BackInTheGame

I was intrigued by a Parts for Sale thread this afternoon. Is there any significant difference or advantage one way or another between installing a '67-'68 front disc setup VS '69-'72 setup? I see there are differences in the number of caliper pistons. Any reason to go four VS one? Or vice-versa?

allyolds68

I converted mine. The 67-68 dual piston caliper was a design that wasn't as good as the 69-72 single piston. A 69-72 caliper and disc is a direct bolt up to a 68 spindle. I reused all my other 68 parts (distribution block and hold off valve). I have had zero issues and the brakes work great.


BTW the 69-72 calipers and discs can be sourced from just about any auto parts store. As far as I know about the only people who still buy 67-68 dual piston calipers are Corvette owners... (and 68 H/O owners....lol)

BackInTheGame

Thanks for sharing your experience, Mike.

Rich

joe_padavano

To clarify, the 67-68 calipers are FOUR-piston fixed calipers - two pistons on each side of the rotor. The 69-up calipers are single piston sliding calipers. The four-piston calipers use seals on the pistons that slide in the bores. Because of this, any minor rust in the caliper bores chews up the seals, causing leaks. Stainless sleeves are the only fix. The later calipers use seals fixed in the bores and chrome plated pistons slide inside them. They are thus much less prone to leakage and much easier to repair if they do (new pistons are available).

Also, the fixed calipers are very sensitive to rotors runout, as any side-to-side motion pushes the pistons back in the caliper bores and causes very long pedal travel as a result. The sliding calipers simply move side-to-side and follow any rotor runout.

Finally, the single piston calipers (rebuilt) cost about 1/10 the cost of the four piston calipers.

BackInTheGame

Thanks for the additional info, Joe. Now I know which way to go when I tackle this job in the future.

Does it hold true that the '69-and-up Disc caliper assemblies will bolt directly to the '68 drum spindles?

IIRC from another thread, you stated that the original power drum-brake valve/switch module will need to be replaced with the corresponding Proporting Valve/switch module. Yes?

joe_padavano

No. Disk brake spindles are different from drum spindles. This website illustrates the differences. (Yes, it's a first-gen Camaro website, but the front spindles on 67-69 Camaros are the same as those on 64-72 A-body cars).

Disk brakes require a proportioning valve. You have two options, and functionally they are equivalent. You can either retain your current drum brake distribution block and use a separate in-line metering valve, as the factory did for the 1967-70 model years, or you can replace your distribution block with a combo valve that includes the metering/prop valve in the same housing, as done by the factory for the 1971-up model years. Either way works fine. The separate metering valve is "optically correct" for a 1968 car, but functionally it doesn't matter.

BackInTheGame

Thanks, Joe.

Rich

rob1960

I converted my '68 over to disc brakes last winter. I went with the "correct" dual bail style master & hold off valve under the hood but I went with the '69 up single piston calipers,like others have posted,they're much easier to get parts for!!. Inline Tubes' repop master is a very nice brand new casting with the factory bleeders & casting # on it.I saw it for $69 on their Motor City Super Car's( their Ebay store)site. Don't forget to order the upper brake line kit that has the 3 new lines for the disc brake master & valve,there's 2 kits one for power brakes,one for manual brakes. You'll also need the '69 up brake line mounting tabs that bolt on the frame(You'll have to drill the bolt hole for them as they're different than the originals). They are double the thickness of the '68 pieces so the '69 up hoses won't be tight when you try to put the clips on the hoses.

BackInTheGame

Thanks, Rob. That's a sano-looking build you've got!!

rob1960

Thanks Rich! I love all year 442s but '68s are my absolute favorite!!! I sold a real nice saffron/blk top holiday coupe that I restored back in '88 & I regretted it ever since!!! I looked for another one over the years & finally in 2012 the one I have now showed up on epay. While it's no perfect show car, it's super clean,never been in salt & fairly rare. It's a factory 350 hp/4 spd car with a/c. The paint job is around 20 yrs old but still very presentable. A lady ordered it new & she knew what she was doing!!! Along with the 4spd & a/c she ordered buckets,console,light group,gauges & posi for the 3.23 rear. I tracked down her # and tried to get a hold of her a couple of times but she never returned my calls Good luck with your build!!! looks like you have a real nice '68

lemoldsnut

Does anyone have a source for the metering block/valve new?

Never mind I did a little research and it is available in many places.

BackInTheGame

Thanks Rob. I've had mine for a few years now. Mine has buckets, 4spd, and A/C, also, but came with an open diff 3.23:1. I've got it stripped down pretty much at this time. I've been collecting parts for a few years and really got down to rehab'ing things this summer. I'll be installing a new-to-me OEM Rally Pack, headers/exhaust, and 3.42:1 Anti-Spin rear-end as it comes back together. Oh and another thing, even though it's not "correct," I'm going to add the W35 wing. I'm doing all of the rolling gear now, and hope to have it back on the garage floor on it's own feet by New Years. It was originally Blue/Blue, but the exterior was painted and the interior dyed black with aftermarket black carpet added. It will eventually be some shade of blue again, but the color/code has not yet been decided. I'll probably leave the interior black, though.

It's a blast working on my baby!

rob1960

I think I'm finally going to do the rear wing on mine over the winter also. I didn't want to drill holes in my nice original decklid but what the hell. I haven't had any luck finding a decent spare decklid for it & when one does show up for sale they want a fortune for it,plus a good chunk of change for shipping.The wing just flat out looks bad-***!!! The repop lid for converts has been out for years,I was hoping maybe one for the coupes would be coming but it doesn't look like it. As you can see I added the red fender wells & OAI setup,definitely not "correct on an a/c car but I just love the look of those red wells next to the turquoise paint!!