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Discussion Starter #1 (Edited)
I've read loads of posts regarding the handbrake on our cars.

I've also adjusted a mine a few times and also some other BMW's with varying degrees of success.

With mine, I've always stuck to the recommended method (backing off 12 clicks at the wheel adjuster) but I've never had great results. I live on a hill, so a good handbrake would be handy!
I've replaced both cables, so there's not an issue with these.
I've replaced the shoes (I was given them with the car), the originals were ok but as I was 'there' I thought I may as well change them over. When I did the work I stripped everything down, cleaned and lubricated them (pivot and shoe/backplate touching points).

At the moment I have a handbrake that can just about hold, but I have to pull up hard on the lever. I'm not particularly impressed with this. My other (little) car has a similar setup and works ten times better, as does my wife's car. I can't see why BM should have such a poor parking brake.

When adjusting I do find that the LSD is a bit of a pain! It connects both wheels to such a degree that it's not always apparent which wheel is offering resistance. I find this when I'm setting the cable tension. To overcome this, I set one side's tension first, then back it off a couple of turns carefully so that I can then set up the second side's tension, then re-tighten the first side the couple of turns. On its recent MOT the rears were within 15% of each other's holding power (120 vs 140 on whatever scale they were using). I believe a little adjustment at the cable will improve this.

I've adjusted my mother's 318ti in exactly the same fashion, it has a fantastic handbrake which requires little effort at the lever end to obtain an effective wheel lock.

My father's 320cd is a different story, much like mine. Again, using the same 'correct' method, his is pretty close to useless unless you pull up hard on the lever, it's not how it should be.


So, I've been thinking about this problem and what might be possible to do to improve things...



What are the main parts?

1. The handbrake lever.
2. The handbrake cables.
3. The expander (Expanding Lock in parts listings)
4. The adjuster.
5. The brake shoes.
6. The drum (The drum is within the bell/hat section of the rear discs. On solid discs I believe the shoes work on the casting, on floating discs - ie Euro ones, there's a metal insert, steel or even stainless-steel, bonded to the aluminium bell/hat that the shoes work on).



How does it work?

The handbrake lever pulls on the two cables, transmitting the applied force to a expander at the top of the drum housing for each rear wheel. The handbrake can only pull the cables a certain small distance, so good adjustment it important.
Also, the brakes are independent. One side can be working whilst the other could be completely slack. This is not the case with several other manufacturers, as they utilise a balancing setup which ensures that both sides get the same force, often with only one cable at the handbrake lever.

The expander is at the end of the handbrake cable. As the cable is pulled, it causes the expander to open. As the expander is stuck against the shoes, it pushes the top of the shoes apart and in so doing, presses the friction material against the inner surface of the drum. If all is well, the shoes will press sufficiently to lock the wheel.

The expander is little more than a glorified bellcrank, more on that later...

The wheel adjuster, at the bottom of the shoes, sets the shoes at the correct distance from the drum. The procedure of opening the adjuster until the wheel cannot be moved, then backing off 12 clicks (or teeth) should ensure that the friction material is not in contact with the drum but is within 'striking distance.' It should also set both sides equally.
This in turn dictates how much the expander needs to move to get the shoes/friction-material against the drum.

When we adjust the cables (with the handbrake lever up two clicks), we are in effect opening the expander until it's pushing the shoes sufficiently against the drum that it is just possible to turn the rear wheels with some resistance (this is quite subjective, but as long as both sides are the same, I don't think it should make a difference). Releasing the handbrake allows the expander to close, enough to back the shoes from the drum.

Raising the handbrake lever when it's in use should pull a bit more, three or maybe four clicks, which should lock the wheels.



What can affect how the handbrake works?

1 Adjustment. At the wheel adjuster (at the 6 o'clock position), at the handbrake lever and in balancing; ie getting both brakes to work as hard as each other. It's imperative to slacken the cables at the lever and then get the wheel adjuster set correctly, THEN adjust the cables.

2. Cables. Perished cables will not allow as much of the lever's force through to the shoes.

3. Friction material. There needs to be a sufficient amount on the shoes. It needs to be in good condition (not glazed). It needs to have been bedded in to the 'drum,' so that it matches the curvature, allowing the maximum amount of material to be in contact with the friction surface.

4. General condition of parts. Nothing offering resistance where it shouldn't be, such as rust or stiffening due to dust build up.

