Hello All,

I've got a 65 Dart conv with an 8 3/4 SBP rear end and a 65-72 SBP K-H front disc brake setup. The brakes were done a couple of years ago when the project started and she hasnt been driving a whole lot while the project has been completed. I took her out for a test drive today and noticed a couple of problems. First off, I forgot a proportioning valve and as a consequence the rear locks up too soon under heavy braking. Summit to the rescue.
The other problem is what I need some advice on. Especially from other SBP K-H owners. I noticed the pads dragging and took off the wheels of to inspect. It looks like the pistons are sticking and not returning all the way. To make matters worse my friend stripped the right side bleed screw while we were bleeding the system. So now I need to take off at least one if not both calipers for rebuild/ tapping.
I was thinking though... these things are damn near forty years old and not available aftermarket new. Is this sticking thing a problem from the old rusty piston bores? if I get my caliers rebuilt and the piston bores sleeved, what's this goona cost? Should/ can I upgrade to an aftermarket sbp system for a reasonable amount of money and maybe get around this whole issue? Maybe even get cheaper, more available rotors out of the deal?
Thanks for your thoughts!

-Ned

While you're at it, put in the 13/16" bore rear wheel cylinders, which will do the bulk of the job of getting the premature lockup out of this system. Use the prop valve for fine-tuning, not for gross choke-off of the rear brake system. See here for details.
They probably are. This is not an uncommon failure with the KH 4-piston calipers. The main cause is failure to get the seal boot groove in the caliper casting all the way clean during a rebuild. Even a small amount of rust, crud, old rubber, etc. holds the boot out of the groove and allows moisture to penetrate, rusting the piston in its bore and causing sticking. Chasing the groove with a sharp screwdriver is OK if the calipers are fairly clean to start with, but putting them in a blasting cabinet and shooting brake lathe grindings (or glass beads) at 'em is even better, paying special attention to those seal grooves. Other preventives at time of rebuild include brass or stainless sleeving of the caliper bores. If you want to be sure NEVER to have the problem again, you could spend $500 on Stainless Steel Brakes' Aluminum caliper set with stainless pistons.

With the K-H brake setup, it's really critical to keep the brake fluid clean and DRY. Flush through and refill every two years (or every year if you live in a wet area).
See above.
Check with e.g. White Post Restorations or any of the many other sleeving places advertising in Hemmings on that one. The actual rebuild is easy; the hardest parts are prying stuck pistons out of their bore (you're not supposed to use a pair of screwdrivers; I've done it anyhow) and finding someone to PROPERLY clean up the castings, see above.

Do you have a disc brake master cylinder?(small reservoir,big reservior)if you do good.

If you have a drum brake master it will cause the disc's to drag.The reason is because of something called residual pressure valves.This is suppose to keep air from entering the system.This keeps a few PSI of line pressure in the lines at all times.NO GOOD FOR DISCS!!!

Also when I did the kelsey hayes conversion I just bought rebuilt calipers,gave them the old crusty calipers as cores.Saved time and hassel.

Hope this helps

JZ

The rear 10" drums have the 13/16" bore rear wheel cylinders and my lock up issue isn't that bad but could definitely be improved with a little adjustment from a prop valve. I do have a disc master cylinder and put in the 15/16" bore one into reduce pedal pressure. The aluminum caliper set is intriguing, I live in the NW and don't really want to warp rotors dragging pads but damn $500 ain't cheap on the other hand Layson's wants $320 for a set of rebuilt cast iron calipers so that doesn't seem so bad. Anybody have the Aluminum caliper set with the stainless pistons? And how much for the rotors if you do??

WOW!! $320.00 for calipers.Between you and me Laysons is the last place I would be going for brake parts.I paid $140.00 for a set of rebuilts.Of course that was a bro deal,but they can be had for less than $100.00 a side loaded.



JZ

Just FYI, the residual pressure valve can easily be removed from a master cylinder that has it, or installed in a master cylinder that doesn't. The front section of the master cylinder (which feeds the rear drum brakes on the car) will generally have an RPV if it is a pre-1974 master cylinder. In '74, wheel cylinder seals were redesigned and the RPV was eliminated from even drum brake master cylinders.

Never buy mechanical parts from Layson's—dude thinks his shìt is gold-plated and he hasn't got many mechanical parts that cannot be had less expensively elsewhere. I only buy from Layson if he is genuinely the only source for an item. Rebuilt cast iron calipers are readily available; go look on RockAuto.com and you'll see 'em. The "lifetime" pads the Raybestos PG calipers come with are yucky; way too hard (too aggressive on rotors, pedal pressure too high) but pads are easy to change.

The aluminum calipers work with stock rotors.

So I went to RockAuto and found out that these rebuilt models are raybestos, cheap at $70 bucks a each semiloaded, and my local parts shop can get them tommorow. Thanks so much. When I called the parts shop yesterday they couldn't find them, oh what a difference a part number can make. I'll just deal with keeping the pston bores clean.

I did call up SSBC and the funny thing is you can get Aluminum/Stainless calipers but not slotted rotors for the stock K-H setup. They only offer the new rotors for the drum aftermarket kit. So I thought it kinda funny to run a nice light caliper with the stock rotor. Anybody know of a good place to get quality rotors? I don't need them now but someday I will when my junkyard set is done.

-Ned

Nothin' wrong with stock rotors if they're of good quality (I haven't looked lately—these rotors went N/A about 12 or 13 years ago and were extremely hard to get for awhile, now suddenly they're available again (thanks to the Mustang resto crowd...?). Slotted rotors aren't necessary. I do slot the brake pads, dividing the brake pad surface in three with two diagonal slots (aft inboard to fore outboard) cut with a hacksaw after putting masking tape on the pad surface. WEAR A DUST MASK and otherwise do asbestos you can to keep dust down (get it? Asbestos you can?).

If I wanted super-duper, I'd buy a new set of rotors, have them cryogenically treated, mount 'em on hubs, have 'em trued up and be happy for a long time.

One of these days I would like to find a couple of the one piece police rotors.

JZ

I've been following this thread as I'm getting ready to do the KH swap to a 65 Barracuda and then a 65 Valiant convert. Does anyone know if the LH wheel studs are readily available. You ask why not convert to RH. I would if I didn't have 2 complete NOS sets (10 LH/10RH) of the long wheel nuts used with the 65/66 sport hubcaps, which is what I'll be using on both vehicles. I'll be danged if I pay Layson's price of $300 for a set.

The LH-thread wheel hardware is easily available. I know Dorman still catalogues it (the orange drawers at the back of a well-stocked hardware store), and it's probably available from NAPA, too.

Dan, Thanks for the info. I'd heard LH studs were available for drums but were NLA for the disc. Any idea of a part #. If not will have to check at my local NAPA. I understand that the actual rotor is secured to the hub by the pressed in studs. Would you know if that's correct? BTW, would you be the owner of Daniel Stern Lighting?

65DM, I'll check my Dorman book at the office tomorrow and let you know what I find.

Yep, Daniel Stern Lighting is me.

Dan - Thanks for all your help! I'd like to talk with you about upgrading the lights on my 65s. I will check your site and give you a call.