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BROTHER LOVE · 14-04-2011, 07:34

Can anyone offer some advice on fixing a leaky banjo bolt. For some reason I, and 2 mechanics have not been able to stop this drip. It is dripping at where the banjo bolt enters the fuel pump, and connects 2 the #1 cyl. pipe. Is there supposed 2b one washer on each side, 2 on 1, 1 on the other. Does the alignment of the hole/holes on the banjo bolt, and the washers have anything to do with it.

This is on a Perkins 1981, 4108

**Wotname** · 14-04-2011, 07:37

Try NEW washers, one on each side.

Lancerbye · 14-04-2011, 07:42

Welcome aboard. Ditto on what Wotname said. Should be copper washers.

Ironhorse74 · 14-04-2011, 07:51

Exactly what Wotname and Lancerbye said. If however that does not stop it. Harley uses the same fittings on their bike brakes. The washers Harley uses have an O-ring built into the inside of the washer. Brakes are higher pressure than fuel fittings. I believe 3/8 and 5/16 ID are available.

**Wotname** · 14-04-2011, 08:02

If the existing washers are copper and are NOT crush washers, then you can try heating them up with a torch (say MAPP gas), letting them cool and refitting. Copper washers do work harden with repeated use and the heat will anneal them beautifully; however if they are crush washers then they should be replaced with new crush washers IMO.

BROTHER LOVE · 14-04-2011, 09:50

Thanks for the response!. They r the alumunum ones. Although the mech. @ Green Turtle n Bahama's replaced the orig. w copper ones, with the same result. He did not heat them. According to the diagram in the manual, it looks like one washer on each side. But when this is done it leaks worse then the current set up of 2 washers on the out side of banjo fitting, and 1 on the inside. When tightend up with this conf. the leak stops, but then the washers slowly crush under the preasure, and here we go again. Maybe I could place a copper one between the two outside to stop the crushing. Does it matter how the bolt lines up in the fuel pump in relation to the washers. My thought is that the holes in the bolt are lined up between the washers and therefore not sealing prop. I have replaced the banjo bolt, and banjo fitting, but have not replaced the pipe. That will b next. Thank u again for the response. BL

Chief Engineer · 14-04-2011, 13:53

one washer each side....don't overtighten......you may have stripped the threads and the fuel is leaking past the buggered threads

Blue Stocking · 14-04-2011, 14:46

Quote:

Originally Posted by Wotname

If the existing washers are copper and are NOT crush washers, then you can try heating them up with a torch (say MAPP gas), letting them cool and refitting. Copper washers do work harden with repeated use and the heat will anneal them beautifully; however if they are crush washers then they should be replaced with new crush washers IMO.

AAMOI, don't you anneal copper by rapidly quenching in cold water?

Go with the new washers.

sigmasailor · 14-04-2011, 15:05

Soften the washers by making them red hot and cooling them down quickly by dumping in water; you will be amazed at how soft they will get

s/v 'Faith' · 14-04-2011, 15:10

Quote:

Originally Posted by Chief Engineer

one washer each side....don't overtighten......you may have stripped the threads and the fuel is leaking past the buggered threads

Yup,

Also seen the bolt heads get tweaked as the bolt gets overtorqued.

After that, they will not seal.... look closely at the nice round holes drilled through the bolt..... if they look oval it is time to replace it.

Play Actor · 14-04-2011, 15:17

I know it's unorthodox, but I've gotten by in emergencies by cutting gaskets from heavy fiber gasket material and coating them lightly with #2 Permatex to replace crush washers. One joint repaired this way lasted the life of the fuel lift pump.

If you've replaced the crush washers, the mating surface on the banjo fitting or the pump or the bolt may be damaged. Clean them up and inspect carefully with good light and a magnifying glass.

Artif · 14-04-2011, 15:20

Quote:

Originally Posted by BROTHER LOVE

According to the diagram in the manual, it looks like one washer on each side. But when this is done it leaks worse then the current set up of 2 washers on the out side of banjo fitting, and 1 on the inside. When tightend up with this conf. the leak stops, but then the washers slowly crush under the preasure, and here we go again. BL

Sounds like the bolt has been over torqued and stretched, causing it to bottom out before clamping the sealing washers properly. A common problem as many people don't realise how little torque is required.
You should only need one washer each side for a good seal, aluminium or copper doesn't really matter, they both work well.