Emergency Brake

[74 Silver Bullet]

E brake doesn't hold on even a slight incline. Had the rear rotors off today and the adjustment looked good. I've adjusted the handle for a short pull and also for a long pull and neither seem to be any better as far as holding.

Any thoughts?

Thanks, Mark

 

[sfdon]

how about the eccentrics at the rear brakes?

 

[74 Silver Bullet]

how about the eccentrics at the rear brakes?

When I had the rotors off I checked the operation of the e-brake shoes and they were spreading apart upon e-brake handle pull. I did not disassemble the eccentric assembly.

The e-brake does apply a small amount of drag (indicating to me that the shoes are contacting the drums), but not enough to hold the car on a minor incline.

Do coupe e- brakes usually work well?

Mark

 

[Stevehose]

The brake should work to hold an incline. Did you rotate the adjusting wheel to take the slack out?

When I had the rotors off I checked the operation of the e-brake shoes and they were spreading apart upon e-brake handle pull. I did not disassemble the eccentric assembly.

The e-brake does apply a small amount of drag (indicating to me that the shoes are contacting the drums), but not enough to hold the car on a minor incline.

Do coupe e- brakes usually work well?

Mark

 

[Arde]

When I had the rotors off I checked the operation of the e-brake shoes and they were spreading apart upon e-brake handle pull. I did not disassemble the eccentric assembly.

The e-brake does apply a small amount of drag (indicating to me that the shoes are contacting the drums), but not enough to hold the car on a minor incline.

Do coupe e- brakes usually work well?

Mark

Car moves an inch before the e-brake does it thing and keeps it in place.
Everything looks good, like many other things in my life I could never figure out why so I stopped asking.

 

[lloyd]

In answer to your question, if you can't depend upon your emergency/parking brake - something seems amiss.

If I read your post correctly, you have rear discs, which, to the best of my knowledge, do not have eccentrics - { unlike early model E9's - i.e., 2800, which only have rear drum brakes.) It does consist of small shoes and internal drums that can be adjusted per photo in Steve's post. The fact that the shoes move outward to engage the drums is good but there is more to braking effectiveness than mechanical movement.

The handbrake should always be adjusted if the hand-brake lever can be pulled up by more than 5 notches on the ratchet. Insert a screw driver through the 15 mm (0.6 in.) hole and turn the adjusting wheel until the brake disc can no longer be moved. Then back off the adjusting wheel by 2 ÷ 3 teeth.

Aside from the actual friction material composition, braking efficiency can suffer if the friction material is worn, glazed or contaminated. Yes, this not only includes braking the car when moving, but locking the rear brakes for secure parking. Likewise, a severely worn or grooved drum surface can reduce friction material contact with the drum and thus limit braking potential. All of the above can result - after years of normal wear - or much sooner if one drives with the parking brake engaged. Thus. if you have not already done so, consider reexamining the shoes and drums and correct any obvious deficiencies. At the very least, examining the shoes for scoring, cracking and overheating is a good idea, followed by a light sanding and cleaning with brake cleaner. Although I doubt this is your problem, even parking brake shoes can bind against a brake backing plate, hence the reason for the recommended dab of molygrease.

Hth.

 

[m5bb]

E brake doesn't hold on even a slight incline. Had the rear rotors off today and the adjustment looked good. I've adjusted the handle for a short pull and also for a long pull and neither seem to be any better as far as holding.

Any thoughts?

Thanks, Mark

I have this same issue to a lesser degree.
I have new handbrake cables and have totally rebuilt each system with new springs and hardware and rebuilt calipers.

I did NOT replace the emergency brake shoes as they looked ok.

I think they are glazed over as suggested and just don't grip very well.
More parts to order?

Gary

 

[rsporsche]

why not rough up the emergency brake shoe surfaces? some nice 40 grit sandpaper. i was wondering if the surface had glazed.

 

[Stevehose]

I'd just replace them, they are inexpensive and easily available, there's a whole kit available with springs etc. Disassemble the adjusting and lever components, clean, and regrease. Clean the hubs. Then put the car on a lift or jackstands so that the car is just off the ground. Spin the wheels and adjust the handbrake lever cables so that each side grips the same amount at the same time and is fully locked by 6 clicks or so, and that the wheels fully release when the handle is down. Additional tightening can be done on the ground by turning the 10mm handbrake cable nuts equally.

why not rough up the emergency brake shoe surfaces? some nice 40 grit sandpaper. i was wondering if the surface had glazed.

