Help! Changing brake calipers and Emergency brakes:

[401KVet]

Ok, I'm not a mechanic, but I'm going to attempt to do this myself. I am changing all 4 calipers and rear pads. Since I'm installing new rear pads I guess the rotors should be turned. I know the rivets will have to be drilled out, and since the rotors are coming off, I figured this would be a good time to repair the emergency brakes with a new kit, cables and all.
I'm not looking for a step to step from anyone. But if anyone would have a Trick of the Trade they would like to share, or any surprises that may await me that I should be aware of, I would be greatfull. I have a 1980 Corvette Shop Manual, a Assembly Instruction manual, and a current Chilton 63-82 Corvette repair manual.
I hope I'm not biting off more than I can chew... LOL

 

[Vettehead Mikey]

Do NOT turn the rotors unless they actually need it. 99% of C2/C3 rotors don't. They are not routine service items like modern cars, many owners find the original rotors outlive the rest of the cars untouched. Don't attempt to fix what's not broken.

Asking about 'surprises'- do a search and see the nasty 'rotor runout' surprise that await people that wade in without doing their research.

BTW- if you're not sure when the rear wheel bearings were serviced, that should go on your list of tasks too. The e-brake could wait till then to get done.

 

[Hib Halverson]

Mikey's right.

Don't turn the rotors unless:

Runout is excessive and....know that runout in the rear can be a combination of wheel bearings and rotors so you need to determine to what the runout is attributed before you make a decision to drill the rivets and cut the rotors
or
They have grooves or scratches which are deeper than .015".

If there's no issue with runout or grooves, just change the pads and flush the system.

Now...if the rotors are under the minimum thickness, they must be replaced.

 

[Whiteshadow89158]

If the rear-end hasn't been serviced before, I would stick with the brakes until your ready to overhaul the rear suspension. I went in there only to replace a couple of bushings and the deeper I got, the more problems arose. In the end I was left with a whole new rear suspension lol. Make sure to install the calipers before you connect the brake lines because the pistons are really hard to compress afterwards. Just a tip for when you need to change your pads again, loosen one of the bleeders and you should be able to compress the pistons with your hands. Also when you bleed the system, start with the left rear, then right rear, then left front then right front. And the order that you open up the bleeders is front inside, rear inside, front outside, then rear outside. 4 bleeders per caliper. Don't forget to bench bleed your MC.

 

[401KVet]

Thanks:

I worked for NAPA for 8 years starting in 82. All of the brakes clinics they sent me to said to always turn the rotors anytime a new set of pads went on. BUT, apparently a older Corvette may be a exception. Yes Mikey, I have read what you said about C3 rotors. I'm going to leave them alone. The rear rotors look to be in good shape, no scaring. Not sure about the thickness. I don't have the tools/caliber to measure it. Man, you'd be surprised that in a city to size of Baton Rouge you can't find anyone they really knows how to work on the older Vette's. Some claim to, but when I start asking question's about rotor runout, they don't have a clue what I'm talking about. Even the dealerships are only up on the new stuff. One reason I decided to try and do this myself. I don't think the rear end has ever been serviced before Mr. White. I purchased my 1980 3 years ago with only 42,700 miles on it. Now has 52,000. I took a couple of long trips. The one brake problem that I did address right off the bat was the front rotors were warped. You know what that does to the steering wheel when you brake. So, new rotors and pads.
I think I'm going to back off doing the emergency brakes, and just changed all calipers and brake lines to the calipers. Keep the same pads on the rear. They still have pleanty left on them. The rest will have to wait. Maybe in the spring, after I do some more reading. LOL Thanks to all for the help and tips....

 

[Vettehead Mikey]

I worked for NAPA for 8 years starting in 82. All of the brakes clinics they sent me to said to always turn the rotors anytime a new set of pads went on. BUT, apparently a older Corvette may be a exception. ...........The one brake problem that I did address right off the bat was the front rotors were warped. You know what that does to the steering wheel when you brake. So, new rotors and pads.

Two things-

1) 'always turning rotors' is an old out-moded way of thinking. Turning rotors never made much sense back then, even less sense now, Corvette or not. It simply grinds away expensive metal. Garages use it as a 'cya' excuse or profit driver.

2) your front rotors were most likely not warped, just had an accumulation of pad material that could have been removed with an abrasive wheel. 3M makes a kit expressly for this common issue.


Why are you changing calipers?

 

[401KVet]

Why:

Two things-

1) 'always turning rotors' is an old out-moded way of thinking. Turning rotors never made much sense back then, even less sense now, Corvette or not. It simply grinds away expensive metal. Garages use it as a 'cya' excuse or profit driver.

2) your front rotors were most likely not warped, just had an accumulation of pad material that could have been removed with an abrasive wheel. 3M makes a kit expressly for this common issue.


Why are you changing calipers?

