Help! Calling all those who did a 14 bolt disc swap

[Mastiff]

Why the ever-present push to go to disc brakes? Is there some pressing need to ditch the OEM drum brakes?
(particularly if you have a newer 14bff with removable drums)

You could shed probably at least 100 pounds from the rear axle. If you do mud, discs don't pack up the way drums will. If you get it set up right, maybe there's less manual adjusting going on like with the stars. Routine maintenance is easier. Having said all that, I'm one of the ones with drums still.

 

[-stew-]

My rear brakes need everything replaced. Disc conversion is cheaper than replacing all the factory drum stuff.

 

[dremu]

Why the ever-present push to go to disc brakes? Is there some pressing need to ditch the OEM drum brakes?
(particularly if you have a newer 14bff with removable drums)

As CK5'ers we have the constant urge to "fix" things that aren't broken. Which then end up requiring actual fixes of their own.

I've done disc in about every way conceivable. On one truck I went back to drum. On the other, eh, I kinda wish I did.

Not to say that discs don't have advantages ... but they are not the be-all end-all and can require a fair amount of re-engineering of the hydraulic system, which can be beyond the ken of us mere mortals.

-- A

 

[campfire]

Not to say that discs don't have advantages ... but they are not the be-all end-all and can require a fair amount of re-engineering of the hydraulic system, which can be beyond the ken of us mere mortals.

I'm not so worried about the re-engineering effort (I like that stuff), but I don't understand why you'd want to put in the time required to rebuild if the drums are working. For Stew, I understand switching out when the drums are fully shot. For my situation (and I assume many others), I have so many things higher up on my list of priorities....

As CK5'ers we have the constant urge to "fix" things that aren't broken. Which then end up requiring actual fixes of their own.

This quote sums up the whole site. Might have to make a sig line out of that.

 

[The Pumpkinator]

Well based on some testing with a digital thermometer the rear discs average 120-160 degrees ferenhiet, drove 400ish miles to Moab UT and the discs weren't any hotter, in fact the front discs were 10 degrees warmer than the rears.....

However I may have a bad pinion bearing, I'm getting a loud howling/ humming coming from the rear end at certain speeds, the sound almost matches that of driving on rumble strips of the side of the freeway.

 

[wheels87k5]

As CK5'ers we have the constant urge to "fix" things that aren't broken. Which then end up requiring actual fixes of their own.

-- A

That explains why I have spares of all the sensors.

 

[wheels87k5]

I'm not so worried about the re-engineering effort (I like that stuff), but I don't understand why you'd want to put in the time required to rebuild if the drums are working. For Stew, I understand switching out when the drums are fully shot. For my situation (and I assume many others), I have so many things higher up on my list of priorities....

I chose to swap to disc when I found a set of caddy calipers and later the springs and brackets, for a decent price. I like to work/build on things so priority had nothing to do with it. I was curious on the pros and cons so I decided to do the swap. And after some researching and re-engineering I now have an awesome set of brakes.

I replaced the proportioning valve by running the line from the MC to the front calipers (using a tee), and using an adjustable valve for the rear.....drove around until I got the right setting......Same as sweetk30 did.

And with the caddy calipers I was able to adjust and set the parking brake. I don't know how well the drums worked because I did the swap before I used them. But the discs hold great.....no complaints here.

As said before, there is nothing wrong with keeping the drum set-up. And if you have the time and money, and nothing better to do, there's nothing wrong with disc brake either. They both work if you get them adjusted correctly, or re-engineered.

 

[diesel4me]

I've been tempted to do a disc swap every time I step on the brakes for the first stop every morning or after the truck sat awhile..
GM drum rear brakes love to be extra "grabby" and lock easily after that rust builds up overnight on a drum surface..this can cause big problems if it is slippery out in winter!..other than that they work fine for me..

The only drawbacks to converting to rear discs I can think of is the E-brake dilema,and Caddy calipers getting harder to find and rigging up the E-brake cables to them..but I have managed to live with drums all my life in the rear so far,and parts for them are fairly cheap,except maybe the drums themselves--they aren't fun to replace the shoes on,(or E-brake cables either!)...but I have only had to change them once as long as I have had my trucks & cars ...

