Dual circuit brakes.

Dunno. Did they actually become mandatory, or are they one of those things that became so obviously the way to go that no manufacturer would fail to fit them?

Steve

"shazzbat" gurgled happily, sounding much like they were saying:

I don't think they ever did. B'sides, do modern ABS/EBA cars even have "dual circuit" brakes?

There's a requirement that the brakes can achieve a certain efficiency after one circuit fails, so unless you've got some other extreme cunningness it's mandatory. Plus you need a 25% efficient handbrake for single circuit systems. I can't recall seeing anything made since the mid

"Duncan Wood" gurgled happily, sounding much like they were saying:

Depends what you mean by "single-circuit".

Right up until the end of production in 1990, 2cvs had one pipe from master cylinder to the front brakes, and one pipe from master cylinder to the rear brakes. In the mid '70s, the master changed from one with a single piston to one with a pair of pistons, and a reservoir split so that if one half empties the other retains some fluid. Would you call that "dual-circuit"? It's certainly not the usual diagonal split.

That's dual circuit, diagonal split's done to achieve enough efficiency on cars with relatively light rear ends, Front rear splits still fairly common on RWD cars. Metros had dual front circuits .

"Duncan Wood" gurgled happily, sounding much like they were saying:

I did say "2cv"...

The only difference in braking system is the master cylinder and reservoir. Rear brakes on a 2cv mainly contribute a little bit of sound effect and sod all else.

As others said no idea. My 1979 SAAB 900 had dual circuit ... it was put to the test and passed (well one pipe failed) but it worked as intended.

Charles

I don't know about the UK, but as a point of reference I remember them becoming mandatory here in Australia in 1968.

I worked in the motor trade in Brisbane at the time.

John

I think saab in the 60's was the first with (diagonally split) dual circuit brakes...

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:

From personal recollection... Moggy Minor vans were still single circuit right up until the end (1971). Marina vans were dual from inception and so was nearly everything else at the time. I unrecall whether it was mandatory at that stage or later.

I think Minis & MGBs switched in 1976, but I could be wrong.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Duncan Wood" saying something like:

Yeah, I think it wasn't mandatory until about then (or later). Actually, I could be wrong about the early Marina vans; they might have been single-circuit, penny-pinching being the order of the day at BL.