The Chevy dealership said they were warp. anyhow. After installing a NEW master cylinder and booster, the same problem started reocurring. Soft peddle and brake light comes on. This guy that claims to know old Vettes helped me bleed the brakes. All good for a few weeks and then the same thing over. Bleed, all good for a while, and then again. He said I needed to replace my lip seal calipers and that would solve the problem. Well the other day I was bleeding the right rear inside, and I pulled off the bleeder screw. I don't know why it seemed to be froze with all the bleeding going on. I took the caliper off and tried a EZ out, but no success. So I decided to go with his recomendation and change all to the O ring type.

 

[Vettehead Mikey]

You may want to measure rear wheel bearing play. Much over .008" play as measured on the rotor surface will have the same effect as rotor runout, air drawn into the caliper and a soft pedal. Do that before you spend money on calipers.

 

[401KVet]

Ok, Thanks for all of the help...

 

[401KVet]

Flushing brake system

You may want to measure rear wheel bearing play. Much over .008" play as measured on the rotor surface will have the same effect as rotor runout, air drawn into the caliper and a soft pedal. Do that before you spend money on calipers.

Bleeding all 4 calipers, and Flushing brake system.
What is the difference and how would you flush brake system??

 

[Whiteshadow89158]

Bleeding all 4 calipers, and Flushing brake system.
What is the difference and how would you flush brake system??

Bleeding the calipers means to remove air from the system. Flushing the system means to remove all of the old fluid and potential unwanted particles in the fluid. You can buy a fluid pump at an auto parts store for this task. All you have to do is attach the pump hose to the bleeder nipple, open your master cylinder cover and have a friend fill the MC while you pump the fluid out to prevent air from getting in the system. An alternative for this is to detach the rubber brake hose from the calipers and let them drain into a bucket while feeding the MC. People use this technique to gravity bleed the calipers but I'm sure it can be used to flush the system as well.

 

[401KVet]

Bleeding the calipers means to remove air from the system. Flushing the system means to remove all of the old fluid and potential unwanted particles in the fluid. You can buy a fluid pump at an auto parts store for this task. All you have to do is attach the pump hose to the bleeder nipple, open your master cylinder cover and have a friend fill the MC while you pump the fluid out to prevent air from getting in the system. An alternative for this is to detach the rubber brake hose from the calipers and let them drain into a bucket while feeding the MC. People use this technique to gravity bleed the calipers but I'm sure it can be used to flush the system as well.

Do you attach the pump hose to the bleeder nipple on each caliper and do this to all 4 calipers?

 

[Whiteshadow89158]

Do you attach the pump hose to the bleeder nipple on each caliper and do this to all 4 calipers?

Yes.

 

[401KVet]

Yes.

Is there a way to flush the brake system without sending the OLD brake fluid thru the new calipers I am going to install?
Thanks to all again....

 

[Hib Halverson]

Is there a way to flush the brake system without sending the OLD brake fluid thru the new calipers I am going to install?
Thanks to all again....

Flush the system.
Install new calipers
Bleed the system.

 

[401KVet]

Flush the system.
Install new calipers
Bleed the system.

HIB, that's what I want to do, but everything I've been reading tells you how to bleed the system, but nothing on how to flush the system. They say you should flush brake system before you install new parts, etc.. and that's it. I'm trying to find out what's the best way to do just that. Flush the Brake System...
Thanks for all help...

 

[Hib Halverson]

Imagine flushing as a sort of "extended bleeding".

When I flush the system, I first suck the old fluid out of the master cylinder and refill it. Then, I start at the RR caliper and bleed not just until the air bubbles are gone but until the fluid runs clean. I do the same at the LR, then the RF and finally the LF caliper. The fluid coming out of the calipers should look as clean as what you pour out of the can.

 

[401KVet]

Imagine flushing as a sort of "extended bleeding".

When I flush the system, I first suck the old fluid out of the master cylinder and refill it. Then, I start at the RR caliper and bleed not just until the air bubbles are gone but until the fluid runs clean. I do the same at the LR, then the RF and finally the LF caliper. The fluid coming out of the calipers should look as clean as what you pour out of the can.

Gotca. Just have someone pump the brake pedal as you would bleeding the brakes, but for a longer time until fluid runs clean.. I'm sure I will have to keep refilling the MC as I do all four calipers right?????
I just read something on gravity flushing. Are you familar with that method??

 

[Vettehead Mikey]

Flush the system.
Install new calipers
Bleed the system.

Remove as much of the old fluid from the M/C as possible, add the new then do what Hibs suggests above.

 

[Hib Halverson]

Gotca. Just have someone pump the brake pedal as you would bleeding the brakes, but for a longer time until fluid runs clean.. I'm sure I will have to keep refilling the MC as I do all four calipers right?????

I'd refill the master if it runs low but you'll find that if you siphon the old fluid out of the MC first and refill it then flush the rest of the system. You won't have to add that much fluid.

I just read something on gravity flushing. Are you familar with that method??

Yes. It works but takes a really long time.

Actually, I use a Motive Products pressure bleeder to flush and bleed. It allows one person to do the job in a short time.
See: Motive Products