brake swap Q's

BAD87BUICK · 04-21-2005, 07:29 PM

I am about to change my 87 Powermaster out for a standard vacuum unit from a standard 87 regal 3.8. It looks to be a straight foward deal, is there anything specific i might need to know or watch out for? Thanks for answering, I know this must be the upteenth time someone has asked this

Steve Wood · 04-21-2005, 07:53 PM

it would be easier if gnttype was working as the instructions are there...

but, other than swapping out the brake pedal which can be a pain for the older generation who are no longer very flexible...it is pretty straight forward.

There is an adapter on the firewall that is used to mount the PM that must be removed and then the new mastercylinder/booster will mount straight on the firewall

Red Regal T · 04-22-2005, 07:18 AM

The first thing to do is to remove the powermaster system. This is accomplished by removing the 15mm nuts securing the PM to the firewall. They are located on each side of the brake pedal. There are four. Two on each side. Remove these, using a long extension, deep 15mm socket and ratchet. Unfasten the brake lines from the MC and disconnect the booster rod from the brake pedal. Unplug the electrical connections from the PM and remove the PM.

Next job is to swap out the PM brake pedal. In order to do this, you need to drop the saddle that the pedal is attached to. The four studs that held in your powermaster are the main fasteners that holds the saddle in place. After removing the PM the mounting bracket, there is till one more bolt holding the saddle in place. Looking directly at the brake pedal shaft, the bolt is threaded vertically up at the top of brake pedal. Only the head is visible. You should remove the brake light switch and the other switch above it that rest against the brake pedal shaft. Though they appear to be threaded in, they just pull out from the saddle. Take a long 3/8" extension with a 13mm socket. The bolt is about a half inch left of the pedal. Remove this bolt and the saddle will be free. You can remove the saddle completely and make sure the booster bolts align with the holes in the saddle. You may have to tap them with a hammer to align. This will make putting it in easier.

A word about the booster....the rod has a seal inside the booster and sometimes in installation or transit, it can somehow become cocked and cause a vacuum leak. Before bolting the booster in place, run a vacuum to the check valve from your engine, start the car and make sure the booster isn't leaking. I check them right before I ship them but this problem arises from time to time. You'll find it very difficult to push the rod in when there is no vacuum to it. When you start your motor, and apply vacuum, it's pretty easy to push in the rod.

OK, now with the new brake pedal installed, you can install the booster. Make sure the pin is in the recess in the frontcenter of the booster. It can fall out. It just slides in loosely. Install the booster into the firewall and through the saddle and install the 15mm nuts inside the firewall.

Next, you need to bleed the MC. Place it in a vice just tight enough to hold it in place. Use those cutoff lines I included. Use a tubing cutter to access open ends. Fit a hose tightly over each of the lines and run the other end of the hoses into the reservoir. Fill with clean brake fluid and then use a rod to push on the plunger of the MC. This will pump the air and old fluid into the reservoir. Keep pumping it until all air is removed and clean brake fluid is observed.

When this is done, you can attach the MC to the booster, reinstall the brake lines and you may be done. If there was no air in your brake lines before you attached the new MC, you will have a hard pedal. If there was air in your lines, your brake lite will probably be on, your brake pedal will be low and will pump up. This indicates air in your lines and you'll have to bleed all your wheels.

If you don't have a TTA vacuum block, you'll have to get your vacuum from the PCV vacuum hose. Purchase a 3/8" vacuum Tee from any parts store. Basically, cut into the pcv hose a couple inches above the pcv valve and install the T in that line. Run a 3/8 fuel hose for vacuum. Run it to the check valve on the booster. This will provide adequate vacuum for your vacuum brake system.

turbo nasty · 04-22-2005, 08:20 AM

awesome response ..thanx

Steve Wood · 04-22-2005, 08:32 AM

John, put a copy of those instructions in Mike's Tech Sticky at the top...nice job!

04-21-2005, 07:29 PM	#1 (permalink)
BAD87BUICK Registered User Join Date: Apr 2005 Posts: 118	brake swap Q's I am about to change my 87 Powermaster out for a standard vacuum unit from a standard 87 regal 3.8. It looks to be a straight foward deal, is there anything specific i might need to know or watch out for? Thanks for answering, I know this must be the upteenth time someone has asked this

04-21-2005, 07:53 PM	#2 (permalink)
Steve Wood Scam Detector Enabled Join Date: Sep 2000 Location: East of Eden, Texas Posts: 41,388	it would be easier if gnttype was working as the instructions are there... but, other than swapping out the brake pedal which can be a pain for the older generation who are no longer very flexible...it is pretty straight forward. There is an adapter on the firewall that is used to mount the PM that must be removed and then the new mastercylinder/booster will mount straight on the firewall __________________ ------------------ A proud member of Stonewallers Against Bogus Technology Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blindfolded fear. Thomas Jefferson . www.vortexbuicks-etc.com

