brakes banjos weeping

[bloodknock]

Hi folks
i'm on the braking sytem of my sprint. Ive sorted the master cylinders and am bleeding the system. Every banjo and coupling has been either cleaned or replaced as necessary, ive had some leaks, cured by pinching up the connections, however, i can still see miniscule weeps in some of these joints particularly the banjos.
i mean these are just trace amounts of fluid, now is this something to be concerned about? im reluctant to tighten them further.
regards
Bob

[661]

Are the thin copper rings new?
Cheap to replace.

[lotusfan]

Bob

You want zero leaks from the joints, as Graeme suggests replace the copper washers and anneal them before use.

[alan.barker]

+1 anneal copper washers before fitting
Alan

[bloodknock]

Morning Chaps
On my Banjos are two distinct sizes of washer, the larger internal diameter fits snugly under the head, the smaller on the caliper face. Ive been unable to locate the same washers, only those with the larger diameter which makes them a piss fit at the caliper face. can someone point me to a correct reliable source please?
Some say quench, some say allow to cool slowly in the air. Whats the opinion on process?
Bob

[alan.barker]

Always quench to anneal copper.
Alan

[bloodknock]

Thanks Alan
My existing washers are 0.43" ID = Banjo bolt head, 0.38" ID = Caliper face. Thats .05" difference. My Banjo bolts have a shoulder at the bolt head.
Bob

[Craven]

Are you using Silicon Brake Fluid? I found this quite a problem to seal, ended up using Dowty Seals.
To anneal copper heat cherry red and cool slowly. An old trick is to tap gently on head of banjo bolt and retighten.

[alan.barker]

Maybe my memory is starting to play up.
During my apprenticeship i remember heating Copper then quench to soften/ anneal.
For Steel it was the opposite heat then quench would harden.
Alan

[terryp]

Also make sure you have 3/8" copper washers rather than the slightly larger 10mm copper washers.
The imperial ones give slightly more in the way of a seal.
Terry

[rcraven]

On a different car (i.e. not Lotus) with quite large banjos in the oil supply system I've found that banjos can leak if some time in the past they've been tightened too much and got slightly squashed. If the surface got even slightly depressed rather than perfectly flat they might leak, though they were admittedly large brass banjos and therefore susceptible to squashing if severely overtightened.
If this has happened the solution might be to get new banjos for any you have not already replaced. Or at least try testing with a perfectly straight edge across the surface.

[bloodknock]

Wiki - How to anneal copper goes with cold water quench.

[bloodknock]

Thanks Terry
I'm using DOT4 Fluid.
My worry is that existing washers are 0.43" ID = Banjo bolt head, 0.38" ID = Caliper face. Thats .05" difference. My Banjo bolts have a shoulder at the bolt head.
I dont know if this is critical to a seal, but in any case I dont know where I can get the correct ID washers
Regads
Bob

[terryp]

Thanks Terry
I'm using DOT4 Fluid.
My worry is that existing washers are 0.43" ID = Banjo bolt head, 0.38" ID = Caliper face. Thats .05" difference. My Banjo bolts have a shoulder at the bolt head.
I dont know if this is critical to a seal, but in any case I dont know where I can get the correct ID washers
Regads
Bob

Bob
I just bought mine from EBay, search for imperial copper washers, I wasn?t happy with the washers that came with the my new banjos and i suspect the ones I got were 10mm
All the best
Terry

[rcraven]

As to whether annealing copper requires it to be quenched after heating, opinions differ, and acording to a metallurgist writing on another motoring forum quenching is not essential and
"The main reason for suggesting water quenching is to minimise the amount of oxidation during cooling".