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Update on Disk Brake conversion and rear end swap.

From: Jonny Milkshake
Email: teammilkshake@msn.com
Date: January 17, 2001

Comments

OK, Someone asked me for an update about a month ago, but I've been swamped over the holidays, and I thought it might be helpful to at least one more person if I replied on the Board instead of just a return email(sorry tom for the delay).

Here goes, I got the disk brake conversion from a 76 Plymouth Gran Fury. Parts include disk, caliper,spindle(removed as an entire assembly) booster and master cylinder as well as the proportioning valve. I also removed the front sway bar and will get into that installation later. I replaced all the bushings as well as the ball joints on the upper and lower arms( I got all the parst from my local NAPA), painted them and installed them back onto the front end. After rebuilding the calipers, turning the disks and repacking the bearings I put the spindles onto the arms. I noticed a 1 inch(or so)shorter difference in the spindle sizes from the originals but it didn't seem to make a difference in the long run. Now here is where I had to do slight modifications. The outer tie rod ends were too long, so I cut(with my handy-dandy saw-zall)1 and1/2 inchs of the threaded end. I ran the rod end through a die to make sure the threads would go into the adjustment pipe easily. Now when I say adjustment pipe, I mean the pipe that connects the outer tie ride to the inner tie rods. I also took 1 inch off the threaded pipe. I then bolted the tie rod assembly to the center link and the spindle. So far so good. The turn stops were kind of tricky and I ended up cutting off too much, so now if I turn to sharply, the tire rubs the inner fender. I would suggest cutting in 1/2 inch increments until you get to the desired turn-stop setting. I did have to go with 15 inch wheels, so those of you who wish to retain your stock 14 inch wheels and caps...forget it!

Now to the Master Cylinder/Booster. I decided NOT to use the booster at all, for two reasons. First the Booster/M.C. unit would require cutting and modifing the firewall and brake pedal, something I wasn't in the mood for. Second, wht M.C. bolts right up to the firewall, lickity-split. There is a pin that goes from the brake pedal directly into the M.C., this pin fits into a drilled out pocket. I had to increase the pocket size slightly. I used a drill to increase the hole. Now the pin fits perfectly and I didn't have to cut anything. With the M.C. bolted to the fire wall and the pedat attached to the M.C. I bent new lines for the Proportioning valve. Here is a handy bit of info, when removing the prop. valve from the donor car, make sure to take note how the lines run( rear, right side, left side, etc)as well as running and bending right, left and rear lines(VERY time consuming). I filled the M.C. bled the lines and ended up with a soft feel to the brakes, that would go away after pumping the pedal a few times, only to return after a couple of seconds. the soft feel was eliminated only after I replaced the rear end, which brings me to the next chapter in the story.

The Rear end was taken off a 73 Chrysler New Yorker. This is NOT the recommended rear end to use, but I forced to work. According to Daven Anderson a rear end from a Plymouth (65-73 I think) is the desired part to look for. The Chrysler is a little wider than the Plymouth. I had the spring pads moved an inch inward per side and rebuilt the brakes. Bolted them to the leaf springs and had the drive shaft modified to a larger universal joint(stock was slightly smaller) and whammo, the tires rubbed the sides of the wheel-well. Off comes the tires, out comes the sledgehammer, wham, wham and wham (careful no to dent the outer skin)and rubbing problem solved. If I find a Plymouth rear-end I WILL buy it and replace the one I have, though I am not completely unhappy with what I have. After spraying undercoating onto the wheel-well, you cannot even tell I clubbed it into submission. Suddenly the soft pedal feel is gone, due to the rear brake cylinders having a smaller diameter than the originals. Less diameter means less fluid to fill them, hence less brake pedal travel. I bypassed the e-brake connection....for now.

The sway bar was pretty easy. I had a friend weld a bracket in the shape of a box onto the front part of the frame.....you know what..It's really hard to describe the location of the brackets. The easiest way to find the location is to bolt ends to the bar that attaches to the lower control arm and frame(same bar you use for turn-stops)then measure to where the end links on the sway bar are located.

Good luck to all, and I hope this doesn't confuse anyone to much.

Jonny

 


Last changed: May 04, 2010