Sealing the joints ( brakes ) ?

[Arfron]

Can anyone help me with a brake problem . A banjo on the rear brake cylinder was split . I replaced the banjo assembly , and new washers. However, the joints still appear to allow fluid to seep between the banjo and the large and small washer . Is there a jointing product which I can safely use to seal the joints ? (As in nomal gasket sealing products ? ) I have taken up the slack , but I don't want to strip the threds . ( E.g.Gasket jointing products from Halfords , blue stuff ??? ) Arfron

[lowedb]

Are you using the right washers? They should be soft copper, so they deform like normal gaskets when you tighten up. This is why you should never re-use them.

Personally, I would never use sealing compound on braking systems.

[Arfron]

Thanks for the reply . I bought the washers from Bull motif ( and the parts ) so assume the are the correct seals ? Arfron

[lowedb]

I would expect they are OK, then.

I'm sure you've checked to make sure no bit's of grit got on the faces or in the washers already.

It's worth looking at the new banjo, too I guess. Check the sealing faces to make sure it didn't get a scratch on it when they were storing it or packing it. A scratch that runs from the inside to outside edge will not be filled by a soft washer, they can't deform that much. Just because it's new doesn't guarantee its not faulty.

[Benjy]

I had a similar problem, mostly due to grit in the threads. Also, I seem to remember that they only fit properly one way round, but could be wrong.

Ben

[Arfron]

Thanks for the thoughts on the banjo problems . I had a chat with the mechanic in work , and he is going to try and get me some ' dumpy ' ? washers . They are copper washers with a seal sandwiched between them, he says they will seal anything !! We use them on the hydraulics on the lorry grabs Apparently the washers are available in all sizes . I'll let you know how this progresses .
Regards Arfron

[rayofleamington]

the hydraulics washers work fine upto aroud 80 bar , but are not always ideal at at brake system pressure.

it should seal on the washer not the threads, so have a look for any fine scratches on the bajo, the steel face or the washers.

to re-use the washers, you can soften them by heating them to red hot (eg. on a gas ring - with a pair of thin nosed pliers to hold them in the flame) then drop them immediately in water.
(They can get work hardened if you tighten them up a few times)

[Arfron]

Thanks for the message Rayof etc. What bar is the operational pressure of brakes ? I thought it was lower than 80 bar ?? Anyway, I take your point Arfron