4x4 - Home

Rear Disc Brake Conversion



After both rear calipers were on and the brake lines were attached, we pulled the combination/proportioning valve and removed the small black o-ring from the stem and then buttoned it back up.  Be careful when removing the threaded cap, since there is a spring inside which keeps it under tension.  If you have a friend near by, solicit some help as it is much easier to reassemble this with two people working on it.

NOTE:  As of February, 2003, I installed a new ZJ combination valve in place of the TJ's valve.  The details can be seen here

The other item we had to take care of was the installation of the new Performance Friction pads for the front calipers.  These pads, available from AutoZone, are a necessary part of this conversion.  The Performance Friction pads improve the front calipers performance.  It seems to keep the bias between the front and rear calipers balanced out so that the installed changes still work well together.  A quick brake bleeding session got the air out of the lines.

The last thing to do before picking up the tools was to break in the Performance Friction pads.  This consists of a series (about 10) of rapid braking stops from about 40 MPH down to a full stop.  After the first round of ten, drive around and let the rotors cool down a bit.  After 5 minutes or so of no or low braking effort, repeat the rapid stopping sequence another 10 times.  During this entire process, you should notice the braking performance improves as the Performance Friction pads are broken in.



Well, there it is.  Disc brakes peaking out between the spokes of my rear rim.  I love the performance change I've experienced so far.  This is one mod that I couldn't have done without my SoCal buddy (and Robert's back bedroom to crash in for a few days).  A big thanks to both of them.

Note:  If you find your wheel studs are a bit short, check this out for a possible solution.

Note:  I pulled the following comment from an on-line forum where a friend of mine had just posted about the successful completion of his rear disc conversion.  He said:

"I used a set (disc brakes) from a '98 Grand with a D44A, not a D35. Everything went according to plan and the results seem to be well worth the effort. Hopefully I can get the TJ on a trail next weekend and really see how they perform.  All procedures were identical to using a set of discs off a D35c."


Parts List and Prices


Note:  The following list of parts was passed on to me from Rick E. from Spokane, Washington.  Rick did the disc brake conversion on his '98 TJ. 

Item Part Number Vendor  Price  # Needed  Total  Vehicle Year Comments
Axle bearings  Set 10 Timken NAPA  $     25.91 2  $     51.82 TJ Wrangler 1998
Axle seal Dana 44 18731 NAPA  $       9.79 2  $     19.58 TJ Wrangler 1998
Bearing retainers NA Mr. Blaine  $     45.00 1  $     45.00 TJ Wrangler 1998 Rubicon part number 
Brake tube, hose, and mount -- Left side 52128431AC Jeep Dealer  $     16.50 1  $     16.50 TJ Rubicon 2003  
Brake tube, hose, and mount -- Right side 52128430AC  Jeep Dealer  $     18.92 1  $     18.92 TJ Rubicon 2003  
Disk Brake Caliper ? Wrecking yard $20 2  $     40.00 Ford Explorer 95-'01 Came rebuilt with new pads.
Disk Brake Rotor 4886565 NAPA  $     36.98 2  $     73.96 Ford Explorer 95-'01 Should have used one from a Grand-thinner flange at axle than Explorer.  Short wheel studs.
Emergency Brake Cables ? Wrecking yard $20 2  $     40.00 Grand Cherokee 95-'98 Can use Rubicon as well.
Grade 8 bolts -- 8 total NA Hardware store  $       8.00 1  $       8.00
Loaded Backing Plate--e-brake  Left side 52128414AB Jeep Dealer  $     64.46 1  $     64.46 TJ Rubicon 2003  
Loaded Backing Plate--e-brake  Right side 52128415AB Jeep Dealer  $     64.46 1  $     64.46 TJ Rubicon 2003  
Mounting bolt kit, Caliper to Mounting plate 83177 NAPA  $       8.99 2  $     17.98 Ford Explorer 95-'01  
Proportioning Valve ? Wrecking yard  $     16.00 1  $     16.00 Grand Cherokee 95-'98 With 4 wheel disk brakes. Used one from a '95 which has same electrical connection.
T-fitting for proportioning valve 7900 NAPA  $       5.26 1  $       5.26 NA    
   $  430.12
Other useful parts
Rear disk brake hardward kit   NAPA   1   Grand Cherokee 95-'98 Springs, pins, adjusters, etc.  If rebuilding Grand Cherokee rear disk brakes.
Rear brake pads NAPA 1 Grand Cherokee 95-'98
Bearing retainers Dana 44 Jeep Dealer 2 TJ Rubicon 2003


More Disc Brake Conversion



4x4 Off-Road    Homestead    Firearms    RC Flying