 

[campfire]

I chose to swap to disc when I found a set of caddy calipers and later the springs and brackets, for a decent price. I like to work/build on things so priority had nothing to do with it. I was curious on the pros and cons so I decided to do the swap. And after some researching and re-engineering I now have an awesome set of brakes.

I replaced the proportioning valve by running the line from the MC to the front calipers (using a tee), and using an adjustable valve for the rear.....drove around until I got the right setting......Same as sweetk30 did.

And with the caddy calipers I was able to adjust and set the parking brake. I don't know how well the drums worked because I did the swap before I used them. But the discs hold great.....no complaints here.

As said before, there is nothing wrong with keeping the drum set-up. And if you have the time and money, and nothing better to do, there's nothing wrong with disc brake either. They both work if you get them adjusted correctly, or re-engineered.

Yeah...I probably will do the swap eventually for just those reasons. I like to tinker. But I haven't found a technical reason why everyone else seems to want discs, unless they're concerned with mud accumulation. So if there's not any real difference, I'm not gonna mess with mine until I get bored (which may be a while )

 

[CGT80]

The drums on the 14bff of my 79 c20 would never stay adjusted. I had changed all the parts and had multiple people check my work.

I went with a kit with caddy calipers. The stopped good at first, but the calipers never stayed adjusted, and the adjustment for the parking brake effected the hydraulic brakes. I had changed the master, booster, and front rotors, and pads as well. I averaged 60k miles per set of pads with powerslot rotors and hawk hps pads. I had a different proportioning valve that replaced the factory one.

I finally went for the front calipers with no e brake. Now they work awesome. I would rather have no e brake and great hydraulic brakes than what I had. I never have to adjust them, and it stops on a dime.

 

[dremu]

Well based on some testing with a digital thermometer the rear discs average 120-160 degrees ferenhiet, drove 400ish miles to Moab UT and the discs weren't any hotter, in fact the front discs were 10 degrees warmer than the rears.....

Well, remember the front brakes, regardless of flavour, carry most of the energy, braking duty or power, whatever you wanna call it. I think this is 'cuz generally the vehicle is heading forward when you brake This is why on a factory disc/disc vehicle the front rotors and calipers are larger than in the rear.

-- A

 

[Mastiff]

Well, remember the front brakes, regardless of flavour, carry most of the energy, braking duty or power, whatever you wanna call it. I think this is 'cuz generally the vehicle is heading forward when you brake This is why on a factory disc/disc vehicle the front rotors and calipers are larger than in the rear.

I think it's because the vehicle noses down and puts more weight on the front, so more brake can be applied there before the tires will skid.

 

[dyeager535]

This is why on a factory disc/disc vehicle the front rotors and calipers are larger than in the rear.

GM actually used larger or same size disks front/rear on some of the later Astro and/or full size vans. Don't quite see the reasoning unless it helped with braking when towing. Only reason I can think they would have done that since fronts do way more work in normal driving than the rear. I looked closely at that setup as some applications used the 14SF or 10 bolts.

After all I've seen of the disk conversions, including experience with the caddy setup on these trucks, I'm of the opinion that option isn't ideal. The disk/drum disk/disk conversion problem (in regards to brake bias/proportioning) is clearly demonstrated with the 90's Impala SS that GM apparently screwed up (or went cheap on). The fact that GM abandoned the Caddy design calipers for drum in hat indicates the system was flawed, not to mention the problems people still have with them.

I would much prefer to see the later design rear disk setup made to work on the older trucks, but the caliper position seems to indicate that you would have to run 16" wheels, without exception, and I know that isn't an interest for some of us.

 

[modernbeat]

Seems like the best solution would involve using the new AAM axle brakes IF you were going to 16" wheels.

Looks like Right Gear make a bolt on bracket that adapts the brakes to the 14b.

http://www.pirate4x4.com/forum/misc-stuff-sale/985215-full-disk-brakes-newer-14-bolt-e-brake.html

Not listed on their site. I've heard they run about $250.
http://www.rightgear.com/welcome.htm

Very similar would be to adapt the brakes of a Ford Dana 60 from a '99 and later E350 (one ton van). The parts look a whole lot like the AAM brakes.