Hints and Tips - Brake Lining Materials and Performance

From: Mike Harris
Sent: 03 November 1999
To: British Cars Pre War
Subject: Asbestos in brake linings

I have been using modern soft bonded linings on both Austin Seven and Alvis 12/50 for several years now. They are much better than original asbestos linings. They bed in more quickly, can be bought in different thicknesses to account for wear or skimming of drums and require less pressure. The Austin 7 has two wheel brakes which actually are effective.

Mike Harris


From: Peter Thompson
Sent: 03 November 1999
To: british-cars-pre-war
Subject: Asbestos brake linings

The old car movement seems to be full of old pessimists and worriers. If it's not unleaded petrol, its anti-old-car legislation putting us all off the road, and now it's asbestos brake linings. Personally, I feel that the sooner all this stuff is destroyed the better. There is seriously predicted to be an epidemic of mesothelioma (lung cancer) due in a few years from the exposure of large numbers of people to even very low levels of asbestos dust, and I'd rather not be included. But then if they banned cigarettes, I suppose there'd be a few nutters desperate get supplies so that they could kill themselves smoking.


From: Graham Orme-Bannister
Sent: 03 November 1999
To: british-cars-pre-war
Subject: ASBESTOS IN BRAKE LININGS

There is proposed European legislation to ban the use of asbestos in brake linings. The directive is basically Health & Safety at work legislation and should not affect. what is done in private workshops. The legislation will however prevent any manufacture in Europe so that even if the private use is legal there will a problem with supplies. This raises several questions. 1. How critical is the use of asbestos in brake and clutch linings for pre war cars. What experience is there of more modern friction materials. The problems presumeably relate to using materials designed for servo systems in systems relying on leg muscles. 2. Does such legislation already exist outside Europe; US or Australia for instance. If so what has the experience been. 3. More a thought than a question. If private use remains legal, and if suitable materials are still being made somewhere else in the world, why should we not import privately. There must be a site on the Internet somewhere selling this stuff. Does anybody have a name.

Graham Orme-Bannister
Alresford, Hampshire, UK


From: Andrew Burley
Sent: 03 November 1999
To: Graham Orme-Bannister; british-cars-pre-war
Subject: Re: ASBESTOS IN BRAKE LININGS

My brother-in-law works as a project engineer at BBA Mintex and when talking to him about the shoes on my 1930 Standard Big Nine he said that they have non-asbestos equivalents for most original materials.

He said that he could provide something more grabby than the original if it was desired, but my own preference is to stick to the performance intended at the time as it was probably well matched to the combination of the torque for the large wheel diameter and trying to minimise skidding on narrow tyres. Contemporary road tests showed braking distances at low speed that modern cars would be hard pushed to beat. I managed to find a full set of new old stock Ferodo linings which will probably see the car through until we eventually get legislated off the roads completely.

I showed my brother-in-law an advert from 1935 for a particular grade of lining material used on buses and he came back to me a few days later with a spec sheet and an equivalent material number. Of course the availability of a suitable material is one thing - getting it in shoe form of the right diameter is another. There is a lot of old asbestos stock in the radii that are needed for vintage cars, but there aren't many new car-type drums above 9" diameter and therefore we are back to the old problem of needing to tool up for production of short runs for cars with larger brake drums. Companies like BBA Mintex and Ferodo will almost certainly still have the dies but the costs of putting them on to even a prototyping line will be quite high.

If the sale of old stock is prohibited, autojumblers will have to offload the stock to private buyers quickly before legislation comes in or face the cost of specialist disposal of asbestos material. Reality is that asbestos linings would become an under the counter commodity.
> 2. Does such legislation already exist outside Europe; US or Australia for
> instance. If so what has the experience been.

I don't know about this but I will ask my brother-in-law when I see him.
> 3. More a thought than a question. If private use remains legal, and if
> suitable
> materials are still being made somewhere else in the world, why should
> we not
> import privately. There must be a site on the Internet somewhere
> selling this
> stuff. Does anybody have a name.

I suspect that it will soon be illegal for any brand new car component to be supplied from outside the EU to an EU address unless it carries the dreaded E mark.

