beernut

This happened today as I was heading back from a car show here in town. Great day, great weather - and it almost ended in a big pile of crumbled Corvette pieces...

When I left the show, brakes felt OK - nothing unusual. Had a 5 minute drive to get back towards the house and didn't notice anything unusual while driving. However, at one point I gunned it and had to immediately brake quite hard in order to avoid a car that pulled out in front of me. Luckily I had about 50ft to stop but the damn brakes did nothing...pedal mashed all the way to the floor before any stopping power was felt!

Anyway, I got back to the house safely at crawl speed (had less than 1/2 mile to go.) What's strange is that while the engine is not running - I can pump the pedal hard. As soon as I crank it though, I can mash it to the floor and barely get any braking power.

Any idea what might be going on here? I'm thinking it's best to take it to a shop to have them fix it - but the more info I can have going in, the better.

Thanks!

wombvette

Bleed em.

beernut

OK, so you think that's all it takes? Does air account for proper operation and then all of a sudden no brakes? Sorry if that's a stupid question, but I've never had anything like this happen before

Peterbuilt

Bleed the brakes then go for a ride, if the problem comes back you have a run-out problem.

beernut

Alright, I'll give it a shot tomorrow - thanks guys!

bobs77vet

it seems like you have had a catastrophic failure....from a hose bursting or more likely the seals giving way in the caliper....start looking for leaks and puddles on the floor. i bet you have no pedal while the car is running because the power assist is coming in and pushing the fluid through the leaking spot. if you find no leaks you may even have had a master cylinder failure

beernut

You Sir, were right on the money. It was the front left caliper that had failed and quite literally dumped all the fluid out of the system. I didn't see any puddles or anything underneath the car once I got to the house - but a mechanic came and looked at it today and quickly found the problem.

Ended up replacing the caliper instead of trying to fix it - seems to be working OK now...but I must admit, it has left me a bit shaky about driving the ol' vette

7t9l82

i would do all 4 calipers they could easily be the same age

wombvette

You still should have had the rears though if that was the problem. They might not be great, but they should have been there for back up in that system.

LancePearson

If your car had a proportioning valve when the front went the rears should have been working and a dash light brake warning should have come on...that's what would have happened in my 76. Also, if your power brake booster unit check valve isn't working right it can do funny things too. However, if you found a leaking caliper that's probably the deal.

To affirm what someone else said...now that you have one new, powerful brake caliper on you might as well replace the other three and should have put new pads in both fronts anyway. While at it, put new hoses. You now have a system with one part newer and stronger than the other three and I'd be willing to speculate that you will now have three more failures in the not too distant future as new overpowers old.

Want to put five confederate dollars on it?

Lance P.

beernut

I'm a bit low on confederate dollars, sorry

I too thought about what you're saying - it only makes sense that the other three will fail sooner or later so they need to be changed. I'll check around town for prices - and will do some Googling to find good procedures (seems that the Haynes manual is not great on this particular subject.)

Also, the Brake warning light did come on after I mashed the pedal to the floor (not before.) If the rear brakes were supposed to be working, they must be utter crap - because the car had extremely little stopping power.

Btw, while we're on the topic of my car falling apart, do any of you have any recommendations on a new gas pedal/wire setup? The retainer (if you can call it that) on my gas pedal is junk and the wire keeps slipping out...

As always, thanks for the info and help from all of you - it is much appreciated!

noonie

You may want to take your calipers apart and see if they are already sleeved in stainless (which they probably will) and if so, then since you are over there a good choice may be just to kit them with pistons and oring kits for around 30 bucks each. Would save a bunch on shipping and core charges.
Orings may be a good solution if you have very long winters with the car sitting too.

LancePearson

You might also see what shape your rear pads are in though they are supposed to in most cases ride against the rotor so I'd think they would work even if fairly well worn. I can't remember the numbers but the front does a greater proportion of the breaking due to the weight,etc.

I can tell you how I know that once one part of the system with four key nodes like the brakes fails do them all. With a 76 bought last Oct. when one failed the front two were redone which lasted 9 months and once that was first done, then the rear two failed and we replaced the calipers, hoses, pads on the back. It was driven very lightly for five years by the p.o. and I drove it harder so things did get stressed more which revealed their weaknesses. Now have four new calipers with four new sets of pads and four new hoses, one new master cylinder whose diaphragm started to leak as well and one new proportioning valve and brake system finally works without lights or loss of function but I'd guess these are always going to be sensitive brake systems from reading the forum.

I should give the parking brake star adjuster an adjustment but since I don't live in San Fran and my key only comes out with the four speed in Reverse it just ain't worth the bother!