Sparkytfl

This is for an 88, remember the setup changed for that year.

The parking brake failed inspection almost a month ago. Havent been able to drive it since. I'm told it needs to hold the car at a lightly accelerated rpm. It holds it to about 900, I'm assuming it should hold to higher than that.

The tension in the cable is fine. When I release the handle, the levers on the calipers are lightly at rest. No gaps which would cause dragging, and no looseness.

Leaves me with the adjustment screws on the calipers. First they were pretty far off spec, and each side pretty different from the other. Tried everything to turn them but failed, 3mm allen wrenches bent instead of turning it, and a socket bit I ordered snapped. Had to replace the calipers just to get ones that werent frozen up, which took several tries because one brand obviously never loosened and replaced the screws. But finally got new (reman) ones. Brake pads are new too, hoses new and bled.

Now I have the adjustment screws set at as close to the spec of .6 to .7mm as I could get it. (found a piece of metal about .65 and adjusted until i could slide it into the space.) It was set with somebody holding the pedal down and me pressing kind of hard on the levers.

The handle does feel like it should get a little tighter before it maxes out, and i remember it being a little bit tighter with the old calipers. But I dont know how far and which way to turn the adjustment screws to tighten it up. I imagine that if I get it a little above or below spec, it should tighten it up, without causing any problems like dragging, but dont know whether that thats correct and if I'd need more gap or less.

Any info, experience, or help with this would be much appreciated.

Sidney004

I solved this problem when I replaced the left rear caliper; it cured it.

pcolt94

Your (and mine) rear brake assembly is different that the 88. 94 uses the rear calipers for the parking brake and the 88 uses a separate drum with expendably brake shoes.

Sparky
You may need to do a brake job on the drum and shoes.

Few years ago we had a thread on how bad the parking brakes were and that they won't stop the car in an emergency. It was agreed that it was a parking brake, not an emergency brake.

DarkBlue88

My 95 Z28 has a similar setup. It wasn't working, and I found one of the pad pushers was jammed in the piston. Freeing it up helped, as did the new pads. My Vette's doesn't hold that well, but I think it would pass inspection. Can you take it somewhere else for an inspection? Sounds to me like they're nitpicking on your car.

Sparkytfl

The 88 doesnt use the drums, I'm pretty sure thats 87 and earlier. The cables all changed then too.

Just replaced the calipers, and played with them before putting them on, theres nothing jammed on them. It just seems like something's out of adjustment.

The guy might just be nitpicking, I did ask what rpm it should hold the car at but didnt get an answer. Took it to an oil change chain (car's older than everyone there, though I'm not much older). Afraid if I go somewhere else they might notice my incomplete AIR system (not on purpose, it was gone and functional diverters are hard to find cheap.) that these guys didnt.

pcolt94

I took a shot, was not sure what the change over year was but thought it was later with the drum setup.

In that case I would then use any information furnished by others. My parking brake sucks also. I do agree you the guy is nitpicking and there is no documentation at what RPM it should hold to. Sounds like a made up test and all cars no not perform the same.

Sparkytfl

Wasted three hours today screwing around with it with no luck. About the best I could get it to hold to was in the 900s.

It just seems like it should hold better than that. My 85 trans am when it had an even stronger motor and lower stall speed would hold to at least 1200, of course that had drum rears.

How high will it hold for those of you with working late-style setups?

Sparkytfl

I still cant get this. I realized that my front cable was a bit bent, forming a bit of a zigzag that would stretch as I pulled the handle. Bought a cable in good shape, installed with just enough slack to not drag, the adjustment screws on the calipers are set at spec.

The handle now pulls up much tighter (so tight that the plastic inside of it broke, fixed it now), but still this thing creeps forward at startup high idle (900s) even with the handle pulled so tight I can barely pull it any more. Maybe it's because I havent broken in my new rear pads? Havent done it because I dont have an inspection sticker.

Anybody who missed the thread the first time around have any ideas?

pcolt94

Just for your own information as another thread on the same topic. Just check it, it may give you some additional insite.

http://forums.corvetteforum.com/c4-t...rake-woes.html

Sparkytfl

Thanks, didnt realize somebody had created another thread in the week since I last bumped this one. I'll keep following that, but no help so far other than a vague reference to it seeming to work better when everything's warm.

Also I see that yours also wont even hold to 1000. I was hoping that a well-adjusted brake would work better than that, I may have trouble convincing any inspectors that it's normal.