MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - stripped out plastic thread in fuel pump outlet

Hiya folks!

I've stripped out the plastic thread in my fuel pump outlet. The amount of banjo bolt thread protruding through the banjo was only about a half of the length of the plastic thread in the outlet, which I presume has caused it to strip out. It wouldn't stop leaking, even with new fibre washers, so I kept tightening...

Is there any way I can fix this? It's a brand new pump so I am reluctant to just throw it away. Could I araldite the banjo bolt in? Or maybe use a longer bolt and hope it picks up and the remaining threads? No idea of what size, or pitch it is.

Any suggestions greatly appreciated!

Cheers, Rich
r j symons

Rich - If that is an ECCO pump, it states clearly, Not to use the standard banjo fitting - use only the fitting that is supplied with the pump. I don't know of any way to repair the plastic threads in the pump - if the araldite works, you can perhaps adapt the supplied fittings to make thing work, but using the banjo fittings is almost always going to fail. Cheers - Dave
DW DuBois

I would be tempted to junk it and take it as a lesson learned. One of those came to me on a V8 and although it didn't leak it started short-stroking and causing fuel starvation, and I was stranded until it decided to start working normally again. One time it did it at home when I had time to investigate, and even though it is a rubber bumper so the electrics end was in the boot and could be accessed easily nothing I did made any difference.

Get a pukka SU, and I wouldn't have an electronic version of those either.
Paul Hunt

Paul,
"Get a pukka SU, and I wouldn't have an electronic version of those either."

The all electronic pumps are now coming out of the box, working properly. For a number of years they would not work out of the box or would fail shortly after installation. It appears that someone at BFS has finally learned how to set the adjustment of the Hall shield properly (getting it into the middle of the range where the pump runs correctly instead of right on the edge of the range). Once working, they are every bit as good as the original points style - I have had on in our MGB (that I readjust before installing it) for well over ten years and it has never missed a beat. Cheers - Dave

PS - I wouldn't get one of the plastic pumps either (although I purchased on just to see if the quality was better than previously - it is, but...)

DW DuBois

Thanks guys for your comments. I have removed all banjo fittings and have araldited (epoxy resin) the plastic threaded nozzles supplied into the pump body and have also attempted to epoxy one of the two nozzles which snapped in half. Will let you know if all is well when piping up this week
r j symons

I agree (unusual) with Paul, I would bin the pump as it will surely let you down on a dark, wet and stormy night. (Halloween!!)
BUT like Dave I have had an electronic SU on my roadster in excess of 10 years without concern and would have no problem fitting one again.
Allan Reeling

Or you could have tried this idea.

http://www.mgb-stuff.org.uk/saga31.htm

Herb
H J Adler

Herb - I always cringe when I see tapered threads going into the fuel pump ports. Those are BSPP threads and if the tapered threads are tightened too enthusiastically, it can crack the casting (obviously you did not over tighten the fittings). Cheers - Dave
DW DuBois

Hi Dave,

I am fully aware of the danger with tapered threads, which is why I used a reducing bush as well as the elbow, not just the elbow.

Herb
H J Adler

Hi guys. Decided to bin the nasty plastic fittings (which I had glued in - and which came out cleanly) and pop down to my local plumbing suppliers and pick up a couple of brass 3/8 bsp to 6mm hose tails, which have gone in nicely and pulled right up with no cracking. So far. May need to change to 8mm if fuel flow is too low
r j symons

Wonder how long it will last!


r j symons

"May need to change to 8mm if fuel flow is too low"

6mm is 'just less than 1/4' and that is the diameter of the pipe and fitting from the end of the body pipe to the carbs. The minimum recommended delivery at a carb pipe is 1 Imperial pint per minute, and in practice with a standard set-up you should get at least double that. Whilst the diameter is typically 5/16" or 8mm from the tank to the bulkhead I doubt a very short bit of 6mm is going to make a noticeable difference.
Paul Hunt

Thanks, Paul. It's not the rubber 6mm bore pipe which is the prob - it's the internal bore of the 3/8bsp to 6mm barb. It's only about 3mm, which is far, far smaller than the bore of the rigid piping. Hence I may need to go for an 8mm barb to ensure I get say, 5 or 6mm, bore
r j symons

The 1/4" (OD) ports on the carbs etc. are thinner walled than that, but I wouldn't expect much more than 4mm ID. I'd still do a delivery check before digging in again.
Paul Hunt

Ok, thanks Paul. Will give it a go and pipe it all up as it is - as soon as the bloody sun comes back out! Cheers, Rich
r j symons

So, all fixed and working, and no leaks. Decided to go for hose tails with 8mm outlets in the end
r j symons

This thread was discussed between 31/10/2015 and 11/11/2015

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.