Brake fluid weep

[robbo911]

I have an S type which appears to have had the brake master cylinder replaced (don't have full service history) with a Girling one. It has a banjo connector at one end which looks like the pictures I can see of the SNG Barrett Girling replacement part for the original Dunlop one. The master cylinder may have been replaced at the same time as having Coopercraft calipers fitted to the front. There is a small leak from the pipe from the reservoir to the master cylinder coming from the back of the union which attaches to the master cylinder. Tightening it has not improved the situation. So I am wondering whether the replacement cylinder should have had a different pipe from the reservoir (maybe metric vs imperial?) fitted and maybe that was not done, or similar. Any help from anyone who has experience of this would be gratefully received.
thanks in advance.

[B87UL]

Robbo

If I understand correctly you have a leak from between the banjo face and the master cylinder body facing. On this type of cylinder / banjo fitting you will find the banjo has not been fettled back far enough to allow the banjo bolt / pipe fitting to cramp the cylinder face copper washer.
In this instance the fix is to fit two copper washers between the cylinder face and banjo end fitting, this lifts the end fitting far enough clear of the cylinder to allow the copper washers to cramp correctly. Do not try to tighten the banjo bolt in an attempt to cure the leak, it will not do so and will lead to distortion on the faces.

[robbo911]

Thanks for your reply. I don't think I was clear in my initial post - the leak is not coming from between the banjo and the face of the master cylinder, it is coming from the back of the union between the pipe from the reservoir and the banjo fitting. It is that pipe union/nut that I have tried without success to tighten to stop the leak.

[B87UL]

Robbo
Any chance of a photograph here to show the problem more clearly?

[piman]

Hello Robbo,

I think you'll need to dismantle it and check the condition of the flare, could it be cracked? (I'm assuming it is flared?).

Alec

[robbo911]

Thanks both. I am away for a few days so won't get a chance either to photograph or dismantle it till I am back. I'll take a look at the weekend, it is probably easier to take it apart and take a look.

[robbo911]

Had a look at the weekend. No leak apparent so thought I'd take it for a run to see if that caused the leak to reappear. Wanted to check condition of plugs/points first - whilst doing that it transpired that the PO had cross threaded one of the plugs. So I need to sort that out before I investigate the brakes further...

Thanks for all the help so far: when I get back to looking at the brakes I may be back for more advice!