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MG MGA - Petrol leak

Does anyone know if there is a torque setting for the banjo connectors on the carburettors, please?
I just found I have petrol leaking from both banjo joints at either end of the carbs. All fittings are new but I obviously didn't tighten them sufficiently when refitting. I am just frightened I might overtighten.
Is it common for them to work loose?
Graham M V

Did you use new sealing washers? The washers deform to seal making them one use parts. Both copper as original and aluminum work. Snug with a wrench is good enough. Hollow banjo bolts are easy to break so be careful.
R J Brown

Hi RJ. Yes it was all new. And yes, breaking them is what I'm worried about! I am sure I did them pretty tight when I fitted it, so that's why I was wondering if there was a torque setting.
Graham M V

This all sounds very strange to me - I've used the same old fibre washers for the last 12 years on mine, no gasket goo, no touble... Should you be looking for something else here?
Pete
Pete Tipping

My banjos seem to leak if I disturb them. Undo them to clean the little "thimble" filters, do them back up and petrol seeps out, usually a slow weap. I find myself having to fit new fibre washers nearly every time. Should they be copper or aluminium, sorry, aluminum, as RJ says?
Lindsay Sampford

The ones that come from Moss are fiber. I put new ones on mine recently and they still weep. I had to put double washers on the rear banjo. The shoulder of the banjo is a bit too high for just one (the bolt bottoms out before compressing just one washer).
JM Morris

I've never seen any but red fiber. I soak them in oil before installing, which seems to help more recently than it used to - they might have changed like everything else, seem harder. Also be sure the threads in the lid are clean; carbs that sat a long time frequently have hard corrosion deposits on the bottom side that will stop the bolt. Oil or Lubriplate on bolt face & threads. The banjo has one side recessed - goes toward the bolt head; flat side toward carb. The line will not tighten correctly if the recess is on the carb side! If the bolt will not tighten with one washer in place and one left out there is something wrong (but don't forget the second washer after checking!).
I've never seen one of these bolts break or strip, and I've had some that took heat + a good smack with a hammer on a long box wrench. It is possible to break the carb to float chamber connection though - had a few sad sacks come in with bits in paw.

FRM
Fletcher R Millmore

Copper, aluminum of fiber all work. JM Morris might be onto something.
R J Brown

Graham - To stop the leak, use a good long spanner, take a deep breath and really reef on the end of the spanner. When it seems like the threads won't take any more torque, bounce of the spanner a time or two. Unless the threads in the float chamber lids are really rotten, they will not strip (even though you think that they might). Turn on the ignition and check for leaks - if any are still present, bounce on the spanner a couple more times. One of the problems with the fiber washers is that they will sometimes allow fuel to seep through the edges. With sufficient tightening, this can be stopped. Cheers - Dave

PS. I've had the same problem on out TD.
David DuBois

Thanks. I have done exactly what David said and it seems to have sorted it, at least for the time being.

It looks like this is a farly common problem. I will keep an eye on it and if necessary try the double washer suggestion. Thanks.
Graham M V

David, I do like you said but I support the float chamber with the other hand so as not to strain the rubber float bowl seals. Does the TD have fibre washers where the float bowl joins the carb body like the early ZA Magnettes did?
Lindsay Sampford

Lindsay - "Does the TD have fibre washers where the float bowl joins the carb body like the early ZA Magnettes did?"

Yes, makes it easier to apply a lot of torque to the banjo fitting.

Graham - "I will keep an eye on it and if necessary try the double washer suggestion.

Double fiber washers will probably make it worse. If you have more problems, try to get a copper or aluminum washer. Cheers - Dave
David DuBois

Do you have the washers on the right side of the banjo fittings - I think it's possible to assemble them the wrong way round.

JIM
AJ Mail

This thread was discussed between 25/06/2010 and 27/06/2010

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