Brennan’s Disc Brake Conversion - Question

[53Flattie]

Mid-project update on this - I have all the parts installed and bled. Test drive will be tomorrow and I’ll report back.

Everything went together pretty smoothly. A couple snags I experienced, that might help others…. The Honda Accord brake hoses have a flat spot where they go into the brake hose retaining tab on the frame. The factory tab has a round hole. I used a dremel tool to reshape the opening so the hose would go in and accept the retaining clip. Not a big deal, but something to keep in mind.

The Sidekick rotors have to be drilled out to pass over the wheel studs. The CJ5 swedged studs are pretty large, so I would recommend a step-bit and take your time.

I had to use a 1.25” wheel spacer to clear my 7”
wide wheels. Might have been able to get away with 1”, but I had 1.25” laying around so I used them.

I tried to use longer bolts through the spindle/disc bracket. The factory bolt is just under 1”, maybe 7/8” or 15/16”. I tried a 1.25” and it threaded in great, but it interfered with the kingpin when turning. I just went back to the original bolts bc I think the disc bracket is only about 3/16” thicker than the original drum backing plate and I felt like there was plenty of thread engagement with the original bolts.

 

[53Flattie]

Final update on this project, after driving the Jeep on a couple short trips yesterday and today.

I decided not to mess with the residual pressure valve until I tested it to see if the brakes would drag. I’m happy with that choice as I haven’t experienced any dragging at all. Even jacking up the front axle and spinning the tire by hand after stepping on the brakes, I get no drag.

The discs require less pedal pressure than the drums. Lightly pressing the brake pedal is enough to almost come to a stop.

I had 11” drums all around. How much of an improvement are the discs? I’d say maybe 20% better. To be honest, I expected that it would be a bigger improvement. But I didn’t necessarily have any “problems” with my drums. I really just wanted to try Brennan’s kit and needed a project.

Would I do it again? Probably. It was fairly easy, and not that expensive (maybe $400 total). Discs are lighter, easier to service, and perform better when wet.

If you have 9” or 10”, I’d say you’ll definitely get more bang for you buck by going to discs. If you already have 11”, I would put off the discs until you’ve ran out of other projects (like me).

Just my .02. YMMV.

 

[47v6]

When I had the 9x2 eccentric adjusted brakes on my 47, I put on 11” bendix style drums. That was the most importantly modification I did on it.

Disk brakes are an improvement over those. As you break in the pads it will stop better. Have fun!

 

[Smcnish]

Final update on this project, after driving the Jeep on a couple short trips yesterday and today.

I decided not to mess with the residual pressure valve until I tested it to see if the brakes would drag. I’m happy with that choice as I haven’t experienced any dragging at all. Even jacking up the front axle and spinning the tire by hand after stepping on the brakes, I get no drag.

The discs require less pedal pressure than the drums. Lightly pressing the brake pedal is enough to almost come to a stop.

53Flattie, thank you for the information! This will be my very first modification, and I'm paranoid my first test drive will end in a fireball at the end of my driveway.
I’m gathering all the parts for this project and completely overlooked that the Honda lines need an adapter. Am I understanding correctly that you did no modifications to your master cylinder, you did not remove the RVP from the front and add the 2 pound?
Thanks

 

[53Flattie]

53Flattie, thank you for the information! This will be my very first modification, and I'm paranoid my first test drive will end in a fireball at the end of my driveway.
I’m gathering all the parts for this project and completely overlooked that the Honda lines need an adapter. Am I understanding correctly that you did no modifications to your master cylinder, you did not remove the RVP from the front and add the 2 pound?
Thanks

Correct - I didn’t do any modifications to the master cylinder, nor did I add a residual pressure valve. But let me be clear that I have a newer dual-pot MC - in case that makes a difference.

 

[Smcnish]

Excellent, I also have the dual-pot MC. I think I will give it a try and just monitor if the front pads drag. Thanks!