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73-87 Chevy _ GMC Trucks => Brakes, Frame, Steering & Suspension => Brakes and Braking Systems => Topic started by: Skunksmash on August 08, 2009, 12:28:08 pm

Title: Cheapest, easiest rear disc conversion?
Post by: Skunksmash on August 08, 2009, 12:28:08 pm
I know we got that article in the tech forum but is that generally thought of as the cheapest easiest rear disc brake conversion for our trucks? I just have a general distaste for drums. So I am looking for the cheapest possible conversion for my '87. Maybe someone has come across something better by now? It seems like there should be a way where you don't have to do any cutting/grinding.
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Engineer on August 09, 2009, 01:38:43 pm
I used some old parts that I had laying around to build a 4 wheel disc setup for my '77 K-30, and my son's '79 K-30. It uses the front caliper, rotor, and backing plate from any year 3/4ton 4x4. I should note that this is only for the GM 14-bolt FF rear axle

I had to have a spacer machined for it, but it works like it was a factory install.

Since the 3/4-ton parts were some that I had laying around, and the spacers were machined by a friend, all that I have invested in total in the 2 conversions are a case of beer for the spacers.

I may be able to post the plans, and how I did mine if your truck is a 14-bolt FF, and you are interested.

I am removing the rear discs from my truck when I rebuild it into a full time sled puller, so I wont be needing my rear discs anymore.
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Skunksmash on August 09, 2009, 07:05:28 pm
Anyone know what those factory GM brakes came off of, that had the heat disapating fins on them? Or perhaps a factory 2 piston caliper for the front?
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Captkaos on August 09, 2009, 10:05:51 pm
The kits that are bolt on aren't going to be "cheapest" except for the bang for the buck.

Did you see this? http://www.73-87.com/7387garage/chassis_suspension/reardisc.htm
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Skunksmash on August 09, 2009, 11:04:31 pm
Yeah, but that's one of the things i was concerned about when doing a conversion. That particular conversion has a lot of disadvantages to it. You can get single piston conversion kits from JCWhitney for around $484 (i think that was the price, i'll go check) and he says that he spent well over $800 doing the conversion that he did in that article. Another disadvantage of that conversion (at least in my opinion) is that you have to set the parking brake every time you park. That's what he says. Just really not my cup o' tea to have to do that. He used a system off a mid 80's caddy, I was kind of wondering if something a little newer might be called for, these days. Maybe the set off the rear of an Escalade? Or a newer truck? What is it that makes the newer stuff not fit?
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Captkaos on August 09, 2009, 11:16:00 pm
CPP/wilwood has a setup, but it isn't cheap either.   There are several companies to look at,
CPP, SSBC and Baer to name a few.  They use newer parts.
Title: Re: Cheapest, easiest rear disc conversion?
Post by: DnStClr on August 10, 2009, 09:41:40 am
Wow, Skunks, it sounds like engineer has the plan for you if you're looking for cheap.
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Engineer on August 10, 2009, 10:14:42 am
I should've also mentioned that my setup uses the front calipers from the 3/4ton. So no parking/emergency brake. My set up only works with an automatic transmission, or a line-lock on the rear brakes.

Line-locks aren't street legal in most places.
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Skunksmash on August 10, 2009, 10:09:16 pm
Im not really concerned with what's street legal. i just want to make sure everything is compatible. Although Im still wondering why someone couldn't just go get a front brake set off some newer caddy. Im sure there is a reason, i just don't know it. In other words, i don't know what part exactly make them incompatible. If I find any out about any good swaps ill post it up.
Title: Re: Cheapest, easiest rear disc conversion?
Post by: Captkaos on August 11, 2009, 12:05:32 pm
Most vehicles employ a hub/disc as the same piece.  Nothing new that I know of uses the 5 on 5 anymore EXCEPT a Jeep TJ from 2000 up.  So you possibly have hub/rotor issues, bolt pattern issues, caliper mounting issues, etc.  Plus, all front discs don't have a parking brake.

The CLOSEST thing to bolt on with a parking brake is a Impala SS from 94-96. They have the same bolt pattern.  BUT you still need to make caliper mounts.  This has been discussed many times.