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Old 18th December 2018, 19:41   #21
Eric_m
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The separate shoes on the 75 system is most of the problem, in my opinion. If, like most people, you only apply the handbrake when stopped, the shoes never really wear in. I've found that you really need to abuse the handbrake every now and again to clean up the shoes. When slowing down to traffic lights gradually apply the hand brake to slow you down (not with a 38 tonner right behind you though). Keep doing this, even pulling the handbrake on quite hard when you are on a quiet road, until you get a much better feel and grip from the back. Re-adjust and they should be much better.

Damm - Colvert beat me to it

Last edited by Eric_m; 18th December 2018 at 19:42.. Reason: too slow
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Old 18th December 2018, 21:11   #22
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I would apply the handbrake occasionally when approaching home, releasing it afterwards (I park on the level, after having a few cars' drums stick, with my Megane's delaminate because of its sticking in cold damp weather). Besides it allows any potential of heat distorting the drum (very unlikely) to dissipate.

The main reason for posting though is to have some mechanical sympathy when applying anything more than a gentle rub of the shoes to a moving hub. Especially with corroded back plates, it could damage them further and pull the pins through. It is only designed to be applied when stationary, not with a moving hub like cars with drum brake AND slave cylinders/pistons.
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Old 18th December 2018, 22:10   #23
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Originally Posted by clf View Post
I would apply the handbrake occasionally when approaching home, releasing it afterwards (I park on the level, after having a few cars' drums stick, with my Megane's delaminate because of its sticking in cold damp weather). Besides it allows any potential of heat distorting the drum (very unlikely) to dissipate.

The main reason for posting though is to have some mechanical sympathy when applying anything more than a gentle rub of the shoes to a moving hub. Especially with corroded back plates, it could damage them further and pull the pins through. It is only designed to be applied when stationary, not with a moving hub like cars with drum brake AND slave cylinders/pistons.
Actually, and not intending to be contentious, the hand brake is designed to be applied if for any reason the foot brakes fail.
With the double braking system this is unlikely but half the system working with the help from the hand brake will bring the car to a stop a little faster than just the half system on its own.

Maybe two feet behind the car in front and not 6 inches bedded in the back of it.---


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Old 18th December 2018, 22:19   #24
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There is MORE friction between POLISHED surfaces than surfaces that have been roughed up with emery or sand paper.
Agreed, so long as they do not have "glazed" high spots, which often happens with the friction material in new shoes aswell as rust high spots on the drum. That is the reason for the use of abrasive, to level the surface.
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Old 18th December 2018, 23:12   #25
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Agreed, so long as they do not have "glazed" high spots, which often happens with the friction material in new shoes aswell as rust high spots on the drum. That is the reason for the use of abrasive, to level the surface.
If you read my previous post you will see I recommend using both components to bed them together.

Never used abrasives on any of the cars I have owned that had drum brakes. They do their own levelling. Seems a lot of work to strip these things down to do something that will naturally occur during use.

Also brake shoes being of a softer material can end up with those abrasives embedded in their surface and cause premature and excessive wear of the drums.----
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Old 18th December 2018, 23:23   #26
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Originally Posted by COLVERT View Post
Actually, and not intending to be contentious, the hand brake is designed to be applied if for any reason the foot brakes fail.
With the double braking system this is unlikely but half the system working with the help from the hand brake will bring the car to a stop a little faster than just the half system on its own.

Maybe two feet behind the car in front and not 6 inches bedded in the back of it.---


I would still disagree, at least on our cars . The size and construction of the shoe is nowhere near the bulk of a drum only brake shoe, although, I dont think in the situation you describe would be much of an issue.

These two posts illustrate the size/bulk differences

ZT/75 drum

R25 drum

The design of our drums compared to a 'drum only' rear brake differs in that if the pins were to fail, if I recall, the only thing to stop the closed shoes rotating with the turning wheel/drum would be the handbrake cable attached to the expanding lever. In a 'drum only' brake, the shoes would be restricted by a substantial fulcrum point and/or the pistons from the slave cylinder(s) (see images above). If the pins failed on only one side of our cars, you run the risk of the shoe on that side locking up and causing a loss of the rear.

A dual circuit system is designed to operate diagonally, so using your handbrake could add unpredictability in a situation where you need that predictability (ie three operating brakes).

In saying all that, if I felt my brakes were not going to stop me in time, I would probably still reach for the handbrake lol. But I wouldnt try to lock it up. I have been in the situation where one of my circuits failed coming off a motorway slip road - on a first date, turned out to be a last date too lol. I did use the handbrake gently to assist in my braking, which (in my mind) relieved the pressure on the burst slave cylinder seal. In that non ABS car with disc drum brakes it worked well. I mention ABS as I suspect there could be some complication to its operation too.

edit: just had a look, it actually warns not to use it in motion in the handbook. Page 127

discovered a post whilst looking for drum images from the late Wuzerk HERE which explains something I always wondered, why the efficiency of a handbrake on an MOT was so low.
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Last edited by clf; 18th December 2018 at 23:58..
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Old 19th December 2018, 00:24   #27
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My handbrake was woeful and, upon examination, my discs were all on the way out too – so I got new pads, shoes, discs/drums all round.


Disappointingly, the handbrake was SHAYTE afterwards. Now, my last 3 motors were Beemers, with I think more or less the same brakes, and the handbrakes were all hopeless. An M3, and impossible to do handbrake turns… yes, OK, I know I shouldn't at my age anyway.


Anyway, I did a lot of the driving-with-handbrake-on as discussed above, then got it readjusted – MUCH better now than it’s ever been, working properly for the first time in the 8 years I’ve owned it. Still couldn’t do handbrake turns with it, but now I really AM too old, and can’t be NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- any more.


I suspect the design is {naughty word} but hopefully if you try the above it may help.
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Old 19th December 2018, 18:16   #28
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Interesting the page 127 in the hand book.


However I've found from personal experience it is necessary to lightly apply the hand brake from time to time, on the move, to maintain full efficiency of the brake when parked.

As you say it could perhaps induce instability if used in emergency however.

I have the choice to do what I do or risk failure at MOT time.----


All those bent up bits that have to be replaced are due to the excessive force needed to make the handbrake work.

Poor design springs to mind when reading about how many cars need the brake coupling modification. ( entirely due to the fact that when new drums and shoes are fitted they urgently need to bed in and match one another. )

The best and most cost effective way for the average driver to do this is as described above in previous post. ( I always do this and it always works. -- )

All the component parts in the hand brake system in my car are the original non abused parts. )

All of the above are my opinions and others may hold a different view. I am only describing what works for me.--

Last edited by COLVERT; 19th December 2018 at 19:14..
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Old 20th December 2018, 02:29   #29
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Handbrakes need to be adjusted properly.

I think its tight at the back, then 3 notches/turns slackened off.

Also RAVE sensibly recommends before embarking on any adjustments, to do exactly what other posters have said, which is to engage the brake, and drive for a short distance to clean the NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- off the drums inside.
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Old 20th December 2018, 15:33   #30
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I have repaired the compensator on both my cars as per the threads. Also new pads and discs but no other tweaks, they are both now perfect. Thanks to all who have contributed to this.
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