View Full Version : Fuel line problems.

02-06-2005, 11:49 AM
I'm very frustrated with my TR6. It's had a bad fuel smell since day one, and it does not want to be fixed. I'm going on four months down trying to solve it, with another nice weekend spent working on junk instead of driving. After repairing all the carb bowl leaks, I waited three weeks for a fuel pump kit. The kit was fine, but the pump to block gasket fell apart as soon as it was touched. I ended up making one out of better material, now I'm trying to figure out the lines. There are compression sleeves on both lines going into the pump, both were destroyed. I found replacements, but they leak like crazy. I've never seen compression sleeves on an automotive fuel system before, but I see in the parts books it's correct. I'm getting tired of paying minimum shipping charges for $.45 parts I have to wait weeks for, it seems the ones I source local are incorrect. If I can't get this car to stop smelling up my house it's going to have to go.

02-06-2005, 01:18 PM
Dont forget to check the complicated vapor system that this girl has....there are lots of lines and hoses that can and do leak vapor before it can reach the charcoal canister(which is probably shot). There is also a hose comming off the tank that is famous for causing trouble.....
MD(mad dog)

Geo Hahn
02-06-2005, 01:57 PM
To that I'll add the gasket around the tank sending unit can also be a source of fumes with no other evidence of leaking.

I am not familiar with the TR6 but the compression fittings on the TR3 & 4 are not your local hardware store variety. Here's a recent post from another list that may or may not apply:

...I was actually lucky enough to find a nut that met all the requirements at my local auto parts house. My description was greek to them, but they let me look in their parts bin and Lo! there was one. It's a special nut designed to put 1/4" od tubing into a 5/16" fitting, and apparently this was once a common application for it as the bin said "Fuel pump fittings".

However, that still didn't solve the problem ! Apparently, the original fitting used a special compression sleeve that was taller than the sleeves available today. I solved my problem by making a special nut on the lathe, with a blank area below the threads. Others have "cut & pasted" two ferrules (compression sleeves) together to make one taller one. Or, you could just use 5/16" tubing and convert to 1/4" somewhere between the pump & the carbs. With care, you could probably even bore out a short length of 5/16" steel tubing to push over the 1/4" right at the pump.

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02-06-2005, 02:50 PM
The compression fittings on the fuel pump are poor by design. To make things worse they don't comply to normal compression fitting standards. It seems the compression nut is longer than normal which means the replacement doesn't compress the ferrul completly and the leak continues. Finding the longer nut for the proper fuel line diameter proved futile. I eventualy used a new standard nut & doubled up the ferruls & got lucky. Now I know why electric fuel pumps would be a good upgrade.
As far as the constant fuel smell, determan if it's comming from the front or rear of the car. The rear fuel tank area has many seals and hoses that deteriorate over time & are definitly problem areas. The short hose between the filler cap & tank often the clamps loosen & emit an odor while driving. Also check the charcoal canister. They can be replenished with fish tank charcoal easily.
One last thing to check-The mechanical fuel pumps have a history of leaking into the sump when going bad. Make sure this is not the case. This might become evident in the oil pressure readings or pull the dip stick out & look for signs of fuel & smell of gas.

02-06-2005, 03:25 PM
Fuel was peeing out of the pump, first washing out the oil, then bad enough to drip on the floor. I found it was the pump simply by pinching the fuel hoses before and after the pump, lines pinched, smell gone. Lines unpinched, smell returns. I rebuilt the pump, which it needed as the diaphragm was ugly. After reinstalling it, as soon as I unpinched the lines and primed it, the lines started leaking badly. Moss sells compression sleeves for both lines, but I'm tiring of paying $15 shipping charges on $.95 parts just to have them not work. About 75% of what I get from all of the big 3 ends up in the trash. Has anyone used Moss compression sleeves?

02-06-2005, 05:37 PM
35th, I have used standard compression sleeves on my fuel pump (73 TR6) and have never had a problem. Well, never say never. I did untill I realized what the plumber told me long ago, "When you think you tightened the compression sleave enough, you overtightened it." Too, many times the pipes to the pump have themselves been squished and won't allow for a good seal. Gasoline (sorry, petrol) will go where water won't. NEVER reuse a compression sleave, even once.


02-06-2005, 05:43 PM
Moss has deeper inventory but hammers you on shipping. I've spoken to them about that but they stick by their shiiping & handling policy. TRF ships with standard UPS rates, no adders but inventory levels fluctuate & they don't get you the goods as fast.
When ever possible I try to work in more conventional replacements, I worry about reliability & performance more than originality. There is a place for everyone but I find most performance enthousiasts tend to drive the car more & pose next to it less.
This a whole new world compared to the German engineering you've been wrenching on /ubbthreads/images/graemlins/wink.gif . As quirky as they are, these cars have great race history & enormous potential to be competitive against todays more tech advanced cars, it just takes more than a chip & a laptop.
That BMW six is looking better & better.

02-06-2005, 06:04 PM
might try the little british car company. Online only, but they seem more reasonable on shipping & handling, especially if its just a small item that they can mail out.

02-06-2005, 06:47 PM
So, is my car correct having a smaller OD fuel line coming out of the pump, or is Moss correct that they are the same?

Geo Hahn
02-06-2005, 07:07 PM
Can't answer that... though on the TR2/3/4 the inlet line is 5/16 and the outlet is 1/4.

Don't see how you can avoid reusing the compression sleeve... mine is married for life to the outlet line.

I am fortunate enough to have a local Moss distributor just a couple of miles down the road so I do not incur shipping. Better still he is real good about having the common (and much uncommon) stuff right on the shelf.

Your local club members should know if there is a Moss resaler in your area. If you can find one nearby you will have better access to TR parts than we had when there were still Triumph dealers around.

02-07-2005, 04:30 PM
I went down to the local specialist, he replaces the compression sleeve fittings with barbs like the later cars. Since I don't care to duplicate a poor design, that's the way I'll be going.

02-10-2005, 12:02 AM
I bought two fuel line barbs for $4.00 at the fittings and hose shop. Hooked everything up, primed it, and it's been fueled up for two hours with no smell. New record!