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 TD TF 1500 - Runs fine, but dripping fuel

I got my '52 TD last year and upon renewing most of the braking system (pipes, pads, etc...) it ran perfectly.

It has continued to run great this season, but has developed an issue. Upon parking the car, over the next few hours (day?) it drips gas from the carbs, onto or down the throttle linkage, down to the frame, and ultimately onto the floor. It runs great, but the dripping fuel, and the associated smell, is a little much. Any ideas? I replaced the fuel lines last fall, so I doubt it's them.
Stan Griffis

Stan,

Is the gas running down the choke linkage? It sounds like your jet seals are worn out. Moss sells them here: http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=32749#29 Note: they are prone to wear out easily.

If you check the archive, there have been references to a synthetic o-ring that others are using. I wouldn't recommend driving the car until you fix this. Fuel can easily drip onto the hot exhaust and cause a fire.

Good luck, Evan
Evan Ford - TD 27621

Not only are the linkages wet, so are the jet return springs, and about the lower 1/8 of the carb itself.
Stan Griffis

Stan
Sounds like the jet assembly needs seeing to. Maybe one or both of the cork glands on the jets have dried out and cracked. Same with the cork sealing ring. It might be worth renewing these three items first (after soaking replacements in engine oil for a couple of days). I had a problem with a stiff choke which turned out to be dried out cork glands caused through lack of use.
John
54 TF 5924
John James

I'm new to carb repair, how complicated are any of these repairs?

Stan Griffis

Stan,
S.U. carbs are the most UNCOMPLICATED carb in the world. If you contact Midel Pty. Ltd Lakemba N.S.W (Austalia) web site: www.sumidel.com you can buy via air mail complete rebuild kits for two carbs at 75% of what Moss charges and the parts are twice the quality. And you will get them in less than 14 days as I just did and got my carbs working beautifull just today as my car had done a lot of sitting over the last 7yrs before I bought it in Mar 2004.
Greg & Grimm
G.J. Cenzer


I think the answer to dripping carbs on T Types is to stick a pair of MGB 11/2" carbs on. they have sealed jets that very rarely leak and you don't have to mess about with those fiddly damned jet washers as fitted to the H4s!!.
Harry
H.E.W. Walker

Stan,

In my experience, some bolts on the SUs need to be tightened at least once after the carbs have been rebuilt, or just taken off and re-installed.

Other than the jets, I find the two biggest culprits are the fuel line banjo bolt on the float bowl cover, and the bolt securing the float bowl to the throttle body.

Also, check to see that all banjos and bolts have the appropriate washers of appropriate materials (e,g, metal or fiber) in the appropriate order.

Greg
Greg Van Hook

Cork seals should be soaked in oil for a few weeks before installing??



Am contemplating a SU rebuild job for this winter too. Ppl have mentioned there's a good Haynes manual and also a video available - got neither but am on the lookout.



ps: all MGs should carry a fire extinguisher. And don't park near smokers.
Will

First, make sure that the float valves aren't sticking-simple matter to take off tops of bowls and check valves which slide and are easily gummed-up and also check float heights. Second, if the jet seals are leaking, your mixture is always going to be too rich-you probably hardly need to use the choke, I'll bet! If this is the case, your oil will constantly be thinned by the rich mixture-verry verry bad! As said above, this is almost always caused by worn or stiff jet seals. They are fairly easy to change, but I recommend that you don't use the seals that come from Moss. The last ones that I tried, were short peices of rubber tubing. In my experiance, they simply don't work. Get genuine SU seals- and in fact use only SU parts throughout your carbs. They can be gotten from Joe Curto in Flushing NY. I don't have his number handy, but he advertises in the Sacred Octagon. He also has just about any used part that you might need!
Steve Tobias

Stan
Dropping the jets and fitting new seals is relatively simple. Recentreing needle after you have replaced the jet needs a little patience. I'm a rooky and I did mine without any problems, referring to the invaluable instructions in the New England MG T Register T Type Restoration Handbook.
John James

One of the problems encountered in various part of the country is the coming of the so called re-formulated, "summer gas". I have a TF that has never had a carb. rebuild or the seals replaced, and never had any leaks. I religiously use Mobil gas, but out of neccessity I had to fill up with Speedway, which caused immediate leak problems in the carbs and fuel pump. After consulting with a fuel systems eng. at FMC, I found that the controls on the summer additives are not all that accurate in some brands, and that high concentration additive will dissolve and swell most old style seals and gaskets.
This is a common problem in MI. with old cars.
Bowl seals on SU's are one of the big culprits and it is best to replace the fiber seals with O-rings. Check your fuel pump, on mine the gaskets were just mush.

colin stafford

Stan - To get jet seals that won't leak and don't cause the jets to hang up when pulling on the choke, try the teflon 'O' rings offered by Tom Bryant of West Bath, Main, e-mail tbryant@clinic.net. I have has a set in the carbs on our TD for close to 20 years and have never had a leak and they have never caused any sticking. Good luck - Dave
David DuBois

David,

I tried emailing Tom Bryant after you recommended the teflon o-rings to me a few months ago. My email came back undelivered. Any other clues?

Thanks, Greg
Greg Van Hook

Is there any chance that the octane of the fuel I use might have an influence on the seals going?

I ask because I'd put about 50 miles on the car this spring (no leaks) and stopped off this past weekend to buy gas. I put 93 octane in because my day-to-day car uses it, and I didn't even think when I operated the pump, I just put it in. I'm wondering now if that could have had any impact because it was the next morning when I saw the 1st puddle.

Does higher octane fuel eat old rubber?

Stan Griffis

Greg and Stan Tom Bryant's phone number is 207-443-6338. Stan - the octane should not cause the seal to start leaking. Cheers - Dave
David DuBois

Dave - Can I assume the teflon rings are a substitute for the jet seal? Give the name difference (seal vs ring) I just want to make sure this isn't in addition to the seal, but is a suitable substitute.

What other renewables should I also be swapping out in this area since I'll be in there anyway. These cork seals?

Thanks.
Stan Griffis

Stan - The cork seal on under the collar for the large nut under the carburetor that holds the jet assembly together can be replaced with a plain nitril 'O' ring. The one recommended is a Parker P/N 2-117 (ID 0.804", Width 0.104"). I have had som problems with getting that particular 'O' ring to seal consistantly so I went with the Parker P/N 2-211 (ID 0.801", Width 0.140"). Good luck - Dave
David DuBois

Is the NEMGTR Book a compilation of Technical articles? If so, since I've got a complete set of TSO's I guess I could just go look at the originals back to the 1st one (Great previous owner huh?).

Anyone know what issue the carb help I need might be in?

Thanks,
Stan Griffis

Stan - The information you want will be in the earlier issues of the TSO, as in pre 1986 or thereabouts. The keyword here is ISSUES (plural). Whenever I go searching for a specific article in the back issues that I have, I can figure on at least a half an hour of searching, and tha is with the advantage of having read the article before . It would be much easier to get the T Series Handbook from Moss or BritBook and have everything in one book. Cheers - Dave
David DuBois

Stan, your experience with a fuel leak after a fillup is the same thing that happend to me. It has nothing to do with the octane rating, it has to do with the concentration of the "summer" additive. I cannot tell you the name of it. Also you might avoid using any fuels with alcohol in them, as this can also degrade old rubber components.
According to my associate at Ford, who did a detailed study of this problem, he found the concentration levels to be all over the place. Too much of the stuff and the gaskets turn to mush.
colin stafford

This thread was discussed between 25/05/2004 and 01/06/2004

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.