Old...rusty...brakes

[LanceB]

Well got the 75 and spongy brakes and brake light on. No fluid in rear portion of master cylinder. So get on jacks, wheels off and checking the bleeder valves. All open but one...now I am in a real pickle...it broke off in the darn caliper, figures. I tried getting the caliper off but rusted tight. I have changed the calipers on my 81 and bros 77 and I had problems (torching/penetrant an old stuck bleeder valve but it eventually came off), but not like this. I guess the good and bad news is the brakes have never been touched. I was hoping to bleed it, change all the bleeder valves and get fluid in it to see where/if leaks but now I am stuck. What can I do? I have to say re-threading the caliper for a new bleeder valve is a skill that is not in my vocabulary. I can turn a wrench and read instructions but I am not as advanced I need to be. And I think getting the calipers off is going to require some heavy equipment and more than me cranking on it.

If I could just get this valve replaced I could at least get it on the road. So I am looking for advice on re-threading and replacing the bleeder valve first (what about chips of metal from rethreading, do they fall in the caliper and will they be flushed out when bleeding?). If a new caliper is the best answer how in the world can I get this thing loose. I already torched, sprayed PB and cranked on the two bolts but they won't budge. I will offer this too: if anyone is in the Louisville, KY area I will pay you, feed you well and supply beer if you want to bring your expertise to my garage and we play horsepower TV for a little bit! But advice is very welcome.;help

 

[73shark]

I think that you'll have to get the caliper off to either fix or replace. The best penetrant that I've found is called Kroil and you get it from Kano Labs. That and some heat should break those pesky bolts loose.

KanoLabs.com

Getting the broken bleeder out can be done by using an easy out or by drilling most of it out and then picking the rest out. Probably have to clean it up w/ the correct tap.

 

[White75]

Been there and done that with our 75. More than likely your calipers are due for a rebuild/replace if they've never been done before.
To try and remove the broken bleeder, get yourself an easy out bit (any hardware store sells them) and use that to pull out the broken bleeder.

To remove the caliper, I soaked it in PB blaster (my fave) but it still wasn't enough for it. I hit the bolts with everything I could. I used a torch (scary given the amount of lube I had already used), impact wrench, and breaker bar. Nothing worked. I broke every socket I had that fit, including an impact socket (now that's hard to do). At that point, I had managed to round off the corners of the bolts. I was ready to weld a socket on there to break it loose. I instead went and got a bolt extractor kit (looks like a socket set and available at most hardware stores)and used that to grab onto the head. The harder you yank on that, the tighter it grabs which is a big benefit. I used the extractor with a breaker bar and the handle to my floor jack as extra leverage. I put all my weight on the long bar (total of about 5 feet of leverage) and heard a snap. Luckily the bolt broke loose but even if it had broken off, it would have released the caliper and it would have been possible to drill out the rest of the bolt) I figured it took about 900ft-lbs of torque to break it loose (your mileage may vary)
Hope you have good luck with yours.

If I lived near you, I'd definitely come to help since there's beer involved.

 

[LanceB]

Thanks for the advice guys. I figured I had a tougher one here and didn't understand why my torch, PB blaster and young whipper snapper strength didn't do squat like it did on my 81. That little bolt has kicked my butt, I feel like a caveman out there. I have been trying to turn it with just my socket set so I may as well had been hitting my head against a concrete wall with the progress that did.

Question on the breaker bar, would a 2 or 3 foot length of pipe (or longer) suffice or is there a specific "breaker bar" at an auto supply store (that may be a dumb question)? I see i need some serious leverage (and a good grip) and think this is the route to go in addition to the extractor. My only worries are the exact length of pipe/breaker bar to get the necessary leverage but still have room to work on these bolts in that wheelwell and under the car with just my floor jacks holding the rear up? The bolt closer to the cabin is definitely going to be tricky to get too but at least I have the garage floor to push against for more leverage on that one. Again thanks for the advice, this website is a lifesaver for owning these vettes. There is always someone else that had the same problem you did!

 

[White75]

yeah, old rusty bolts suck.
A breaker bar looks kinda like a ratchet without the ratchet mechanism. It's basically a handle with a U-joint at the end. If you try to put too much torque on a ratchet, there is a good chance of breaking it. Since there is no mechanism to the breaker bar you can really put some power down on it to break tough bolts.
You can use any length of pipe and it doesn't matter what kind you use as long as it's strong and fits over the breaker bar handle. Like I said, I used my jack handle which is about 4 ft long. The longer the bar, the more torque wil be applied (law of leverage) so for something real stubborn 3-4 feet is optimal.
I did mine with the car jacked up on jack stands (and wheels under the frame rails just in case it fell) and went after it from the rear of the car. There was just enough room between all the other stuff back there to reach successfully.

Thanks for the advice guys. I figured I had a tougher one here and didn't understand why my torch, PB blaster and young whipper snapper strength didn't do squat like it did on my 81. That little bolt has kicked my butt, I feel like a caveman out there. I have been trying to turn it with just my socket set so I may as well had been hitting my head against a concrete wall with the progress that did.

