Leaking fuel light sending unit

[Tombutlercpa@cs.com]

Well, it's been one year since my fuel light sending unit has leaked, so I guess its time for it to start leaking again. As a result, I am looking for advice on how to solve the problem. I have an aftermarket unit from Abington spares with three screws on the point cover plate. In your responses please assume that it is leaking from all possible points, screws through fuel tank, gasket between sending unit and gas tank and cover over sending unit points. All fasteners will tighten down properly. The fuel tank doesn't leak from any other point. Suggestions as to sealant, gasket materials, etc., (and sources for same) are very welcome as well as any other wisdom that can be shared by the learned members of this group. I did manage to discover how to get the sending unit to maintain a good ground when the screws are all coated with glop, torque the sending unit against the mounting screws while tighten. I tightened a medium pipe wrench around the body of the sending unit and let it hang to the side. Thanks in advance. Tired of getting 10 MPG. Tom Butler

[Dean Jensen]

Tom

If the sending unit is leaking, the only fix I know is to replace it. The gasket, might try a double gasket, make sure both surfaces are clean and free of bumps, rust, etc. Wipe both sides down with lacquer thinner, use something like super silicon seal on both sides of the gasket/surfaces, thin, not to thick, do not want it in your tank. On the screws, put a very light coat of Teflon pipe dope (liquid) on the threads. The reason for using Teflon, it will seal for gas, and it will not get hard like the super silicon seal will, meaning that you can unscrew them at a later date. If you put super silicon seal on them, once it sets up you will never get them out. As to source, need to know where you are located

Cheers Dean Illinois

-----Original Message----- [b]From:[/b] Tombutlercpa@cs.com [mailto:Tombutlercpa@cs.com] [b]Sent:[/b] Friday, March 22, 2002 12:59 PM [b]To:[/b] mg-tabc@yahoogroups.com [b]Subject:[/b] [mg-tabc] Leaking fuel light sending unit

Well, it's been one year since my fuel light sending unit has leaked, so I guess its time for it to start leaking again. As a result, I am looking for advice on how to solve the problem. I have an aftermarket unit from Abington spares with three screws on the point cover plate. In your responses please assume that it is leaking from all possible points, screws through fuel tank, gasket between sending unit and gas tank and cover over sending unit points. All fasteners will tighten down properly. The fuel tank doesn't leak from any other point. Suggestions as to sealant, gasket materials, etc., (and sources for same) are very welcome as well as any other wisdom that can be shared by the learned members of this group. I did manage to discover how to get the sending unit to maintain a good ground when the screws are all coated with glop, torque the sending unit against the mounting screws while tighten. I tightened a medium pipe wrench around the body of the sending unit and let it hang to the side. Thanks in advance. Tired of getting 10 MPG. Tom Butler Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

[Locktc7440@aol.com]

I don't know about anyone else but I gave up on that sending unit years ago. The shaft where the arm for the float attaches has always been the problem area. The gas will leak into the little chamber where the contact is made and then leaks out the cover. If anyone has a solution to seal this shaft that turns approx 90 degrees I would like to hear it. The rest of the unit can be sealed but this area is hopeless. I used to resort to not filling the tank above the unit line but this can be a bother. If you don't believe me take the unit out and take the cover off (three screws) and dunk it in a pail of water so air is trapped in the cavity. It will bubble nicely through the hole where the shaft goes in. ooooo000000OOOOO just like that. I also could never see a way of dissambling the thing. I had thoughts of an O ring or something but finally gave up. I also would like a solution!!!