04-22-2005, 07:18 AM	#3 (permalink)
Red Regal T BUICK LOVER Join Date: Sep 2000 Location: Zephyrhills, Fl USA Posts: 1,260	The first thing to do is to remove the powermaster system. This is accomplished by removing the 15mm nuts securing the PM to the firewall. They are located on each side of the brake pedal. There are four. Two on each side. Remove these, using a long extension, deep 15mm socket and ratchet. Unfasten the brake lines from the MC and disconnect the booster rod from the brake pedal. Unplug the electrical connections from the PM and remove the PM. Next job is to swap out the PM brake pedal. In order to do this, you need to drop the saddle that the pedal is attached to. The four studs that held in your powermaster are the main fasteners that holds the saddle in place. After removing the PM the mounting bracket, there is till one more bolt holding the saddle in place. Looking directly at the brake pedal shaft, the bolt is threaded vertically up at the top of brake pedal. Only the head is visible. You should remove the brake light switch and the other switch above it that rest against the brake pedal shaft. Though they appear to be threaded in, they just pull out from the saddle. Take a long 3/8" extension with a 13mm socket. The bolt is about a half inch left of the pedal. Remove this bolt and the saddle will be free. You can remove the saddle completely and make sure the booster bolts align with the holes in the saddle. You may have to tap them with a hammer to align. This will make putting it in easier. A word about the booster....the rod has a seal inside the booster and sometimes in installation or transit, it can somehow become cocked and cause a vacuum leak. Before bolting the booster in place, run a vacuum to the check valve from your engine, start the car and make sure the booster isn't leaking. I check them right before I ship them but this problem arises from time to time. You'll find it very difficult to push the rod in when there is no vacuum to it. When you start your motor, and apply vacuum, it's pretty easy to push in the rod. OK, now with the new brake pedal installed, you can install the booster. Make sure the pin is in the recess in the frontcenter of the booster. It can fall out. It just slides in loosely. Install the booster into the firewall and through the saddle and install the 15mm nuts inside the firewall. Next, you need to bleed the MC. Place it in a vice just tight enough to hold it in place. Use those cutoff lines I included. Use a tubing cutter to access open ends. Fit a hose tightly over each of the lines and run the other end of the hoses into the reservoir. Fill with clean brake fluid and then use a rod to push on the plunger of the MC. This will pump the air and old fluid into the reservoir. Keep pumping it until all air is removed and clean brake fluid is observed. When this is done, you can attach the MC to the booster, reinstall the brake lines and you may be done. If there was no air in your brake lines before you attached the new MC, you will have a hard pedal. If there was air in your lines, your brake lite will probably be on, your brake pedal will be low and will pump up. This indicates air in your lines and you'll have to bleed all your wheels. If you don't have a TTA vacuum block, you'll have to get your vacuum from the PCV vacuum hose. Purchase a 3/8" vacuum Tee from any parts store. Basically, cut into the pcv hose a couple inches above the pcv valve and install the T in that line. Run a 3/8 fuel hose for vacuum. Run it to the check valve on the booster. This will provide adequate vacuum for your vacuum brake system. __________________ John DiCarlo GSCA #52 87 RED REGAL T 87 DARK RED T 87 GRAND NATIONAL MANY PHOTOS HERE

04-22-2005, 08:20 AM	#4 (permalink)
turbo nasty Boost Sux my Wallet Join Date: Aug 2003 Location: Mississippi Gulf Coast area Posts: 1,216	awesome response ..thanx __________________ 87 GN (3480lbs w/me & 1/2 tank) GT3255E, ESP FMIC, Razors Alky, Turbosaver, TA Headers, THDP w/test, ATR crossflow, Gen2, Ext G, LT1 MAF 38's, Extrem Auto Stg2 trans, Pats 10" 2.6k l/u, QA1 front and rear, UMI Ups (adj) and lows, HR bar, moser axles, Eaton, MT DR's. 2003 G35 Coupe Blk on BLk, JDM Clears, 18's, Prem PKG, Lthr, Bose....wifes car 2005 Harleys : Wide Glide & Duece ...Mucho Bling

04-22-2005, 08:32 AM	#5 (permalink)
Steve Wood Scam Detector Enabled Join Date: Sep 2000 Location: East of Eden, Texas Posts: 41,388	John, put a copy of those instructions in Mike's Tech Sticky at the top...nice job! __________________ ------------------ A proud member of Stonewallers Against Bogus Technology Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blindfolded fear. Thomas Jefferson . www.vortexbuicks-etc.com

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