Question on the breaker bar, would a 2 or 3 foot length of pipe (or longer) suffice or is there a specific "breaker bar" at an auto supply store (that may be a dumb question)? I see i need some serious leverage (and a good grip) and think this is the route to go in addition to the extractor. My only worries are the exact length of pipe/breaker bar to get the necessary leverage but still have room to work on these bolts in that wheelwell and under the car with just my floor jacks holding the rear up? The bolt closer to the cabin is definitely going to be tricky to get too but at least I have the garage floor to push against for more leverage on that one. Again thanks for the advice, this website is a lifesaver for owning these vettes. There is always someone else that had the same problem you did!

 

[LanceB]

The breaker bar did the trick! I think I still need to torch and PB all of the bolts before i go cranking on them with that thing. Now just pondering whether to replace all calipers, or just the rears and do the fronts later (depending on what I find when I start bleeding it), whether to replace all rotors/none of the rotors...so many choices. Definitely think I should replace calipers in pairs at the least. I wish the front calipers had been the one the bleeder valve broker in because they get most of the load when you stop.

 

[TimAT]

For sure replace the calipers in pairs. I'd also look at replacing the flex brake lines while it's apart. They can fail internally and cause you a locked up brake. You can get calipers at Autozone, I hear they're all sleeved now. Sounds like your calipers are all pretty original. Mabe time to think about just biting the bullet and rebuilding the whole system. Do it once and be done. If you don't drive your Vette all the time, maybe think about getting O ring calipers too. They're a little bit more resistant to developing leaks. If you decide to go with stock lip seal calipers, check your rotor runout- too much runout will promote the seals sucking air and you'll be back to the start.

 

[LVMYVT76]

Replace ALL of them, your life is worth a few dollars. The front do most of the braking. You are going to have to bleed the brakes, so do it all at once.

 

[LanceB]

I went ahead and bought new calipers for all four. I also noticed the master cylinder top gasket is all warped and can't be reset so I'm replacing that too. I already have a new master cylinder too I never used on mine if that needs replaced. I purchased a motive pressure bleeder in the fall and it really helped with my 81 so I'm pumped up I get to use it again. Unfortunately temp dropped from 75 degrees this past weekend to 30 degrees and snow tonight so maybe finish wednesday. I sure wish I had a lift, I could put it up there and work on cleaning up my undercarriage now that I am looking at it with the wheels off and I see about a 1000 jobs I want to jump into.

 

[LanceB]

Well got all the new calipers on last night. I am still waiting on the rear rubber flex lines to come in, I already put new ones on the front. I went ahead and attached it and bled it. The new passenger side rear caliper won't do anything, no air, no fluid nothing! All the other calipers spit out the air, old fluid, then the new fluid with some bubbles, then the bubbles went away and they were all good. I went in order like the manual said. My motive bleeder is really nice. Also the new rear calipers has three bleeder screws on it, so I am not sure what order to do those in. I went inner to outer but didn't know which outer one should go first (it may not really matter). I am hoping just the rubber flex line is bad and after I replace that maybe it will start working. I guess all I can do from here is just keep replacing stuff and work my way up from the new caliper. Let me know what you guys think, I need to get this 75 on the road!

 

[73shark]

Try cracking the psgr side hose at the pipe connection nearest the master cylinder to see if maybe the hose is collapsed.

 

[JohnZ]

Also the new rear calipers has three bleeder screws on it, so I am not sure what order to do those in.

The rear calipers only have two bleeder screws, both at the top in the installed position; where is the third one you mentioned?

 

[minifridge1138]

The rear calipers on my 1982 have 3 valves.

1 inner on the top
1 outer on the top.
1 outer on the bottom.

 

[73shark]

Now that's interesting. Wonder what the third one is for? Not interchangeable w/ the fronts then are they?

 

[LanceB]

Well brakes are done. After replacing the flexible hoses in the rear everything was great. I had to bend some tubing to replace the short line from the flex to the caliper as well. Thanks for all the advice, no more brake light and they feel tight! Now time to move on to spark plugs and wires, change belts, flush all the fluids, blow out the carb, work on the convertible top, the list goes on and on!

 

[JohnZ]

Now that's interesting. Wonder what the third one is for? Not interchangeable w/ the fronts then are they?

Nope. The bore sizes are different - rears are smaller than the fronts, which is why the castings are different.

The bleeder at the bottom should be a plug - there was never a bleeder at the bottom originally.

 

[LanceB]

Ok I drove it to work today (top down!). Brakes feel real good. But brake light still comes on. I can pump the brakes and make it go off. I have replaced all calipers and the flexible hoses as well as the gasket on the master cylinder cover (it was warped). No visible leaks anywhere. I bled with my motive bleeder until clear fluid and no bubbles. What do you think I should check now?

 

[LanceB]

Turns out one of the new calipers I bought had a leak at the seal behind the pad. I took it back and everything is working great now!

 

[KANE]

Turns out one of the new calipers I bought had a leak at the seal behind the pad. I took it back and everything is working great now!

Good to hear!