Andrew Burley, Yorkshire, England
1930 Standard Big Nine Fabric Saloon


From: John McEwen
Sent: 04 November 1999
To: british-cars-pre-war
Subject: Re: ASBESTOS IN BRAKE LININGS

I don't believe we have used asbestos in brake linings - or anywhere else for that matter - in North America for many years. The problem is a non-issue. As with unleaded gasoline, catalytic convertors, electronic engine controls and many other "innovations" in Europe, North Americans have dealt with the problems - in many cases more than a quarter century ago.

John McEwen


From: Charles Ping
Sent: 04 November 1999
To: Andrew Burley
CC: Graham Orme-Bannister; british-cars-pre-war
Subject: Re: ASBESTOS IN BRAKE LININGS

You commented...

"There is a lot of old asbestos stock in the radii that are needed for vintage cars, but there aren't many new car-type drums above 9" diameter and therefore we are back to the old problem of needing to tool up for production of short runs for cars with larger brake drums."

But there are commercials! A friend of mine always got new 16" linings for his 4.5 Lagonda made up by the garage that used to reline brakes on lorries working in local quarries. I can vouch for their efficiency but my recollection is that they weren't cheap. This was still a viable route a couple of years ago.

Lateral thinking!

Charles Ping


From: Bishop Peter
Sent: 04 November 1999
To: 'Mike Harris'; British Cars Pre War
Subject: RE: Asbestos in brake linings

Mike, I saw you comment about A7 two wheel brakes being effective and wondered what I am doing wrong! Now I have got my car on the road I have had a few scary moments due to the rear footbrake being fairly ineffective. The parts are all new and I thought may just need bedding in, but after 400 miles have not really improved. One thing I wondered, is do I need to shim out the shoes? There is a some movement of the brake levers (about 1/2 inch) before the shoes contact the drum, which I have currently taken up by adjusting the cable. Does shimming the shoes achieve anything different from shortening the cable? Also given that both pivot points for the shoes are fixed how do I ensure that both shoes contact the inside of the drum at the same time if I pack the shoes out with shims? Any suggestions welcomed before I run out of clean underwear or flatten some part of the scenery.

Pete Bishop
Swindon UK


From: Clive Sherriff
Sent: 04 November 1999
To: Bishop Peter
CC: British Cars Pre War; 'Mike Harris'
Subject: RE: Asbestos in brake linings

Message text written by Bishop Peter
>I saw you comment about A7 two wheel brakes being effective<

In my humble experience Austin 7 brakes - 2 or 4 wheel -are only effective when travelling at less than 10 miles an hour! and uphill at that!!!

Clive Sherriff


From: Bishop Peter
Sent: 05 November 1999
To: 'Clive Sherriff'; Bishop Peter
CC: British Cars Pre War; 'Mike Harris'
Subject: RE: Asbestos in brake linings

Conveniently it only seems to do 10MPH going up hills!

Pete


From: John McEwen
Sent: 04 November 1999
To: Barry Lovelock
CC: british-cars-pre-war
Subject: Re: ASBESTOS IN BRAKE LININGS

>John McEwen wrote:
>
>I don't believe we have used asbestos in brake linings - or anywhere else
>for that matter - in North America for many years. The problem is a
>non-issue. As with unleaded gasoline, catalytic convertors, electronic
>engine controls and many other "innovations" in Europe, North Americans
>have dealt with the problems - in many cases more than a quarter century
>ago.
>
>John McEwen
>
> catalytic convertors....
>
>I believe cats are inefficient over short (British) town-type distances,
>smelly and downright expensive to replace. They are failing at low milages
>even when used correctly. This may not be true with the latest sort
>however. Furthermore I read an article some years ago, endorsed by the
>major manufactuers saying that the correct way forward for Europe was the
>lean-burn engine, but only commercial pressures on government and
>(ignorant) legislators brought about cats for us. Lean-burn was on the
>back burner so to speak, but will have it's day.
>Anyone care to comment?
>
>Barry Lovelock.
>
>

Chrysler Corporation introduced lean burn engines in the early '70s. They were in use for a number of years and discontinued in the early 80s in favor of better technology which evolved to replace them - notably fuel injection which of course prescribest the correct mixture for all exigencies. Catalytic convertors have been in use from the same time and were initially less successful due to odour and cost. They are now reasonably priced and very effective - with modern electronic control systems and fuel injection. Note that computer control of engine/fuel systems has been in effect in North America starting in 1977 with modern fuel injection systems starting in 1975. Carbureted vehicles have not been offered for sale since about 1985.