 

[Peter Coomaraswamy]

If I may contribute a little, first, we'll assume that you have discs and thus the only thing that can be done is concentrate on the shoes "within" the discs. To satisfy the possibility that there is something amiss in the brake/cable/hand lever area, you may want to jack up the rear wheel(s) and with the car properly blocked front and back of the front tires and the e-brake off try spinning the wheel and then apply the hand brake and see if it stops- or makes it very hard to turn. If so there is only one place where the problem can occur and that is in the contact area within the disc. Because the shoes are pretty cheap and you already have the disc removed it would be good to replace the shoes at this point and the inner surface should be thoroughly cleaned and "roughed up" using some pretty heavy sandpaper. I would soak the sandpaper/emory cloth in brake cleaner and really go to town. You can use a wire wheel on the end of a drill as well. Old caked-on "spooge" can harden and build up in the groves and be very difficult to remove so you need to really clean it and rough up the surface. If you do a good job you should not need to have them machined, and don't worry about scarring the surface(s) the brakes only come in contact with the inner drums when the car is stopped (or when your master cylinder goes out traveling down a steep hill)- in which case scratched e-brake drums will be the least of your problems. These inner drums will still need to be adjusted per the instructions because if they start off too tight they could glaze the drum surface making your prior work all-for-naught.

I have done both types of brakes (drums and disc/drum) on e9's recently and the parking brakes work extremely well.

Hope that is of some help.

 

[m5bb]

I'd just replace them, they are inexpensive and easily available, there's a whole kit available with springs etc. Disassemble the adjusting and lever components, clean, and regrease. Clean the hubs. Then put the car on a lift or jackstands so that the car is just off the ground. Spin the wheels and adjust the handbrake lever cables so that each side grips the same amount at the same time and is fully locked by 6 clicks or so, and that the wheels fully release when the handle is down. Additional tightening can be done on the ground by turning the 10mm handbrake cable nuts equally.

Thanks guys just another item to ad to the list.
Gary

 

[74 Silver Bullet]

Thanks everyone!
When I had the rotors off and inspected the shoes, inner rotor drum, and mechanism, it all looked good, dry, un-scored, un-glazed, etc. I will however go back and rough up the shoes, and drums, and adjust as indicated in the manual. I'll follow up with the results.
Thanks to all, Mark

 

[Honolulu]

I had this issue with a '93 E36 convertible that was given to me a year ago - handbrake next to useless. The weekend before I sold it, jacked it up, took off the caliper, rotor retaining screw, and rotors.

Problem solved: the adjustment was far out of whack as I expected, and the lining on one of the shoes had disintegrated. Given the absolutely rotten condition of several areas of the car from previous owners, this was not unexpected.

SO.... remove handbrake lever boot, slack off the two nuts on each cable. Observe the direction of the adjusters on each wheel (they snug up in different directions). Reassemble rotors and calipers, then use a narrow screwdriver to run out the adjusters until there is drag, then back off a "little bit". Use pliers to pull the handbrake cables at the handle, and run the nuts down to the lever. Check for drag and back off the nut(s) if needed, then snug up the second nut on each cable. RESULT: handbrake holds the car on steep hills with four clicks.

You already went in for a look and things appear okay. I suggest a couple things... make sure when you pull the lever, that the cables actually move the lever inside the rotor. Do the adjuster thing at each rear wheel until there is drag when you try rotate the rotor. If it won't display drag, you may be adjusting in the wrong direction, verify (usually by removing the caliper and rotor again, ugh, wasn't once enough?).

To test, roll the car slowly backward and pull up on the lever. The side of the car that raises is tighter than the other side, adjust the cable length under the lever boot accordingly.

Even with no friction material on one shoe, I got the 'vert handbrakes nice and tight as they should be. I told the buyer of the situation and that a set of new shoes was about 25 bucks. No response in that area to date, several weeks later.

 

[jefflit]

I've worked on brakes, including drums, for decades but the e-brake shoe adjuster on my 3.0 makes no sense to me. Am I missing a piece here? There are three parts: A female barrel (no threads), a male barrel (threaded) with star adjuster wheel, and a clip that keeps the star from rotating freely. With that, I could spin the star until blue in the face, in any direction, but it won't extend because it isn't threaded into anything. What am I missing (or misunderstanding)?

Nevermind - I figured it out. I'm an idiot. The threads are in the star - it is two pieces. Both of mine were turned all the way in and I just didn't think it through. Doh.

 

[Honolulu]

Back again to this resurrected old thread.

Suggestion: since the brake shoes may now, or may have in a past life contained asbestos, use wet/dry sandpaper and plenty of water when cleaning brakes. I'd suggest anyone wanting to roughen their brake shoes use not less (numerically) than 100 grit, e.g., use 150 or 180 wet/dry sandpaper. Rinse well with water when done and allow to air dry.

I used to get calls when I worked in the environmental consulting business that went something like "I just bought an apartment and it has a popcorn ceiling. How can I tell if this is asbestos or not?" Sometimes the caller would say they'd scraped of half the ceiling before someone intervened (!) To which I'd reply "take a crumb of the stuff and grind it into a fine powder. Snort it and call me in 15 years." This is patently ridiculous and I'd get a moment of awkward silence before denying I ever would, could or did say something like that. Then the real advice "Take a crumb of the stuff in a pair of tweezers and light a match under it. If it burns up it's probably not asbestos. but if the crumb sits there glowing in the flame, you may have a problem and professional testing is suggested."

Can't catch fish without your hook in the water.