Hitchcocks Forum

Anybody know if these washers are suitable for front brake line to caliper joint , having trouble sealing banjo union with copper washers.

We used to use them on impulse pressure rigs for destruction testing of hydraulic hose.

They were subjected to pressures were far greater than you could ever hope to achieve with a brake master cylinder.

Frank

Personally I would check the mating surfaces closely, there should be no leaks.

If a banjo type union will not seal with new copper washers, then its usually been overtighten previously and the banjo has been crushed and the surfaces may not be flat anymore, as Papasmurf says " check the mating surface closely".

Are you using the original copper washers? If so they will need annealing.
We used dowty washers on FAR greater pressures as well - no problem.

From a brief spot of Googling, only Dowty seals with a nitrile rubber seal are suitable. Apparently, some are made with natural rubber which is NOT suitable for brake lines. I would recommend that anyone considering this should research thoroughly rather than relying on 'opinions' (including mine!) on forums.


I always use new copper washers on brake lines. I have never had a problem with sealing.

It also occurs to me that I have never heard of car or motorcycle manufacturers using Dowty seals on brake lines.

Have to concur with another Allan entirely. In 50+ years in the retail motor/motorcycle trades, I've never heard of anyone using Dowty washers on hydaulic brake lines either.... there has to be a reason, I think. Standard practice always used to be (and I suspect still is) to replace any removed copper washers with new COPPER washers. I have a strong feeling that if new copper washers fail to cure your leak, Scotty, you have a problem elsewhere.