The prospect of fitting catalytic convertors and lean burn systems to older cars is probably a very difficult and unrewarding process. Chrysler's lean burn still required electronic ignition, high energy spark systems and some forms of computer control. If the manufacturers in Europe are voting for lean burn systems it is only because they are cheaper - not better. I'm sure they can do much better than 1970s technology. Unfortunately, you are enjoying the fruits of having ignored the problem for too many years. European manufacturers have all of the technology in place right now - due to their having to conform to North Amercan standards for exported vehicles. Putting the same technology on European market vehicles is a non issue. They simply have to do it but won't until they are forced to by legislation and market pressures.

Here in North America we are now more concerned with how long we'll be able to drive vehicles which use gasoline/petrol as the energy source. I suspect that in less than 20 years this will not be the case as our energy sources will be natural gas, propane, and hydrogen. Try converting your Austin 7 to burn compressed natural gas. How about a Lagonda V12 running on propane?

John McEwen


From: Barry Lovelock
Sent: 04 November 1999
To: John McEwen
CC: british-cars-pre-war
Subject: Re: ASBESTOS IN BRAKE LININGS

John,

Thanks for your interesting and detailed answer. I believe the article I read was combining lean-burn with all the modern technology available and although not meeting the very latest regs was not far off. We too have no carburettor cars left now in production, it being virtually impossible to meet the emissions thus equipped. Cats certainly are expensive, 400+ for the cheapest though, the early prices were in the region of 1000 so things are improving. When I bought my Range Rover 3.9 litre (13 mpg (UK!)), I purposely bought the last of the non-cat ones. It would only be 12 mpg with the cat and 10 bhp less. I fear the day of the big engine is over, even for you maybe. Next year the new hybrid Honda goes on sale here, with it's 1000cc 3 cylinder petrol engine and a 10 kw electric motor, at 16000, it will give 80 mpg (UK). It looks like a pig IMHO, but will do 0-60 in 12 secs and have a top speed of 112.5 mph. I think the motor industry is currently in a strange situation, ever day sees the release of a faster, bigger vehicle - witness the new Mercedes flagships etc, but the speed limits are low generally and I fear the hand of legislation will fall soon....

By the way I did check the CO of one of my Austin Sevens - 8 %........ I could adjust it to about 2% or less but it wouln't run, or in particular pick up.

Barry.


From: Dee Davis
Sent: 05 November 1999
To: British-Cars-Pre-War; mike_harris
CC: deedavis
Subject: RE: Asbestos in brake linings

Peter,

Immediately remove the drums to guarantee that the linings have properly bedded in; that's crucial to the operation of cable brakes. If necessary, remove the shiny spots with sandpaper or a fine file, run the car and repeat the check.

The answer to the question about shimming vs. adjusting depends on the arrangement of the actuating cam and the lever attached to it and the cable end.

Dee


From: Stuart Ulph
Sent: 04 November 1999
To: Bishop Peter
Subject: Re: Asbestos in brake linings

Pete,

no doubt you will get lots of correct advice on this . Very good section on subtle brake adjustments in Chris Gould's latest edn. of "Building repro Ulsters", also no doubt you have carefully read Jack French in the A7 Companion. My own rough tips: easy way to see what contact you have on shoes - search in scrap box for lightly rusty drum. Fit this and apply brake gently by hand while rotating relevant wheel. Nice rust marks on linings show you where it touches and you can rub them off with fine sandpaper. Do not breath in asbestos dust, of course. You need a spare brake drum for Chris' method as well. Secondly - are you pressing the brake hard enough? If the mechanical advantage is poor - and the way you have set up your brake levers does not give the max. poss. thrutch - you can cheat. I can lock up all 4 wheels on my (OK, coupled brake) '33 tourer at 40 mph. They don't all lock at an absolutely identical moment but it is controllable! I do this by pressing the pedaL with my HEEL and straightening my knee. If you try this, I would start at low speed. Lock up both rear wheels of your Chummy at 40, one just before the other, and you might spin it then roll it! Or you might break the seat! I don't do this all the time, of course, anticipation is much better...If you really are stuck to see Chris Gould's book I suppose I could OCR the relevant para & e-mail it to you, but being lazy I'd rather not...Good luck, choose an empty road for the heel expt. , who knows which way the car will point!

