carry on without it? Or is there a more dependable filter to use?

 

[LANDAU LIMITED]

Yes, not needed.

 

[RezVek]

Yes, not needed.

I will run without! Thanks for the response.

 

[RezVek]

Got the PM out ok, but i’m having issues getting the new booster thru the firewall and thru the brake pedal bracket. Seems it has slid down or something but I can’t push it up. I was advised to leave the pedal in so when I put the new booster in, I can make the pedal for the new pin. Not sure if this is causing me an issue? Should I be pulling the whole bracket/pedal assembly? is there another bolt other than the 4 I already removed for the PM bracket?

 

[LANDAU LIMITED]

 

[RezVek]

View attachment 393928

View attachment 393928

ok I can pull that bolt but I was told just to remove the PM and put in the new booster and then mark the pedal for the new bolt(instead of measuring to hit the exact position. I mean I can pull it and then do the measure and drill but I was hoping the “easy” way. Looks like I will just pull, measure, and drill. I just hope it will line up cuz for some reason it isn’t atm.

 

[RezVek]

Got the pedal modified and back in. Looks like the brake light switch no longer hits the pedal. I have not investigated too much on it but any tips on how to adjust that?

Also, I was told I had to move the brake line that was by the firewall to the port closer to the front of the car and move the one that was closer to the front to the one closer to the firewall. When I test fit, they only fit one port each (to loose or too big to go in the other). Since I was told
this by the seller, do I need some fittings to make them fit? Or just put them where they fit?

 

[RezVek]

For the brake lights, it looks like the whole assembly just turns to make the required adjustment. I got the bit white plug off the back just fine but I can’t seem to get the the little black one out.

 

[GN86Rome]

Can I shift gears for a moment hello fellows I’m about to start bleeding process of the power brake system. Had to repair brake line left side front to back. Rear brake job to include wheel cylinders. Changed both front calipers as well. With KO no brake light pump runs when when I apply the brakes. So to bleed this system any different from regular brake system?

 

[KC87]

Can I shift gears for a moment hello fellows I’m about to start bleeding process of the power brake system. Had to repair brake line left side front to back. Rear brake job to include wheel cylinders. Changed both front calipers as well. With KO no brake light pump runs when when I apply the brakes. So to bleed this system any different from regular brake system?

Depressurize the accumulator bulb, leave the key off and bleed like any other.

 

[GN86Rome]

Thanks for responding KC87. I’ll give that a shot tomorrow, will keep you a breast of my progress.