Drum to Disc Brake Conversion?

I saw this posted on another forum and thought I'd get opinions from ya'll. Has anyone converted their rear drums to disc brakes? Pros? Cons?

 

http://www.tundraracing.com/rbck.htm

Not yet, but it is on the list. The kit is cheap enough and I am mechanically inclined...it does not seem too daunting. I question whether or not I want to mess with brakes that are spot on. Maybe someone that has done it can chime in about if the brake performance increased significantly or not.

Side note: I have been following the 'rear disc' trend for a little while and am concerned that it really is just a trend. For example, when Chevrolet did a redesign of the 1500 they switched to disc brakes on the rear but recently went back to drums on the rear? Some say drums are cheaper but wouldn't it be cheaper to use the same parts at all 4 corners instead of having seperate parts just for the rear? I am a little biased though as my 2005 Froniter Nismo 4x4 had rear discs and I loved/miss that truck.

 

i've heard to stay away from this conversion. use the search button.

 

I like good brakes and I think the brakes on our trucks are pretty weak but that is a sign from god to drive our trucks slower than we drive, lower CG cars. I let it remind me to drive, well, like the 62 year-old that I am!

 

Having worked for GM (Desert Proving Grounds) I'd say if GM did it, it was to make it cheaper. Now when you see race bikes, cars and trucks using drums up front - now that would indicate drums are the best... they are not. Cross a river with drums, cross a river with discs - which condition would you rather have?

 

I raced mountain bikes professionally for several years and lived through the conversion from rim brakes to disc brakes. Mud and water are HELL on brake pads for either system and one ride with river crossings and mud almost always meant new pads. The rims brakes would almost always pack up but the discs would always work no matter how loud the squeeling and chattering got.

That being said, I recently built up two bikes, a vintage Klein Mantra Carbon Race with Hope 4 piston discs and a UK only 2008 Trek 8900 with M952 XTR rim brakes. I have CONSTANTLY been adjusting the disc brakes but the rim brakes are spot-on and I can literally bring the bike from a full haul to a complete stop with one finger.

I know, bikes and trucks, apples and oranges...

 

Folks who have tried the conversion (MJP2 is one I think) were not pleased with the performance. They are different systems and the truck was built to utilize the drums in the rear.

Both have up and downsides- Save your coin and upgrade your lines, fluid, and pads...Rotors if you want...but converting the rear end seems like thorwing money after something that isn't a problem...imho.

 

I hear you on the paper thin mtn bike dealios - I have 3 mtn bikes and love my Magua brakes and my rim brakes - but overall, I still like the perf of my discs. I can understand.

RE our trucks - I think I will mod something else or put it towards an 80's toyota truck.

Edit: I do like the look! But then again, I would have to wash my truck, polish out the trail stripes, pull then dents, etc - to allow someone to focus on the discs.

 

Front Range off-road, makes a full floater conversion that also converts to rear disks, that would be the way I would go, not only getting better performance with the disks, also gaining a lot of strength with the full floater axle!

 

Best of both worlds:

http://www.chainreactioncycles.com/Models.aspx?ModelID=30752

Magura hydraulic rim brakes were an industry standard.

 

Someone here in San Antonio has rear discs on their X-Runner and it LOOKS nice, I wonder how they perform though. I see him driving around the O'Conner/35N area every once in a while (Black X-Runner). Maybe he's on this forum and will give his input.

 

Hey thanks! I've been buggin a guy a ride with the do something with his brakes - they are SCARY!!! This would be a great way to go for him. Thanks!

 

It's not something you can bolt on and walk away.....

Drum to disc conversions also require different master cylinders & proportioning valves. And with the ABS / TRAC / etc - all those systems and where the computer control is involved.... You're better off not messing with it.

I converted my Jeep Wrangler from drums to discs. No ABS. No traction control. No computer input. I replaced the entire master cylinder to disc/disc master cylinder and the prop valve to disc/disc prop valve. It was better than before but it still wasn't ideal. THe jeep was my trail rig. I would never do that on a daily driver and feel SAFE.

 

I guess I'm old too. The brakes work just fine as they are so why spend big $$ just to spend big $$$ ?

The rear (drum brakes) on my my 1st gen were in really good shape when the truck went to it's new owner and it had 134,000 miles on it. They were the original brakes.

 

If it ain't broke, dont fix it!

 

X3

 

never had a problem with the rear drums on my '88 toyo truck...drove it well over 300,000 miles...i think i changed the pads once...maybe twice the whole time

 

The price is out to lunch on the tundraracing kit.

Rear disks have more potential then drums but that doesn't mean that they are always an easy swap. Disk brake calipers often require more fluid then the drums so the stock brake master isn't designed to push that much fluid to the rear lines. Most guys running rear disks add a residual valve to help. Smaller calipers that require less fluid can help as well. As was mentioned before, the hard part is not putting on the disks; it is designing a system that all works together so that the disks can perform to potential.

The front brakes still do ~75% of the braking so your money would probably be better spent up front first. Also if you if you improve the rear greatly it can throw off the bias and still end up with worse braking overall then stock, or end up having to tune out most of the performance increase to maintain the bias.