Brake pipes

Rust, obviously.

Poor quality plating? or heavy exposure to salt if near the coast or used on heavily salted winter roads. Most likely the former IMO. AFAIK, OE brake pipes are made from MS tubing with a light plating of zinc. If the plating is too thin, corrosion will attack it sooner. Mike.

Less obviously perhaps, damage caused by driving over something or damage caused by ham-fisted repairs?

All assuming the OP didn't mean brake hoses of course :-)

Chris

over zealous mot tester

Corrosion of the Standard-fit steel pipes, replace with kunifer.

One might also ask why manufacturers don't fit nickel based tubing like Kunifer which will last a helluva lot longer? I know it's more expensive, but would only adds peanuts to the price of a new car, and save many older cars from an premature grave. Mike.

My last three cars all had plastic coated steel brake lines. Unfortunately the last cm before the cylinder wasn't covered and I had two MOT fails due to slight corrosion on this part of the pipe. I suspect the reason why Kunifer isn't used is primarily cost - a few pounds extra per car adds up when multiplied by the huge number or cars sold. Also, the second or third owner will probably have to replace the pipes - more cash in the tills for the motor industry!

Kunifer has a lower pressure rating than steel, but still easily capable of handling all braking pressures. It's more malleable than steel, so much easier to flare & fit. Back in the eighties, I re-plumbed the brake lines on my Austin Maxi for about £15, and I still have some Kunifer left over in the garage. I also have a flaring kit and some fittings, which I certainly will never use - I'm too old for much car maintenance these days and have lost my old enthusiasm.

Most importantly, plain copper pipe must never be used - it must be Kunifer or equivalent to the relevant BS standard.

Terry D.

Why must plain copper never be fitted? I fitted copper to a mini that I restored and ran about in for two years with not a problem.

Slight corrosion is not an MoT fail. Corrosion that severely impacts the thickness of the pipe is a failure, so if you can dig your nail in and pull against the corrosion it MAY be a fail, depends on the tester, but certainly surface corrosion is not a fail.

Where would you get get plain copper pipe from anyway?

I did wonder. But *all* the pipes needed replacing. The bodywork is in very good condition.

The car has lived on the NE coast of Scotland where they salt the roads - but don't they on most countries in Europe?

What make of car?

The garage where my brother worked at the time.

"gazzafield" wrote in message news: snipped-for-privacy@pipex.net...

Copper work hardens and can and does just snap, happened to me on a 1970 Volvo 122, Some of the pipes had been replaced with copper, well before I got the car, one of the pipes that crossed the rear axle, neatly broke at the brake cylinder, probably because it hadn't been clipped on the whole length and was vibrating. Made for a heartstopping moment when I went to brake!! thank goodness for dual circuit braking systems.

All copper rapidly replaced with kunifer ....

Des

Most auto factors.

example.

FWIW I've never had any problems with plain copper. And neither have my MOT testers.

to be honest trying to determine whether a brake pipe has reached a failure criteria[1] is a pain sometimes, ive passed some in the past only for it to fail in the brake roller, the routing doesn't help as some pipes disappear behind the fuel tank ect, I know if I had a light scrape[2] &I could reach it ,it would possibly fail, but instead a pass & advise is issued.

[1] Chafing, corrosion of, or damage to, a rigid brake pipe so that its wall thickness is reduced by 1/3 (eg approximately 0.25mm for typical hydraulic brake pipe) is a reason for rejection. [2] To assess correctly the condition of corroded metal pipes, surface dirt might have to be removed. This might require light scraping with the Corrosion Assessment Tool 'spade end'. Care must be taken not to damage any protective coating.

The MOT only cost £10 at the time, with a free re-test, so I let them do the job for a few quid more, At their prices, it was worth every penny - I couldn't even undo the connection to the wheel cylinder. It also ensured an MOT pass. The pipe was replaced with Kunifer. The garage didn't even try to sell me new discs or anything other than new wiper blades. Unfortunately, since then, I've been caught out by the new brake disc scam at a fast-fit outfit. Strangely, the old discs had mysteriously disappeared when I collected the car.

Terry D.

"gazzafield" wrote in message news: snipped-for-privacy@pipex.net...

2 main reasons. Copper hardens with age, and is highly susceptible to fatigue cracking if subjected to vibration, which could easily occur on a car unless the pipe is well supported along it's length. Back in the 20's and 30's it was common to use small bore copper pipes to feed the fuel to the carburettor. To cater for the movement of the engine, the pipe would have several coils between the fixed union on the chassis and the carburettor. Part of the service schedule involved removing the pipe completely. Heating it until red hot then quenching in cold water to soften it. This would be done about once a year. It was well known at the time that failing to do so could result in a fire if the pipe cracked and leaked fuel over the engine, exhaust pipe etc.

I fitted copper to a mini that I

Quite possibly, but the risk of a pipe failure is always there with copper, and the problem is you get no visible warning of imminent failure. At least with Bundy you can see it rusting. Mike.

Yes you have to take them off to fit the new ones :-) :-) :-)