Parking Brake Question

I had PMB rebuild my calipers earlier this year, and in my case I only needed to readjust the calipers once they were installed. I did not need to adjust the cables at all. Of note, I had a functioning emergency/parking brake prior to having the calipers rebuilt.

 

I don't know what to tell you...I've had my car for 39 years and no dealer, no restoration shop etc. was able to make the hand brake work adequately. My restoration shop adjusted it to the max and I still can't get it to hold on a grade of even 2 degrees. It appears the cable has stretched over time or ? I don't know if snipping a piece of cable would provide more tension. I keep a rubber triangular wheel stop in my car and will place it under the wheel. Funny how old tech works even today. Good luck, and if you find the fix let me know and I'll buy the beer.
PS I know this is of no help, but I had to vent a bit...

 

I would be curious if your rear brakes work at all since the adjustment of the calipers for the parking brake to work properly is adjusting the pad position for normal brake usage. Do you have a consistent wear pattern on each side of your rotors? If they are working normally outside of the parking brake, your cable is probably problematic or needs further adjustment

 

It's a cable problem, as my brakes were totally rebuilt during the refurbishing...the cost to run another cable was deemed a waste of money as replacement didn't seem to make a difference in holding the car.

 

There are several points of adjustment in the parking brake system.

Starting at the handbrake handle ,you have a cable that goes to a the arm holding the pulleys. The pulleys tighten the adjustable cable that pulls on a caliper lever which moves the piston in. Then you have the actual adjustment of the brake pistons which fine tune the clearance of the brake pad to the disc. This last measurement is a standard clearance measured with a feeler gauge.

The handbrake handle should catch at about 3 or 4 clicks. You can adjust this by loosening the clamp at the end of the cable where it connects to the puller lever assembly. This is a course adjustment and may take several tries. Make sure the cable moves freely.

The next adjustment is when the pulley lever assembly moves and put tension on the cable that connects to the caliper lever that moves the piston in. This adjustment can be the key to the system working. First of all, test to see if the two, long adjusting assemblies will move. Loosen the lock nut and see if the assembly will now turn. NOTE: one is a left hand thread and the other is right handed. This allows the cable assembly to either lengthen or shorten. There is a good chance they won't turn. I had to replace my whole cable when I did my brakes. Although the main purpose of this cable assembly is to pull the pistons, I noticed that the cable has to pull the pistons a tiny amount even when the brake is off. In effect, the cable is under tension, pulls on the piston and immediately moves it when the lever is pulled. When the brake is in the off position, the caliper piston lever should be under tension. There should be no play in the cable. The trick is to keep the caliper levers pulled out a bit so they keep the cable under tension. You can achieve this by adjusting the two adjusters to either lengthen of shorten the cable. With the caliper levers already a bit out, any movement of the cable should immediately move the piston. When you have them somewhat working, you can now adjust the piston in or out to the specification using a feeler gauge.

With the above adjustments, your pistons should immediately move out when you pull the handbrake. If it catches too soon (like after one or two clicks) slightly loosen the handbrake cable where it joins the pulley lever assembly. This will determine how many clicks it takes to fully set the handbrake. You should not have to adjust the adjustable cable that connects to the piston lever once you get those levers under tension.

Regarding rebuilt brakes from PMB, I noticed that once installed and bled, they still felt a bit sloppy. I spoke to Eric and he said that the new seals are more elastic and will push the pistons out much stronger than the old seal. They do eventually "relax" and have a solid feel.

 

Just did this 6 months or so ago after I also had my calipers rebuilt by PMB. Replaced all 3 cables at the same time.
With the car lifted and wheels removed, there is a procedure, which I think I found on this forum, for adjusting the inner pad to rotor clearance using a feller gauge (.008" I think, don't remember exactly). That should be the first step, as this determines how much the lateral cables need to move to clamp the inner pad against the rotor. Then I adjusted the lateral linkage cables to the point the rotors just started to make noise, with just a light drag. I did it this way after I figured out that allowing the suspension to droop increases the tension in the lateral cables as they traverse up and through the bushing attached to the chassis. Once back on the ground, there was no sound or drag detectable when rolling the car. When starting with new cables, as I did, you also want to adjust the initial lateral cable lengths to have the lever arm for the lateral cables reasonably positioned relative to the main cable guide tube so the main cable motion is in line with the guide tube during it's travel. Finally I adjusted the main cable length allow the clevis pin to be inserted. The new cable was several inched too long, btw. Then I did it two more times (and counting) as initially my interior lever was practically pointing at the roof. It's now not pulling up so much, and I've used the parking brake enough that I'm thinking the cable is at its final tensioned length.

It now holds on a modest slope, though the design is still weak (pulling the handle only moves the inner brake pad). But I can pull it out of the garage and set the brake while it's warming instead of using a wheel chock. When leaving the car, I still park it in gear for the extra security.

 

I have had PMB send me back calipers missing missing the previously present internal parts required for the parking brake.

If the calipers are not correctly adjusted, no screwing around with cables will make the hand brake work. The design sucked big time but it can work.

One of many reasons I have a 328.