T-Series Carb banjo washer leaks?

I removed the MG's SU carb banjos to check and clean the fuel filters inside each carb bowl head. Filters were clean, so no worries.

Replaced the banjos and fiber washers, tightened banjo bolts - but fuel leaked around the washers (both sides of bolt) soon as pump came on.

Replaced the washers with new washers from Abingdon Spares - no change. Leaks continue. Fuel actually drips from the front banjo when the pump is on. Fuel isn't leaking from the fuel line fittings - just from around the banjo bolt washers, both washers of each banjo.

Replaced fuel lines with new lines (pump to rear carb, rear carb to front carb), new banjos, new bolts and new washers (again).

Both banjos still leak at both washers. Banjo bolts are *tight*.

Has anyone ever experienced this? Those banjo fittings shouldn't need a sealant. Any suggestions? Do the leaks stop after a few days? Should I have prepared the washers in some way (coat with grease, oil, kerosene, etc.)?

I even tried putting the original old washers back - no improvement.

Of course, there were no leaks at all until I decided to check/clean those filters. Story of my life ...

Thanks.
Tom M.

Perhaps you have some crud in the bolt threads that prevents the drawing down of the banjo when tightened. The bolts should tighten the banjo enough so that it can't move. The correct fiber washer is necessary , its a bit thicker and has a small outside diameter. I would also check the sealing face of the float bowl top and true it up with a flat file in a criss cross pattern , over the years that can get distorted somewhat. The bolt threads just need a bit of grease but no sealants or teflon tape.

Thanks. These are brand new banjos and banjo bolts (and new washers).

What thickness and durometer should those washers be?

Tom M.

Are these copper washers and if so do they need to be annealed?

It would be the inside threads of the float bowl top you need to be concerned with . Tighten the bolts into the cap without the banjos and see if you have enough travel to clamp the banjo properly.

When I read this, my first thought also was that you're not really tightening the bolt against the washers, for whatever reason.

A lot of the new parts are not well made or not made exactly right. All it takes is for the washer thickness or the thickness of the banjo fitting to be wrong. I would check these with a micrometer and compare to the originals.

If the banjo tight enough so that you can't move it? If it moves, the problem is obvious.

Beyond that, if the surfaces are smooth and flat and you can tighten it enough to get good compression of the washer, it will seal. This ain't the proverbial rocket science. If this all checks out, look for a crack somewhere near the fitting--the fitting itself might not be leaking but because of a nearby crack, it may look like it is.

I just heard back from Joe Curto.


"accorrding to my gasket supplier there used to be different hardness of the red fibre, now they only make 1 which is the hardest of the former ones, The ones I have work mostly ... I do have soft aluminum ones "


So it may be that Joe Curto's gaskets are from the older stock, slightly softer than the ones available today.


As I posted at the top, I now have new banjos, new banjo bolts, new washers, and new fuel lines. The bolts are *tight*, and the banjos don't move. No leaks anywhere but at the washers.


So I made my own washers out of buna-n material - and the problem is solved. No leaks since I put them on a few days ago.


Tom M.

The rear carb banjo fittings on my 57 TR3 are also leaking. I have replaced the fiber washers with new ones. Still leaking. I have been afraid to use too much force to tighten the banjos. I am afraid I could strip the float. appears my options are to use some kind of sealant, use a different type of washer or make my own.

I would appreciate advice from the group

Would fit alloy ones as they are softer.

Grantura_MKI said:

Would fit alloy ones as they are softer.

Click to expand...

And a (VERY!) thin film of Hylomar wouldn't hurt.