Brake Problems

[MR. T.]

I just got my 77 out of storage and have to do the work for the safety. I have just starrted working on it and already problems. I can't remove the front rotors that I need to replace! I drilled out the large flat head of the rivet and have tried everything I can think of to get the rotor off of the hub, nothing works, have soaked with penetrating oil and have tapped with a hammer, but they are seized solid. Any Advice?

I have also discovered a leak of transmission fluid, may be the pan gasket, but I will investigate further, as well the parking brakes is in bad shape, rear cable is seized and the left rear is also seized (much rust.) I am sure I will be back looking for more assistance, thank you to all how reply.

 

[Vettehead Mikey]

Why are you changing rotors? This is a big mistake 99% of the time on C2/C3 Corvettes.

Do a search on 'rotor runout' and you'll see why.

 

[Hib Halverson]

It is true that rotor replacement is sometimes not necessary but I'd disagree that it's a mistake 99% of the time.

Let's start at the "beginning"....why do the front rotors need to be replaced?

 

[MR. T.]

They need to be replaced as the have deemed them to thin to pass the safety inspection. So if I want to license the car I have to replace them.

 

[Hib Halverson]

Ok. That was the piece of info which was neeed.

You need to remove the rotors and hubs as a unit. Then use a drill press to drill out the rivets. You may also need to use a hydraulic press to separate the hub and the disc.

You can also try a really good penetrant such as Kroil or Aerokroil for 24 hours, then, with the hub/rotor assy off the vehicle, try using a BFH to knock the hub out of the rotor.

You may also need to press the studs out of the hub so you can abrade or machine the hub flange to remove all rust and scale.

Next, you need to do a trial assembly of the rotor and hub using the lug nuts installed upside down to hold the rotor on the hub. Then, you need to use a dial indicator to check rotor runout. This will tell you if the hub flange is 90° to the axis of the hub. If you have runout, try rotating the rotor on the hub to get minimum runout.

If it turns out that there is no way to get under .002 runout, you may need to have the rotors machined on those hubs to get the brake plates 90° to the hub axis.

As you can see, with C2/C3 disc brakes getting the hub flange, the rotor mounting flange and the brake disc all parallel is tough.

That's why, GM suppliers for hubs, axles and rotors, riveted the rotors to the hubs and the rotors to the axles and then they machined the rotor sufaces.

 

[MR. T.]

I got looking at it last night and realized the rivet was larger than I thought so a large bit and a couple of taps woith a punch the the rivets popped out. Th passenger rotor came off easily the driver side needed a little penetrating fluid and a couple of taps to get off. I will check the run out.

I ran into another problem with the parking brakes, on the driver side, they are corroded and seized, and on the passenger they are completely gone, as in I think they were removed. I am wondering where I can get a schematic for how they go together, I have checked my shop manual and it tells you what it should look like but doesn't show you, and I can't seem to find it in my assembly manual. I assume I need to order a complete kit including pads, but I want to see what else I may be missing before I start ordering.

Thanks for now.

 

[73shark]

Might try Stainless Steel Brake Corp. They sell a complete stst parking brake setup and also sell a stst parking brake cable and housing.

One reason the PB fails is infrequent use which allows the cable to rust (usually happens after the rubber boot on the end of the cable housing fails and lets moisture/salt in) and get bigger. Then when the PB is applied, the cable moves and applies the brake shoes. However due to the rust, the spring isn't strong enuf to release the stuck cable and then the brake shoes are used up.

 

[LanceB]

Unfortunately I don't even have a parking brake. Some idiot put too wide of tires on the back 6 years ago and this is how he remedied it. Unfortunately that idiot was me. The parking brake was in pretty rough shape anyway; I always planned to reroute the parking brake brackets and re-install everything but the time just gets away from you once the little guys come into the picture.

 

[petes74ttop]

Parking brake help www.corvettemagazine.com/technical-articles/c2/107-corvette-parking-brake-rebuild.html
Transmission leak might just be the gasket at the fill tube. PG.

 

[MR. T.]

Thanks for all the input. I am going to order the stainless parts and put it back together. I am a little baffled at how it goes together, in particular the actuating mechanism, that goes through the dust shield. Does teh shield play an active role in the brake? The reason I ask is that the hole through which this lever appears to go is a little misshappen, so the question is should I repalce teh dust shield as well? and how much additioanl work is that going to be. Thanks