5. Force applied to the handbrake lever. I believe that this should be quite low. Not everyone is a muscle bound hero able to rip the handle from the floor. A reasonable tug should hold the car securely on most hills (Isn't there a 'test hill' at some testing centre? I'm sure I saw an episode of TopGear where they tested various handbrakes on old British cars). I know that 'a reasonable tug' is subjective, but my wife can easily park her car on our hill, there's no way she'd be able to get the BM to stay there safely!



What can be done in addition to good adjustment?

Most of us have played around with the adjustment in attempts to improve the handbrake's performance. It would have been interesting to have experienced their performance when new, feel, number of clicks, holding power etc.
I'm confident, like many of you, that I've adjusted both the adjuster and the cables correctly and that they're 'not far out' but the performance remains disappointing.
I've yet to carry out the following, I shall do them in the next few weeks. I would like your input regarding my thoughts.

1. Double check the adjustment. Like many things, there can be a little wear and we may have made a mistake. Going back to the car and adjusting it all again will be much easier the second time around as you will know where to look and what to do.

2. Set the shoe position after adjusting the adjuster. Working on the adjuster can move the shoes a bit, giving a false reading. Working the handbrake (as is stated in the instructions) should settle the shoes back to their working positions. I'd be inclined to drive the car around a bit, to make sure everything is in place properly.

3. Bed the brakes shoes in well. I would have presumed that the oem shoes would match up well to the inner surface of the drum. I'm now not so sure. If the arcs of the shoes does not match the shape of the drum, only relatively small regions of the friction material will be in contact. Maximising this contact area should improve things.

The only certain way to ensure that the shoes offer as much friction material as possible to the inner drum surface (ie maximise the contact area) is to wear the friction material down so that the shape matches. As this will no doubt require modest removal of material, I would suggest temporarily changing the setting on the adjuster to about 9 or 10 clicks backed off.

How to bed the shoes in? The manual (DIS) says to lift up the handbrake whilst travelling at about 20mph or so for a few yards (I haven't read up on this, sorry guys, but I'm sure it's something like this). This would obviously be for the oem shoes, which you would hope, would match the drum size closely and possibly have a different compound. Non oem, pattern parts might need more work! I think that the relatively short distances mentioned is to reduce heat build up. Those of us with the Euro discs might need to think more of this, as the friction surface insert might not react well to too much heat (aluminium/steel have different expansion rates, it might be bonded in position and the bonding agent would not like too much heat etc etc).

I don't know the friction material properties. As it's only a handbrake that's not in use whilst driving, I would imagine that the material's compound would be very soft and grippy, so a short bedding in period would be suitable. If they were to be in use whilst driving, I would imagine that they would wear out rapidly.
On the other hand, they may well be pretty ordinary, run of the mill 'rear brake shoe standard' friction material that should really get more of the bedding in procedure. I have no idea and would welcome any input.

I'll try the bedding in a few times, ensuring that they have cooled down properly.

After this bedding in, I would say that it would be quite important to re-adjust the setup again, completely. I'll certainly go through it again as carefully as I can.


I mentioned earlier that the expander is little more than a glorified bellcrank.
A bellcrank allows a linkage to negotiate around a corner, usually through 90degrees. The expander has the cable (input) entering it at 90degrees to how it expands (output).
With bellcranks, you can get a mechanical advantage (or disadvantage) effect. In the central, neutral position, moving the input a certain distance will move the output a similar distance.
Moving the input closer to the extreme end of its range, a certain input distance would result in a much decreased output distance moved; however the flip side of this would be increased force. (Work done is equal to force applied multiplied by the distance moved. Work done is a constant, distance moved decreases therefore the force must increase).

The '12 click back off' stipulated by BMW should set the expander at its optimum position with regards to how much it needs to move to bring the shoes up to the drum and how much force it apples to them once in position.
Reducing the clicks significantly could increase the force required (at the handbrake lever) required to hold the car and the lever would need fewer clicks to lock.
Conversely, increasing the backed off clicks might mean that the shoes don't reach the drum surface (or you would need to adjust the cables more often) and the lever would give more clicks to lock position.
As I said, I think the 12 clicks back gives the best compromise, as I'm sure BMW would have experimented with this to achieve the best setting. It's the same system that they've used for generations of cars and different series' and it hasn't been changed (up to the e46 at least, I don't know about the newer cars).


All this thinking of levers and linkages got me thinking of the handbrake lever mechanism itself. I wondered if this offered greater force the more it was pulled up. This would have meant that the cable path would be closer to the lever's pivot(fulcrum) when the lever was pulled up high, but further when the lever was down (or at rest).
As it happens, I have a spare mechanism and I had a good look at it. It turns out that the lever mechanism offers no mechanical advantage. The cable path remains a constant distance from the pivot, so there's no advantage in slackening the cables to allow the lever to come up further, they will be pulled exactly the same distance. All the adjustment at the lever really does is allow for both cables to be balanced and the height of the handbrake lever.
This also means that the power of the mechanism is dependant on the setting of the adjuster (12 clicks) which in turn affects the expander. Get this sorted and it should perform at its best.


