Manual Brake Conversion


Here's the details of my manual brake conversion using a kit from Master Power (part #MC1711K).  This kit isn't specifically made for the 78-up G-body.  I had to do some modifications to make it work, but you will see that below.   MP may have a kit for the 78-88 G-body, they were supposed to be working on it.

Click on pictures for larger image.


Click here to see how Pete swim did his conversion

Click here to see how Jim did his conversion



Here's the old power booster, about to be pulled out.   This is going to give me some much needed room to access the #5 and #7 plugs, not to mention improve the braking.  


Well, this is what it looks like with the old booster removed.  If you notice, the almost oval shape of the cutout from the factory to accommodate the installation of the manual brake master cylinder in the top 2 bolt holes.    

This is the gasket that was between the power booster and firewall.  I used this as a template to fabricate a block-off plate to cover the large hole left by the removal of the power brake booster.

Here's the block-off plate I fabbed from 1/8" aluminum plate.  It's not pretty, but it works. 

Click here to get a CAD mechanical drawing template of the block-off plate in PDF format

Here you see that I have cut out the insulation in the top of the hole in the firewall.   You'll see the color my car was painted from the factory where the gasket was located.  Yep, it was brown.


Here's my grungy old power booster and master cylinder.  It looked much better from the top, because it was painted on the top side....   If you look, you can see that it was obviously a junk yard piece because it has the infamous yellow parts marker writing on it.


Goodbye vacuum canister!


Here's what Master Power sent me.  A manual master cylinder, adjustable pushrod with clevis fitting, and rubber boot.


This picture shows why the Master Power kit is the easiest and SAFEST way to go.  If you will notice from this shot, the pushrod slides about 1.5" into the master cylinder.  It is drilled out large enough for the rod to fit inside of the pushrod seat.  There is NO WAY it can fall out.


Here's a shot of the pushrod seat, so you can see what I am talking about.  The pushrod slides about 1.5" into the machined seat. 


This shows how far it fits into the master cylinder.


This is a shot of the new MP manual brake master cylinder bolted to the firewall/adapter plate.  


This is what it looks like from the side.


Here's a shot from under the dash of the pedal assy. and the new master cylinder rubber boot sticking out.  It is in a direct line with the top hole in the pedal arm.   


Same as previous picture, just a different angle.  Man, it's not easy laying upside down taking pictures under the dash!


The pushrod in the MP kit is WAY too long.  It has to be cut.  To determine the length it needed to be, I got a piece of clothes hanger and inserted it into the master cylinder and marked it where it intersects the center of the hole on the pedal arm.  The rod is threaded on the other end to allow final adjustment of length. Unfortunately, my metal saw blade broke before I finished cutting the HARDENED (and I do mean hardened!) rod.  I've got new saw blades, so I should have everything buttoned up soon.  MORE TO COME!