Ineffective Parking / Emergency Brakes

cycleguy55 · #1 (**permalink**) 08-09-2019, 11:58 AM

I have searched the forums and a number of members are having issues with ineffective parking / emergency brakes, as I do. There seem to be few answers to the problem, however.

I've converted my rear brakes to GM 'large style' calipers with integrated parking brakes. The rear brakes work with the brake pedal, so they're not out of adjustment. The parking brake lever pulls up all the way (nearly vertical, FWIW) and the brakes actuate, but they'll barely hold the car on level ground, and won't hold it on much, if any, slope. I'm not happy with that. It seems to me the lever needs to pull more cable so the brakes actuate with less pull of the lever.

I have a West Coast Cobra, and the Kellison build manual I have indicates the parking brake lever is a Chevrolet Vega lever (yes, seriously). I don't know for sure that is what's installed, but looking at the lever there's definitely a resemblance to the hand-drawn sketch in the Kellison build manual (volume 2, page 05.30-3). It's kind of an ugly lever and I'm inclined to replace it with a Lokar lever (EHB-7000F).

Do all parking / emergency brake levers have the same cable pull / ratio? If the Lokar lever (or another make / model) has a different ratio that pulls more cable for a given amount of lever movement, then that may solve my problem. If not, then I'll likely need to fabricate something to increase the cable pull, along the lines of this: Emergency brake problem

I have not yet contacted Lokar, but may well do so - I just thought someone here may have the answer.

Thoughts?

SLP · #2 (**permalink**) 08-09-2019, 12:10 PM

If initial adjustment was done correctly, it sounds like just cable adjustments are in order. If you didn’t have the cable and spring off for initial parking brake adjustment that’s probably the problem. I went through all of this last week. It was frustrating, but I finally got it.

cycleguy55 · #3 (**permalink**) 08-09-2019, 12:47 PM

Quote:

Originally Posted by SLP

If initial adjustment was done correctly, it sounds like just cable adjustments are in order. If you didn’t have the cable and spring off for initial parking brake adjustment that’s probably the problem. I went through all of this last week. It was frustrating, but I finally got it.

Been through all that. Followed installation instructions 'to the letter'.

Worth noting is the lever worked fine with the old drum brakes.

spdbrake · #4 (**permalink**) 08-09-2019, 01:28 PM

Brian,

I take it yours are the GM metric spring loaded parking brake calipers? If so this initial adjustment may help.
https://www.littleshopmfg.com/conten...20GM%20C10.pdf

If not a handle with more throw should do it.
https://www.amazon.com/MagiDeal-Mech...omotive&sr=1-1

or
https://www.hotrodhotline.com/emerge...s#.XU3FWuhKiUk

Emergency Brake Levers | Parking Brake Controls | E-brake Levers

cycleguy55 · #5 (**permalink**) 08-09-2019, 03:49 PM

Quote:

Originally Posted by spdbrake

Brian,

I take it yours are the GM metric spring loaded parking brake calipers? If so this initial adjustment may help.
https://www.littleshopmfg.com/conten...20GM%20C10.pdf

If not a handle with more throw should do it.
https://www.amazon.com/MagiDeal-Mech...omotive&sr=1-1

or
https://www.hotrodhotline.com/emerge...s#.XU3FWuhKiUk

Emergency Brake Levers | Parking Brake Controls | E-brake Levers

The kit used is the MBM DBK9, and it looks like it uses the metric calipers (5.5" mounting hole spacing): DBK9- Universal Ford 9" Rear-End Universal Disc Brake Kit - MBM Brakes

I've been through the initial adjustments and the rear brakes work fine using the brake pedal - so calipers / pads are set. It's the parking / emergency brake that doesn't work. Even if the calipers hadn't been fully adjusted, the hand brake has been used enough the calipers would be adjusted by now.

Thanks for the links. The only one that looks like it may actually pull more cable is the MagiDeal setup from Amazon.com, but apparently none of the sellers ship to Canada. I've found the same lever on Amazon.ca, and I may well be ordering that setup. Even if it doesn't pull the necessary cable 'out of the box', the multi-hole lever that pulls the cable would allow for an easy extension that would give me what I want.

Thanks.

cycleguy55 · #6 (**permalink**) 08-25-2019, 10:20 PM

Okay, I have sorted it out. The cables were all fully adjusted and the parking brake operational when the brakes were changed, but it seems the various components have 'settled' after some use, creating some slack in the cables. My suspicion is the ends on the cables that hook into the equalizer bar are the main culprits.

Simple fix. A cable adjustment at the lever end was all it took. Having said that, the space in which to turn the adjuster bolt is somewhat tight, so it's about a 1/6th turn of the nut with each crank of the ratchet. It's a 5/16" NF thread, so 24 TPI. There were lots of pulls of the ratchet before I got it to where it seemed to be in the proper range. The brakes are now fully engaged with the lever about 40°-45° up from horizontal.

I'm happy now.

cycleguy55 · #7 (**permalink**) 08-29-2019, 09:32 PM

Well, I thought I had it sorted out. I had the car up in the air and had occasion to turn the rear tires by hand with the parking brake engaged. Passenger side was locked tight. Driver side, OTOH, still turned. WTH!!

To make a long story short, I discovered the brake arm that actuates the brake was missing the attachment nut. Gone. I checked the nut on the passenger side and it wasn't anywhere near as tight as it should have been. 7/16" NF? I thought these were 'metric' calipers! Bleeder screw takes a 7/16" wrench. Huh.

Anyway, replacement nuts were installed with blue Loctite, as the exposed stud isn't long enough for a nylock nut or lock washer. Shame on GM for that oversight, and shame on me for not installing them the first time with Loctite.

Moral of the story: Even when you think you've found the fix, check and double check to make sure.