Amazon brake line joiners

[Arthur Capstick]

https://www.amazon.co.uk/dp/B0C2PLXBV2?psc=1&r...

I purchased these joiners but was slightly disconcerted when I discovered they come with olives. The description does state they are suitable for brake lines with double flare ends. I definitely wouldn't rely on olive compression for a brake line so I'm assuming you bin the olives and make off a double flare. Is this an acceptable practice?

Many Thanks

Colin

[E-bmw]

While it may say they are, but I would say they are NOT suitable for brake lines.

If you need to join brake lines, just get male & female fittings and flare accordingly they are cheaper & designed for the task.

https://www.amazon.co.uk/10mm-Short-Brake-FEMALE-M...

Not quite sure why you were disconcerted when you discovered they had olives, they are clearly on show

[stevieturbo]

they might be suitable for brake lines on something, but most certainly not a road going car.

If you need to join two brake pipes together, use this sort of thing.

https://www.amazon.co.uk/ASC-FEMALE-BRAKE-PIPE-CON...

AFAIK you are not allowed to directly join two brake pipes together in a male/female arrangement. It might be ok for steel on steel, but absolutely not with any soft metals like copper

Edited by stevieturbo on Saturday 16th September 21:17

[GreenV8S]

I'd want to see what was happening on the inside where the flare would be sealing. Those olives don't appear to have a 45 degree clamping face so I doubt the nut and housing sealing face geometry is right for a standard flare. I suspect these are designed as compression fittings and the seller has worked out that it's possible to get a flared end to fit inside and sort of seal.

I would pay no attention to the 'suitable for ...' wording in the add.

[stevieturbo]

The most dangerous thing about them...is externally they appear like normal jointers

So even an experienced eye might look at them installed, and think they are normal.

Absolutely do not use them on the brakes of any road going vehicle.

[TwinKam]

Frightening!

[TwinKam]

stevieturbo said:

AFAIK you are not allowed to directly join two brake pipes together in a male/female arrangement. It might be ok for steel on steel, but absolutely not with any soft metals like copper

Edited by stevieturbo on Saturday 16th September 21:17

Some cars do come from the factory with that arrangement, Stevie (eg Fiestas, by the fuel tank), but yes the pipes are all steel.

[stevieturbo]

TwinKam said:

Some cars do come from the factory with that arrangement, Stevie (eg Fiestas, by the fuel tank), but yes the pipes are all steel.

I think it's soft/soft is the big no no.

And certainly compression fittings would be an equally big no no.

Not saying compression would not hold the pressure, there's a good chance it probable would. But it is not how any car braking system has been done that I've ever seen.

[GreenV8S]

stevieturbo said:

Not saying compression would not hold the pressure, there's a good chance it probable would.

The compression fittings I've seen have pressure ratings in the low hundreds of PSI. A car brake system could reach a couple of thousand. It might hold the pressure, but I expect you'd be way outside its spec.

[stevieturbo]

GreenV8S said:

The compression fittings I've seen have pressure ratings in the low hundreds of PSI. A car brake system could reach a couple of thousand. It might hold the pressure, but I expect you'd be way outside its spec.

I've only datalogged braking pressure on one car, and it was in the 50 bar range under heavy braking, that's around 7-800psi. I'm sure much higher would have resulted in locked brakes as it was already pulling over 1G at that point

This would suggest some can do in the thousands. Still 100% not recommended for vehicle braking systems though, but interesting to see

https://www.beswick.com/resources/the-basics-of-co...


https://4lifetimelines.com/products/high-pressure-...