'Old' brake friction material

[James_Russell]

Afternoon all,

I'm getting ready for the spring and making sure my car is tip-top (can't bloody wait!)

I have read somewhere in this forum that the performance of braking friction materials deteriorate with age, and that when replacing brake pads/shoes, 'old stock' parts which have been sitting around for years should be avoided.

A couple of questions, then-

Firstly, is it true that brake friction materials deteriorate with age (not considering risk of contamination etc)

Secondly, where do you suggest I get new rear shoes for my ital-axled car, which were manufactured recently?

Oh and finally, from a performance perspective, which is technically better- a thin slither of friction material or a massive wedge? I presume the answer will have something to do with heat conduction...

Thanks in advance, forum-goers.

-James

[Revin Kevin]

James,

Friction material doesn't really go off with age but number of heat cycles, more so if those heat cycles are near its limits. I find pads tend to go off before they wear out, probably due to the above.

As for Ital axle shoes, standard ones are available via Redline etc, if you want uprated Questmead will reliner your shoes in brand new uprated material, down side is you need to send them some old shoes and the cost is about double standard material.

 

Cheers

Chris

[Sheds Moderator]

Quoting James_Russell: 

Firstly, is it true that brake friction materials deteriorate with age (not considering risk of contamination etc)

No. I don't think it is, if it's clean and dry it works as well 20 years on as when it was new.

[pQuote]

...for my ital-axled car...

from a performance perspective, which is technically better- a thin slither of friction material or a massive wedge?

What's best? A disc brake. 😶‍🌫️

[JetSepter]

You'll never stop if your friction material slithers like a snake - you want at least a sliver, like a bit of cake! Sorry! Couldn't help myself. Pedantic, I know. (Cross refer to Chit Chat thread 'Can we have our language back?' which I didn't start.)

[James_Russell]

Chris- thanks. I'm expecting my current shoes may be as old as the car is, so I think new ones may be in order (although they do still have about 3mm at the leading edges). They're also marked 'EBC', and I've never once been happy with one of their products!

BOSS- I wouldn't consider replacing the shoes so prematurely on an ordinary car. But this one is a Racecar the same reason that unfortunately I can't just get a dedion chassis or a disc brake conversion. For what it's worth, with the ordinary road tyres we have to use (even when 'hot') I've never had a problem locking the rears (after the fronts, thankfully!)

JetSepter- Call yourself pedantic? You didn't even notice that I had incorrectly hyphenated 'forumgoer'

[Archie Procter]

Babybish - the rears only do around 25% of the braking on your car. Get some decent front pads and new discs, and just leave whatever you have at the back. FWIW I always just ran the standard Caterham shoes until they wore out, and I've got boxes full of trophies to show I was right to do so 😬

[Bricol]

I used to think age didn't matter. Then, because of a leaking slave cylinder, I replaced the rear shoes on the Dutton trials car.

 

Suddenly we had working rear brakes - which on a trials car with a distinct rear weight bias, has to be a good thing.

 

Now it might not be age, and simply a compound thing, but . . .

 

Bri

[elie boone]

James, just sand the disc surface with a P40 or something similar coarce sanding paper and also do the pads and they will be as good as new.

[Sheds Moderator]

If going the route of sanding it with a bit of abrasive paper, you should ideally use garnet paper. This doesn't leave abrasive particles on the things you have just sanded so you don't carry on abrading when you use the thing.

 

Having said that, a disc brake picks up rubbish from the road so there are always abrasive particles, so I wouldn#t get too hung up about it. Road dirt isn't carborundum grit though, that does have a particular ability to grind.

[elie boone]

Forgot to add : rince with brake cleaner