Just for the record, here's the official adjustment technique (copied from Valley Motorwerks' post in another thread, I hope you don't mind):
020-25 MAINTENANCE

The parking brake system is independent of the main braking system and may require periodic adjustment depending on use. Adjust the parking brake if the brake lever can be pulled up more than 8 clicks.

340-22 BRAKES

The parking brake is a drum system integrated into the rear brake rotors. It can be adjusted with the wheels installed, although the rear wheels will have to be raised off the ground.

- Lift the parking brake lever boot out of console. While holding cables stationary, loosen parking brake cable nuts until cables are completely slack.

- Raise rear of car.

- Remove one lug bolt from each rear wheel. Turn road wheel until lug bolt hole lines up with parking brake adjuster [dead bottom, ie 6 o'clock position]

- Using flat-bladed screwdriver, reach into brake drum through lug hole. Turn brake adjuster until wheel no longer turns. Back adjuster off 12 notches.

- Working inside the car, set parking brake several times to seat cable. Then pull parking brake lever up 2 notches. Tighten cable adjusting nuts until it is just possible to turn rear wheels with slight resistance.

- Release lever and make sure rear wheels turn freely.

- Turn on ignition. Pull up parking brake lever 1 notch and make sure that parking brake warning light comes on. If not, adjust parking brake warning light contact switch.

- Install parking brake lever boot. Install road wheel lug bolts. (Tightening torque road wheel to hub 89+7 ft-lb)

I hope that all of this will get your minds working and ultimately allow us to crack this problem once and for all.

I look forward to your views and discussion.
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Well, as a lot of the Z cars are coming out of their winter hiding spots, we are seeing a lot of handbrake concerns.
I alone had 3 this week.

My way:

loosen cable slack adjusters until there is 3mm (+-) of daylight between the big nut and the e-brake lever
set lever into "down" position (dis-engaged)
remove rotor (obviously all associated parts too)
inspect for seized parts (looks like you have, and then some)
disassemble, clean and lube if necessary.
sand shoes with 80-grit paper until light gray in color
brake-clean shoes, let dry.
inspect drum, if there is a rust ring buildup, sand it down. clean with brake-clean. let dry
re-assemble parking brake mechanism

**this is the important part**
the actuating lever that is responsible for spreading the shoes needs to be installed so that the "finger" that attaches to the cable is oriented in direction of rotor/wheel rotation. This allows duo-servo geometry to work for braking effect.

install rotor with grub-screw (6mm allen head) **leave caliper off)
tighten shoe adjuster until you can not rotate rotor
I then back the adjuster off 3-5 clicks
rotate rotor, if there is resistance, back off 2 clicks
repeat until rotor spins freely

once both parking brakes are set:
...take out cable slack at the handbrake lever by:
tightening the bigger nut **one side only** until you feel increased resistance.
pull of hard and quick on the lever 3-5 times
re-inspect nut, is there space between the lever and nut? if so tighten and pull up on lever 3-5 times.
no space? good. disengage lever (full down)
now spin the rotor of the cable you just adjusted.
do you feel any resistance?
no - good, tighten the jam nut (smaller one) whilst holding the large one. repeat above for other side
yes - loosen nut until it is gone. still feel resistance? make sure shoe adjuster isn't at fault.
*this should give you 5-7 clicks on the lever*


After cable slack is adjusted, re-assemble rear end, test operation.

this allows me to stop a z-car on our parking garage incline from a 10-15mph roll.


**note**
this process is truly based on feel. if in doubt, have a professional take a look.

-Pat
 

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Wow, this is a lot of information on the parking brake. When my car was getting serviced I had my friend/technician put in new OEM/ATE parking brake shoes because the old units didn't seem to hold the car in place that well. I also drove for a few miles with the dan brake up just a tad, which I'm sure was not good for it, heated it up, & put a great deal of wear on it.

The funny thing now is the fact that I have to pull the hand brake lever up substantially more then I use to have to. Shouldn't I have to pull up on it a lot less then before (since the parking brake shoes have been replaced & are brand new units)... ?
 

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Just adjusted my handbrake for the second time and would like to point out a couple of things.

After locking up the wheels using the manual adjusters, I backed off until the wheels turned free on both sides.

