Soon as I get released from Dr., I plan to start converting from rear drums to disk on the 12 car. Looking at these caddy calipers as the easy button because of the built in parking brake feature. Power Stop even makes track day pad to fit them.
Wondering though, if there is anything about these calipers that will not hold up to the heat from 20 min sessions on a road course?
Decided to get a cheap set off Amazon to try...
I believe I have China's finest "bark caliper"!
They're the same as the 1980 / 1981 Trans Am rear disc calipers, just the levers are swapped left-to-right.
They work fine as brake calipers but the parking brake feature is more decorative than functional.
The pistons screw back into the caliper, rather than push. A few have been broken by ham-fisted mechanics.
Good luck!
If you use them, use the parking brake frequently or they will seize up. I had them on a 1978 Buick Riviera and didn't used the park brake because, auto transmission. When It needed rear brakes I had to replace the calipers because the piston would not screw back in.
Unless there is some dire need to use these old calipers, why not a set of dedicated parking brake calipers from Wilwood? The "screw it out and hope it works" means of setting the clamping force for parking brakes never gave me the warm fuzzies or was particularly robust.
93gsxturbo said:Unless there is some dire need to use these old calipers, why not a set of dedicated parking brake calipers from Wilwood? The "screw it out and hope it works" means of setting the clamping force for parking brakes never gave me the warm fuzzies or was particularly robust.
Or wilwood does make a couple of calipers with it built in.
Informative site about Caddy E brake calipers:
Not All Eldorado E-Brake Calipers Are The Same | Lugnut4x4
I have a set on the rear of my '71 Bronco (Dana 60 full-float axles, custom caliper brackets), using 12" 3/4 ton 8 lug GM rotors. No road course testing as of yet.
Well, after buying a set of these calipers and looking them over, I think I'm going to go a different route... They just seem way to fiddly for me.
I think I'm going to use my old front calipers (if I didn't junk em) on the rears and buy the wilwood parking brake caliper from summit just for one side.
Anyone see any issue from only having parking brake on one wheel?
gsettle said:Anyone see any issue from only having parking brake on one wheel?
you mean aside from only having 50% of the intended grade holding ability?
AngryCorvair (Forum Supporter) said:gsettle said:Anyone see any issue from only having parking brake on one wheel?
you mean aside from only having 50% of the intended grade holding ability?
No, that's what I mean lol. Will the Willwood hold the one wheel well enough?
Never seen one in person but they kinda look like they are motorcycle sized.
https://www.summitracing.com/parts/WIL-120-15484-BK
Parking brake on both rear wheels, no question. With it on one wheel, unless the diff is a locked/spool, the car could still move as the other wheel can turn with the driveshaft.
gsettle said:AngryCorvair (Forum Supporter) said:gsettle said:Anyone see any issue from only having parking brake on one wheel?
you mean aside from only having 50% of the intended grade holding ability?
No, that's what I mean lol. Will the Willwood hold the one wheel well enough?
Never seen one in person but they kinda look like they are motorcycle sized.
https://www.summitracing.com/parts/WIL-120-15484-BK
neither wilwood nor summit say anything about the clamp force this caliper will produce. they do state that it has sintered semi-metallic pads which provide high static friction, but how high is high?
i don't have enough info to answer your question.
81cpcamaro said:Parking brake on both rear wheels, no question. With it on one wheel, unless the diff is a locked/spool, the car could still move as the other wheel can turn with the driveshaft.
grade holding is not a function of diff type. the things that do matter are:
there are three possible outcomes:
I can understand not wanting to go with these rear calipers. I have a 1979 Trans Am WS6, so it has the slightly different version of these. They were a pain to get sorted so they worked as they should. On these, the calipers don't provide 100% braking capability unless the e-brake cable system is sorted and adjusted properly. Mine were frozen solid for decades up until very recently, so they never really worked as they should have.
And yes, you'll want two of those parking brake calipers. No question there. Better safe than sorry!
In reply to gsettle :
back to your original post, what exactly is the 12 car and what rear end does it have? there have been a whole E36 M3-ton of cars made with integral park brake rear calipers since those old Caddy parts came down the line.
AngryCorvair (Forum Supporter) said:In reply to gsettle :
back to your original post, what exactly is the 12 car and what rear end does it have? there have been a whole E36 M3-ton of cars made with integral park brake rear calipers since those old Caddy parts came down the line.
The 12 car is actually my 5.3LS/AR5 swapped 98 GMC Sonoma truck. It still has the 7.5" factory 4.11 rear with a LockRite locker. I use it for SCCA Time Trials (some national, mosty Indy series) and a little bit of autocrossing.
In reply to gsettle :
Any reason you didn't go with a S10 Blazer rear disc setup with the integral parking brake drums? Just curious. I have a spare 8.5" 10-bolt for my Trans Am that I was going to convert over to that setup when I spruce it up.
Tony Sestito said:In reply to gsettle :
Any reason you didn't go with a S10 Blazer rear disc setup with the integral parking brake drums? Just curious. I have a spare 8.5" 10-bolt for my Trans Am that I was going to convert over to that setup when I spruce it up.
that sounds like the easy button right there
Tony Sestito said:In reply to gsettle :
Any reason you didn't go with a S10 Blazer rear disc setup with the integral parking brake drums? Just curious. I have a spare 8.5" 10-bolt for my Trans Am that I was going to convert over to that setup when I spruce it up.
I'm gonna try to keep the 7.5" for a couple reasons... lighter weight and I've already put $$$ into it. Mainly for the weight though. I've been working to get as much weight off the truck as possible, including a goal of getting 40# out of the drivers seat before the first event this year.
If I do have to upgrade, my plan is to use an 8.8 explorer (I almost said the F word) type rear.
gsettle said:Tony Sestito said:In reply to gsettle :
Any reason you didn't go with a S10 Blazer rear disc setup with the integral parking brake drums? Just curious. I have a spare 8.5" 10-bolt for my Trans Am that I was going to convert over to that setup when I spruce it up.
I'm gonna try to keep the 7.5" for a couple reasons... lighter weight and I've already put $$$ into it. Mainly for the weight though. I've been working to get as much weight off the truck as possible, including a goal of getting 40# out of the drivers seat before the first event this year.
If I do have to upgrade, my plan is to use an 8.8 explorer (I almost said the F word) type rear.
check with an S-truck expert, but from a manufacturing POV i'd expect the axle ends to be the same between 7.5 and 8.5, so the rear disc swap could be a bolt-on.
AC,
I'm almost sure you're right
Some of the drum 7.5 axles used a 3-bolt flange, so verify what flange your axle has. Below is an image of the 3-bolt flange.
In reply to gsettle :
I'm kind of surprised that the 7.5 has held up so well to the torque of the 5.3, especially with 4.11 gears. I would have thought that you would be close to the limit of breaking it.
JBinMD said:In reply to gsettle :
I'm kind of surprised that the 7.5 has held up so well to the torque of the 5.3, especially with 4.11 gears. I would have thought that you would be close to the limit of breaking it.
Power isn't usually what kills those axles, it's traction.
Can you pull info from the fbody crowd about disc swaps? Thirdgen people have been swapping to discs forever. Unbolt all the stock stuff, cut off the top of the axle flange and rear drill a couple holes.
https://www.thirdgen.org/ls1reardisc/
Have them on my truck. Seem to work fine. Currently need to fiddle with the parking brake but it may be a cable issue.
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