Got My Rear Discs On

[gator2511]

Will do. I should have them this Friday.

[BlueJeep]

I don't want to say anyone's experiences or opinions are right or wrong, so I'll just provide my actual experience.

I have had rear discs on my Jeep for 12 years now. I used weld on caliper brackets and I'm running K10/K20 front calipers on the rear (14 bolt if anyone cares). When I first did the swap I talked to the folks at SSBC, and they said to run it and if I have any issues then look to make changes. I was running 35" tires at the time, and had no issues and was able to lock up 35" tires with them. I've since changed to 38", and now 42" tires and I had very good braking performance with my stock 1988 Jeep YJ master cylinder, booster, and prop. valve. Because people were telling me I should, I swapped out my master cylinder for one from an E350 Ford van (disc/drum) for the larger bore and noticed NO improvement over my stock master.

Currently the Jeep runs 42" tires with the E350 master, stock booster, and stock prop valve and my braking performance is as good as it ever was. I have no complaints about my setup and I have no intentions of changing anything in the system. If I ever would change anything, it would be to plumb the front brakes directly to the master, and run the rears through an adjustable prop, but the balance is good how it sits now. The Jeep has been all over the Midwest and on the cliffs and mountains in Colorado and Utah and never have I been afraid that my brakes were unsafe.

BTW: I believe the gripe most people have with the Caddy calipers besides the cost is that the parking brake is finicky, and if you don't use it regularly it freezes up.

[gator2511]

Well I guess I'm in the same boat as you. The brakes work well now but I'd rather err on the side of caution. I really don't know what to expect but it should be interesting.

[Billhilly]

I'm watching this with interest too.
Got my discs (with caddy calipers) on back (a long way from driving anywhere yet) and have got a new disc/drum MC to put in. Really don't want to turn around and start replacing things straight away when I do get going.
Wondering if what bluejeep said might be a simple/adjustable way to go. "If I ever would change anything, it would be to plumb the front brakes directly to the master, and run the rears through an adjustable prop"
I already have a Wilwood adjustable prop valve here that I was going to run down stream of the stock one.
So many variables X so many opinions = !!!
Any feedback appreciated gator.

Bill.

[chris71]

[QUOTE=Billhilly;3351646]I already have a Wilwood adjustable prop valve here that I was going to run down stream of the stock one.QUOTE]

running the adjustable prop down stream with the original prop valve in place is a good idea because the original prop valve has the brake pressure switch built in and is wired to the idiot light in the dash. if you just run a wilwood adjustable, you wont have this, and if someday your MC starts to crap out and there is a drop in fluid pressure, you wont know until the MC gets bad enough that you can feel "something is wrong". Alot of guys will tap the adjustable prop valave into the rear line so they can fine tune the rear to there liking.

another point i'd like to bring up is application, different trucks are used for different things, if i had a truck that was mainly used for offraoding i suppose i wouldn't be as concerned with proper brake theory/design and idiot lights in the prop valve, etc, as long as i had good brake feel. however i drive my truck 60 miles everyday which includes downtown traffic, obviously here, i am more concerned about brake design/theory than just "feel" alone. if i have a brake failure in the offroad rig, i run into a tree, a brake failure in my truck, i hit a pedestrian or other car.

Here is a multi-page artictle discussing alot of brake design and theory, i encourage everyone who changes brake componants or just wants to learn something to read. they have a page on every componant: rotors, MC's, prop valves, calipers. etc. alot of it is catered toward race applications but still a wealth of knowledge here:

http://www.hotrodheaven.com/tech/bra...kes1_index.htm

[gator2511]

Billhilly, that sounds like a good common sense way to go. The thing to watch out for as I'm told is rear disc drag due to residual line pressure and master cylinder volume. (Thats in our applications) I had a chance yesterday to hit the brakes hard on a wet street and the truck came to a nice straight stop. As soon as I get the new parts on I'll post the results. chris71, thanks for the info, will read it today. Lots of activity around the house today.

[BlueJeep]

So I guess I should add that after I first did the disc brake swap on my Jeep, it was driven 400 miles per week for about 2 years. It no longer sees this kind of street time simply because the tires are too expensive and would wear out too quickly (42/15/17 Super Swamper TSL). I had zero problems or issues, and it was safer than a lot of other vehicles on the road. My application was primarily daily driving/commuting at that time and going off road approximately 2 times per month.

Again, I'm not saying anyone's opinion is right or wrong - I'm just providing personal experience.