It was 3 pushes with a flat blade screwdriver......maybe equating to 4 or 5 notches.

I was trying to back off the bare minimum to allow a full free rotation.

The lever felt good so I didn't adjust it.......a roadtest revealed the handbrake was excellent.

The tip of the screwdriver has to move down to lock the right adjuster, and up to lock the left adjuster.

The adjuster is located just to the rear of the 6 o'clock position and down a bit.
 

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Discussion Starter #5
Thanks for reminding me of this.


I've since adjusted my handbrake three times.


First time was: slack cables then tighten drum adjusters all up and slacken them off four clicks. Re-adjust and balance cables.
This gave a reasonably good handbrake but I hoped for better. I tried bedding the shoes in by slowing to a stop from a slow speed a few times.


Second time: I went completely the other way, slacking the drum adjusters by 20 clicks. Adjusted cables again. This again gave a non impressive handbrake, probably worse than before. Doing it this way used up most of the adjustment at the lever.


Third time: I slackened the cables again, tightened the drum adjusters until wheel could just about 'not move' and slackened the adjuster off 13 clicks. I reckoned that with the wheel off and only working on the disc/drum, I would not tighten the adjuster quite as much to stop the disc from turning and 12 clicks back would be ideal (think about this, if you use enough force you can keep on turning the adjuster a few clicks, but the wheel remains locked; I just got the wheel locked and backed off 13 clicks). Reading the BMW method I noticed that they described correct cable adjustment when the rear wheel can 'just' be turned with 'slight' resistance (a bit contradictory but it is a translation I suppose). I took this as: it was all correct when the wheel could be moved a bit but it had a good amount of resistance, with the handbrake lever at the second click.
Done this way I have a reasonable handbrake. It remains less effective than I would like but with a good tug it will hold the car on my hill, just. It's the best yet!

To be honest though, there seems to be little difference between the number of clicks at the wheel adjuster. I believe that as long as there's enough room for adjustment (ie in the middle of the range) and that both sides are working as hard as each other, then you will have the best handbrake you can.

I might try to keep on bedding these in to see if the shoes grip a bit better. No doubt I'll be re-adjusting again in a few weeks! HTH.
 

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It's my opinion that the less you back off the manual adjuster, the more effective the handbrake is......it seems to allow better leverage at the shoe?
 

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Discussion Starter #7
It's my opinion that the less you back off the manual adjuster, the more effective the handbrake is......it seems to allow better leverage at the shoe?
It may well be the case but I feel that balancing the cables is far more important, so that both sides are pulled on as much as each other, or are working as hard as each other to contribute to the braking.

I suppose the best way to get this done would be to use the MOT brake tester and adjust the cables until both sides give the same reading. This would mean having access to a brake tester.
 

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i'll try to explain this in words and use the OEM parts pic as ref' for others
RealOEM.com * BMW E39 M5 PARKING BRAKE/BRAKE SHOES

"PHakes" got it about spot on... it is about feel in as much as getting the linings to match the inside of the drum
look at it this way,
with this set up there is no leading or trailng shoe as it does not need to slow the car so need not grip the drum under force/heat expantion

what you need is to find the centre point of each shoe and make the adjustment of said shoe bellow this point (slightly wider towards drum with #6) and as close as you dare, then adjust the cables (#5) to do the work ie: make contact with a couple of clicks on the handlever

basics: your looking to get the whole shoe (or as much as 90% of it) grabbing the drum when the handlever is pulled, this is where the feel comes in

-----got one question tho'?
bedding in the shoes? how are you doing this and why?
ok, doing it, you may think your getting larger contact surface but what you will have is smoother linings with less grip (stick)
bedding in is only any good if it is to be used as a propper brake, as when used under load the heat will make it expand thus creating more brake force on drum.... roughing up the suface of the shoe lining will give a little extra grip (drum also if you want)

if you have been driving the car and pulling on the handlever in the understanding that, this is beeding in?
then all that is doing is taking the shoe linnings out of shape to the inside of the drum and making the problem worse
you will never be able to get the whole sufaces to meet as all your doing is wearing the tops of the shoes if not adjusted spot on! (which impossable i might add)

easy to check tho':
take drum and shoes off and put shoes inside the drums on the bench/floor....push the bottom of the shoes (where adjuster would be) out and see if the whole surface meets the inside of the drum?
you may find that from about the center point (as above) up to where the cable conections are we will be out of true..(ie: a growing gap) if so bin'em and get your wallet out and off for a trip to you nearest car parts shop (about £20) should do it.
you don't need the all singing and dancin' stealer shoes.

keep adjusting, it will come, i have two clicks on my lever but it did take a couple of attempts to get right

( oh and 6 years of practice on my previous car e39 530 yawnnnn )
 

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Guys, I'm trying to do the parking brake adjustment and cannot for the life of me find the adjusting screw. I know it's supposed to be at the 6 o'clock position but all I see is a spring.

