Everyone seems to know that the C3 parking brake is rubbish. On my 1974 it has failed its annual test in the UK, not even getting to the 17% efficiency minimum requirement.

I have adjusted the brakes via the screw on the drum and taken some slack out of the cable at the point in the middle under the car.

I am concerned it still will not pass a re-test as it still feels spongy.

Any ideas on how to get a better parking brake performance without the tedium of a total strip down of the parking brakes.

Any advice would be appreciated.

Regards, Graham

 

Mine also failed the yearly inspection last time after renewing all the parts and adjusting it properly, I was lucky enough that they passed it exceptionally because its a classic car, but I doubt they will do the same thing next year.

C3s parking brake are simply POS. Now I quit trying to make it work, instead I'm looking for a way to retrofit a newer parking brake design into my car and throw all the stock components in the trash.

 

Mine has worked fine since the day I installed all new components. It has been working OK for years. I would not want to have to rely on it stopping from 60 mph but it holds the car fine and when a little power is applied it works. Not the greatest setup but done right they will work.

Make sure if you have new shoes in there that they are "broken in" properly. You have to burnish the pads first.

 

I did some reaearch into C3 e-brakes last month because I was having a hard time with vehicle inspection. It seems that the best way to adjust the e-brake is to disconnect the half-shaft to eliminate driveline friction. The e-brake shoe drag can then be adjusted much more accurately. I didn't disconnect the half-shaft but I did jack up the trailing arm so that the half-shafts were almost parallel. I was suprised by how much more I had to tighten the adjuster from what I thought was the max setting. Next year I am going to disconect the shafts and re-adjust the brakes properly before inspection.

As stated above, you also need to burnish the new e-brake shoes for maximum effectiveness.



Rick B.

 

Make sure your e-brake system doesn't look like mine did when I tore into it. No adjustment in the world that's going to make this work. I replaced with a SS system but don't have the wheels on the ground yet. Anxious to see how well they are going to work.

 

I'm not sure what you mean by "17% efficiency", I've never heard of anything like that for testing a brake.

If the thing just doesn't grab, there is a problem. Most likely, one or more of the shoes is stuck. To unstick a shoe, jack up the rear of the car and take off the wheels. Pull out the clip on the brake line where the solid and flexible lines meet. Unbolt the caliper and lift it up out of the way (I used a piece of coat hanger wire to suspend it). If your rotors are original and have never been off the car, they will be riveted on and you will have to drill out the rivets. Most likely, the rivets will be gone (they were on both my cars), so you can just pull the rotors off. Now you have direct access to the e-brake guts, and you probably haven't suffered much pain yet (the caliper bolts can be tough, but you'll get them), and you will be able to see exactly what you are dealing with. Most likely, the brake will look like the picture above, and you can try to free up the shoes without taking the mechanism apart.

If the shoes are moving freely, have someone pull slowly on the handle and count how many clicks you hear from the pawl until the shoes start to move. I going to guess by what you wrote, it will be 16-20. In this case, you will need to adjust more at the saddle so that you start to move the shoes by the 8th click or so. Your cable may be too stretched such that you run out of adjustment before you are engaging properly. In this case, you can add a short piece of pipe (like 1" long 3/8" diameter) and a washer between your adjustment nuts and the saddle, effectively lengthening the threads by an inch.

If you have to rebuild the brake, don't worry all that much. The stainless steel kit and shoes aren't that expensive, and the job can definitely be done by the weekend mechanic in a weekend. Let's put it this way, I have found my way through that job twice now, and both times, the e-brake has worked perfectly when I was done.

Good luck!

 

Just a quick note about this assembly here (since people search on this stuff all the time), this brake is missing its upper return spring.