Regards, Stuart.


From: Bishop Peter
Sent: 05 November 1999
To: 'Stuart Ulph'
CC: 'british-cars-pre-war'
Subject: RE: Asbestos in brake linings

Stuart & Dee, thanks for your replies on this , I will get busy with my rusty brake drum and sandpaper and practice breaking with my heel and trying to grape the handbrake at the same time! I have put Chris Gould's book on my Christmas list. Pete


From: Mike Harris
Sent: 05 November 1999
To: Bishop Peter
CC: British Cars Pre War
Subject: Re: Asbestos in brake linings

I forgot to mention that I have semi-girling brakes on my Chummy which allow for some adjustment. The problem with these is that the brake cams are at the wrong position whem on a Chummy. I have got two cams which have not had the grooves for the cotter pins filed in and when I get round to it will fit these to ensure the levers are at the right angle relative to the cable. However they still work very well but with a little extra pedal movement. But that doesn't help you!

Suggest you measure the drums to see if they have been skimmed and if so either put a strip of steel under the linings to bring them to the same diameter (or just slightly less) or get thicker linings. The trouble with skimming drums is that the diameter is greater than originally and the brake linings are, even when expanded only going to contact on part of the circle. So adjustment of cable will not alter the area of lining in contact. The shoes with linings ought to sit nicely in contact with the drum. Your brake levers should make an angle of just less than 90 degrees with the cable when the brakes are off so that when applied the angle is 90 degrees. This will give maximum effective leaverage. The other item to look at is the end of the shoe. The aluminium shoes wore where they contacted the cam. You can get a kit to put an end plate on these so restoring them to health. I bought one about 5 years ago at Beaulieu but can't remember who from unfortunately. This would have the effect of reducing the movement in your levers and restoring settiongs to as new.

By the way, all is not quite as rosy as it may seem. On our RTC Special the brakes work very well going forward, but coming backwards down trial hills they make a horrible noise. I have chamferred edges, lubricated pivots etc all to no avail. Any suggestions?

Mike Harris


From: Geoff Holmes
Sent: 04 November 1999
To: Bishop Peter; 'Mike Harris'; British Cars Pre War
Subject: Brake adjustment (was Asbestos in brake linings)

Pete,

I have a Riley 9, but I assume the brakes are of a similar design, and the following made an improvement to mine: adjust as necessary with the cable; slacken the pivots a turn or so; wedge the brake pedal down with something, or deploy a volunteer, and tighten the pivots again with the brakes applied. Shimming shouldn't make any noticeable difference. Hope this helps.

Geoff Holmes,
Oxenhope, Keighley, W. Yorks, UK.


From: Adrian Roger Twelvetrees
Sent: 07 November 1999
To: Geoff Holmes; Bishop Peter; 'Mike Harris'; British Cars Pre War
Subject: Re: Brake adjustment (was Asbestos in brake linings)

Dear listers,

Riley nine cable brakes can sometimes be improved by shimming behind the steel block that sits on the end of the brake shoe. The object is; first to ensure that both shoes make contact with the drum at the same cam angle, and second that the cam angles on all four wheels are approximately the same when the shoes touch the drums. No doubt when the cars were new and fitted with shoes from the same batch of castings this was not necessary.

Best wishes to all,

Roger Twelvetrees


From: David Cochrane
Sent: 08 November 1999
To: Pete Bishop
CC: british-cars-pre-war
Subject: Re: A7 brakes

Pete,
> The other item to look at is the end of the shoe. The aluminium shoes wore
> where they contacted the cam. You can get a kit to put an end plate on these
> so restoring them to health. I bought one about 5 years ago at Beaulieu but
> can't remember who from unfortunately.

Try Don Breakspear, telephone number sent direct.

David C.


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