I pushed the flat bladed screw driver past it but do not at all feel a slot driven adjuster.

Does it really click when you move it?

I assume a clockwise turn is needed to tightened it up so the wheel no longer moves and then you back off right?

Please help. I'm desperate and I shouldn't be spending my birthday doing this anyway lol.
 

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You move the blade end of the scewdriver down to lock the right wheel, and up to lock the left wheel.

It's difficult to see if you've left the wheel on.

The adjuster is just to the rear of the 6 o' clock position and slightly down.

Also, I tried to back the shoes off a bare minimum to allow free wheel rotation.....

......The handrake was much more effective after this.
 

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Thanks so much chowdah and Scott. I thought I was truly screwed as I thought I over-tightened the right rear and it was stuck for a while however I was trying to loosen it the wrong way. As a result, the other side couldn't turn as well and the hole no longer lined up with the adjuster sprocket so it was a wtf omg bbq fml moment!

Got it done and better than ever!
 

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I'm the same....usless hand brake boat.
Got new shoes, placed then in, did wheel adjustment for normal free spinning out back.
Checked on the "clicks" made some adjustments and ran out of thread and added some 1/2" spacers to give me extra take up.
I've got StopTech brakes and the only thing I can think of is a stretched cable, or a poor circular match between the OEM shoes and the bigger StopTech inner hat shape and this is only giving me 10-25% of what I need.
Currently I couldn't spill a hot coffee on full lift at 10mph.
Glad I live in FL.

Apples
 

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I'm the same....usless hand brake boat.
Got new shoes, placed then in, did wheel adjustment for normal free spinning out back.
Checked on the "clicks" made some adjustments and ran out of thread and added some 1/2" spacers to give me extra take up.
I've got StopTech brakes and the only thing I can think of is a stretched cable, or a poor circular match between the OEM shoes and the bigger StopTech inner hat shape and this is only giving me 10-25% of what I need.
Currently I couldn't spill a hot coffee on full lift at 10mph.
Glad I live in FL.

Apples
I would guess a stretched cable in your circumstance.

Funny thing, after all the time I spent on Sunday on adjusting the damn thing, it felt pretty much the same. Later that night, I tightened the nuts a few more turns at the hand brake and it definitely has a more solid feel when I pull the brake but I also think I couldn't spill an over filled coffee by pulling that thing at any speed. I haven't tried but I think all it would do is slow me down very gradually.

I will likely raise the rear again, remove a lug bolt from each wheel and move each side one notch to tighten them.
 

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It really clicks (the click is the movement of the wheel against the spring which lays on top of it). I can't remember which way is tight, but you will be able to tell after a few clicks
 

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It really clicks (the click is the movement of the wheel against the spring which lays on top of it). I can't remember which way is tight, but you will be able to tell after a few clicks
Absolutely- blade end of the scewdriver down to lock the right wheel, and up to lock the left wheel.
 

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I found my original shoes from the car when it had about 4,500 miles on it, so I decided to put them back on.
I took the aftermarket Pep Boys ones out and they seemed a pretty good match when I compared them.

As you can see the shoes fit perfectly inside the hat, I just wonder if it's the alloy on the friction material that is the weak link, cast iron might have a great co efficiency of friction?.
The drivers side had piles of dust in there as you can see.
I did try and run them in months ago and that would be the pad debris... (that didn't help them improve)

I adjusted the bottom wheel so I could get the rotors on with ease and then adjusted the wheel to give me just the first grade of freedom from the rotor.

Not had a chance to test it yet.

Will get back on that topic.
 

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Can someone post pics of this DIY? Im starting to feel incompetent since i can't seem to get any more performance out of my handbrake save makingg it harder to pull. Any help would be appreciated, thanks!
 

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What sort of pics do you want.
What brakes do you have.

I've given up on getting anything decent to work.
I think it's because I have aftermarket brakes.
If I get what would be considered a normal lift on the hand brake (say 3-6 clicks) and 6 being the most I can get physically apply then I've done my job.
The only thing can be that when I give it a good pull (don't say it) and we'll call it 100% I'm only getting 25% on the brakes.
Its aftermarket or the knuckle isn't opening enough?

Apples
 
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