mundo

My '84 had a hard time stopping with new rotors and good brake pads. Now my '92 Vette has a hard time stopping compared to my C5. Is it just my 2 C4s or is it a common problem in C4s?

Moon86

On my 85 your supposed to use the e-brake to keep the rear discs in adjustment. When I first got the car there was some spotty surface rust on the rear rotors that didn't go away until I started using the e-brake. Car also started stopping a little better. So now, when I back the car out of the garage, I use the e-brake to stop it. Also, after I started using the e-brake I had to put brake fluid in the master cyl. You might want to check that out.

dogfish246

My C4 brakes like its about to go off the end of a road into a deep ravine!

jhammons01

The '84 brakes are good...but there is always better.

Look into doing the C5 brake swap. it is a simple adapter plate bolt on. You'll need C5 or newer wheels as the 16" wheels do not have the I.D. to accommodate the larger caliper and rotor.

BADDUCK

Another option is 13" fronts and metallic or semi metallic pads all around.
I have that on my 1989 and they work pretty well. Not sure about if you would need different wheels on a 1984.

Aardwolf

Are C4's under braked, no. You probably have poor pads, also there could be issues with the pad not bedded in. And lack of maintenance. I've worked on the stock brakes and didn't have a problem getting them to lock up the tires. Try pads from Carbotech, new brake fluid, and do maintenance on the calipers.

jhammons01

^^Well, lemme ask....are you saying that you've seen brakes that "Never" lock up??

I've only got mine to go off of.....but I mean....Mine will lock up...it's just a matter of pushing that pedal hard enough.

Are there cars out there that won't do that? (I'm not questioning that what you say is true or not......I really have no knowledge about one that wouldn't skid the tires...and I am hoping to learn)

So yeah....if one wouldn't skid the tires...I'd be really concerned. When folks ask if they are under braked......I just assume their pedal is a little too hard for their taste to get to that "skid" level. OR, they are taking the car to the track and running through pads really quickly.......Those are the two things that come to mind when I hear these questions.

And for the sake of discussion, I buy the $20 brake pads from Kragen that are only sold online and shipped directly to you.....

RedLS1GTO

C4s aren't under-braked for a car that is almost 30 years old... but compared to most modern sports cars, yes.

darkstallion_69

I have the stock brakes on my 94 and it stops like a gem.

mundo

I have to push really hard on the pedal sometimes to get the car to come to a stop. They're not soft or mushy. Could the master cylinder or vacuum canister be bad?

Aardwolf

When I got my car it wasn't well taken care of. I don't know what pads were on it but they couldn't put down much braking torque. If I pressed the pedal as hard as I could it wouldn't skid, it would just come to a stop. I've got Hawk HT-10 on there now and they are really to much for street tires. Very light force is required to skid the tires.

Aardwolf

I've heard some say that the C4 is under boosted. IIRC FSM states 84 lbs of pressure on the pedal for full boost. I think it's fine but I'm a pretty strong person. A high hard pedal without much stopping power is a classic symptom of a damaged booster. I doubt your M/C is causing any issues but rebuilding it with new seals wouldn't be a bad idea for any of these cars at this age.

runner140*

The system has to be in good working order and the pad compound is very important.

I use Hawk HPS which are a ferro-carbon compound......light to medium dusting and very good bite (stopping power).

jhammons01

^^Yeah, but isn't the hot setup for later years is to get the Steel diaphragmed '84 booster vs the cheaper later years??

If that is the case, wouldn't the later years be complaining after putting an '84 booster on their car?

If the car or brakes don't grab, I'd first check the vacuum to the booster.

383vett

If you've got new rotors and new brake pads, it's going to take some miles to get them bedded in. The brakes have to conform to the rotors. My 84 stops very well from 125mph a few times a week. Well enough to make the first turnoff at Infineon!

PLRX

Did you bed the brakes? Or Did you install new rotors and pads and that all it was done to the system?


From 60mph, gently apply the brakes a couple of times to bring them up to operating temperature. This prevents you from thermally shocking the rotors and pads in the next steps.

Make eight to ten near-stops from 60mph to about 10-15 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS. At the end of each slowdown, immediately accelerate back to 60mph and then apply the brakes again. DO NOT COME TO A COMPLETE STOP! If you stop completely and sit with your foot on the brake pedal, you will imprint pad material onto the hot rotors, which could lead to vibration and uneven braking.

The brakes may begin to fade after the 7th or 8th near-stop. This fade will stabilize, but not completely go away until the brakes have fully cooled. A strong smell from the brakes, and even some smoke, is normal.

After the last near-stop, accelerate back up to speed and cruise for a while, using the brakes as little as possible. The brakes need only a few minutes to cool down. Try not to become trapped in traffic or come to a complete stop while the brakes are still very hot.

If full race pads, such as Hawk DTC-70 or Performance Friction PFC01 are being used, add four near-stops from 80 to 10 mph.

After the break-in cycle, there should be a slight blue tint and a light gray film on the rotor face. The blue tint tells you the rotor has reached break-in temperature and the gray film is pad material starting to transfer onto the rotor face. This is what you are looking for. The best braking occurs when there is an even layer of of pad material deposited across the rotors. This minimizes squealing, increases braking torque, and maximizes pad and rotor life.

After the first break in cycle shown above, the brakes may still not be fully broken in. A second bed-in cycle, AFTER the brakes have cooled down fully from the first cycle, may be necessary before the brakes really start to perform well. This is especially true if you have installed new pads on old rotors, since the pads need time to conform to the old rotor wear pattern. If you've just installed a big brake kit, the pedal travel may not feel as firm as you expected. After the second cycle, the pedal will become noticeably firmer. If necessary, bleed the brakes to improve pedal firmness.

BrianCunningham

stock pads are cr@p

get a decent set of pads in them

T. Wayne Nelson

I have an 85. I knew that the brakes were verly adequate, but, when I installed C5 z06 brakes, it was like night and day. So my answer has to be C4 brakes are not enough. I would stongly urge every C4 owner to do the swap

Aardwolf

You may also need to re-bed the pads if the rotor rusts on the fire path, that's very common around here. It doesn't take that many stops to see the pad material on the rotor. I've found four stops to be enough, YMMV. You don't need to do so many stops that there is fade, that's just setting you up for having to bleed the brakes or break down the pad material from over heating it.

mcm95403

Anyone know if the C5 conversion will work with the 17" sawblades? (sorry about the simi-hijack)