This information does help, Doc. Thank you. I knew the disc master would not fit on the front of the drum booster because the flange widths were different. The tip about removing the check valve is noted. I still have not made my decision yet as to which system to use. I know I will have the disc front/drum rear, but may use a non- AMC braking system as far at the booster/master goes. I don't believe the Javelins and Matadors systems will work as the boosters are completely different visually, and I don't know if there would be enough hood clearance if used on the Gremlin. Soooooooooo....it may be a good choice for me to use a different set up all together. I was hoping that someone on this list had done a non-AMC booster/master set up and could give dimensions or cross-reference a model that works. I can't believe that I would be the first person to attempt such a swap, but maybe *I* will be the one to figure it out and then share the knowledge. Thanks again for your response, Doc. I appreciate your time. ~Lu~ --- In BaadAssGremlins@xxxxxxxxxxxxxxx, AMC74HORNET@xxxx wrote: > This is all from personal experience. The disc brake set up I got off a > 79 Concord sedan. I had no choice on a booster because it had non- power > brakes. I drove this car before I parted it out and I didn't care for > the pedal pressure required to stop it, but it did stop fine. Through > the AMX Files and from Frank Swygert from AIM I gathered this > information and used it on my yellow Hornet. A power brake master will > not fit on a drum brake booster. The main difference between masters is > that the disc master has a bigger reservoir for the front discs. This as > Frank put it to me makes it idiot proof. As the disc pads wear the fluid > level goes down. Not so on a drum brakes as they are adjusted > mechanically. The larger reservoir is so that between service the disc > master reservoir does not run out of fluid. The 79 Concord did not have > a proportioning valve neither did the 78 Concord with power disc brakes. > I used the stock 74 drum brake booster and master the was in the car. I > simply installed the disc's from the Concord with rebuilt calipers and > new pads and turned the rotors added new wheel bearings and seals and > rubber brake lines. You will have to remove the residual check valve in > the outlet port on a drum master for the front brakes or it will make > the pads drag slightly. Insert a sheet metal screw into the port and pop > out the flair flange and behind it is the check valve, remove it and > re-install the flair flange. On the proportioning valve I don't know if > you can use it on a drum brake booster/master. Since the Concord didn't > have one I did not have one. I was told I really didn't need it. But > being the pain I am I bought a Wilwood adjustable proportioning valve > and plumbed into the system. I set the bias at 50/50 to start with and > after making a couple of panic stops to see if I needed to change it, it > was fine at 50/50 which tells me I really didn't need it. All the > proportioning valve does is keep the rear wheels from locking up in a > panic stop. I was also told and found it to be true that the drum > booster is a single diaphragm and the disc is a duel diaphragm. The > result being using disc's with a drum booster requires a little more > pedal pressure, but not much. I can speak from experience on the > comparison as the orange car has the factory disc's. One thing on using > a drum master you should check the fluid level every 3 months or so. > This is my personal experience with the disc brake swap and I am happy > with the way the car now stops. Where I live there is a lot of hills and > the old drum set up used to fade real bad when it got hot. Sometimes it > was so bad I was afraid the car would not stop. I hope this helps. > "Doc" ------------------------ Yahoo! Groups Sponsor --------------------~--> Help save the life of a child. Support St. Jude Children's Research Hospital's 'Thanks & Giving.' http://us.click.yahoo.com/6iY7fA/5WnJAA/Y3ZIAA/YtqqlB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/BaadAssGremlins/ <*> To unsubscribe from this group, send an email to: BaadAssGremlins-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/