[Joe Gates]

... I am looking for advice on how to solve the problem ... In your responses please assume that it is leaking from all possible points... Tom I had similar problem and was advised to use shellac - worked like a dream - no leaks since I coated cork gasket material, secured unit and cover plate in place and let them set for a few days. Shellac seems totally resistent to petrol/gasoline. BUT - within days my sending unit stuck and I have not yet re-opened it up to fix - merely disconnetced the electrics. I'll get round to it in due course! See this site http://www.wwforum.com/faqs_articles/shellac.html And another use for shellac see http://www.mindspring.com/~d.g1/shellac.html. Seems a reasonable alternative means of repairing cracked Brooklands steering wheels - again, another task to be done at a future date. Hope these help Joe Gates TC 8675

[Chip Old]

On Fri, 22 Mar 2002, Locktc7440@aol.com wrote to Tombutlercpa@cs.com and...:

> I don't know about anyone else but I gave up on that sending unit years > ago. > [snip]

The shaft and it's bore were never intended to be fuel tight. That's why the small switch cover is gasketed. In use, some fuel does get into the switch compartment. If the gasket is in good condition and if the gasket surfaces are smooth, it won't leak. The catch is that over the years the cover screws get overtightened, warping the cover and distorting the area arounds the threads in the body. This makes it nearly impossible to get a good seal. Rub down (or even file) the gasket surface on the body to flatten it. Lightly countersink the threads to help prevent them from pulling up. If the cover plate is so bad it can't be trued, make a new one out of thicker steel or aluminum. Use a thin gasket, not thick cork, and gasket cement that resists fuel. Don't overtighten the screws. It won't leak. And in anticipation of the inevitable "omigawd it's gonna explode" response someone is sure to send, no it won't. -- Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E fold@bcpl.net

[Peter Pleitner]

All right Tom, here is the final solution: BTW this was the subject of several looong threads a few years ago. I gave up after having sealed those various leaks at least three times, with increasing care, thoroughness, sophistication and technologically advanced materials! Must say, each lasted longer even with a full head of fuel. But none lasted longer than a couple of years. I strongly suspect that Abingdon knew that was a bonehead design. Rather than address it (Ralf Nadar was still in law school then) they instructed the man at the end of the assembly line to never put more than 1.5 imperial gallons in those tanks. What I did the last time was - removed the tank, stripped and repainted it, removed fuel pick-up and sending units, removed the arm with bobber from sending unit, installed same without gasket, plugged fuel line hole, then poured in gas tank liner and sloshed around with plug in filler neck. I saved the liner material I poured out of tank for coating carb floats and a spare float or two. That was six or more years ago. One of these days I'll figure out how to use the low fuel warning lamp as a turn signal repeater. That function will be more useful to me. For fuel level I use the odometer and stick. Cheers, Peter

[quote] -----Original Message----- [b]From:[/b] Joe Gates [mailto:janus@iafrica.com] [b]Sent:[/b] Friday, March 22, 2002 4:20 PM [b]To:[/b] Tombutlercpa@cs.com; mg-tabc@yahoogroups.com [b]Subject:[/b] Re: [mg-tabc] Leaking fuel light sending unit ... I am looking for advice on how to solve the problem ... In your responses please assume that it is leaking from all possible points... Tom I had similar problem and was advised to use shellac - worked like a dream - no leaks since I coated cork gasket material, secured unit and cover plate in place and let them set for a few days. Shellac seems totally resistent to petrol/gasoline. BUT - within days my sending unit stuck and I have not yet re-opened it up to fix - merely disconnetced the electrics. I'll get round to it in due course! See this site http://www.wwforum.com/faqs_articles/shellac.html And another use for shellac see http://www.mindspring.com/~d.g1/shellac.html. Seems a reasonable alternative means of repairing cracked Brooklands steering wheels - again, another task to be done at a future date. Hope these help Joe Gates TC 8675 Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

[/quote]

[et1]

----- Original Message ----- [b]From:[/b] Tombutlercpa@cs.com [b]To:[/b] mg-tabc@yahoogroups.com [b]Sent:[/b] Friday, March 22, 2002 1:59 PM [b]Subject:[/b] [mg-tabc] Leaking fuel light sending unit Tom I had that problem, specifically with gas leaking around the screws. In the end it was solved using a neoprene gasket from Abingdon Spares, and small fibre washers under the heads of the screws, without lockwashers. After three years it's not leaking yet....knock on wood. Mark Evenchick Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

[Gene Gillam]

Tom wrote: >Suggestions as to sealant, gasket materials, etc., (and sources for same) are very welcome as well as any other wisdom that can be shared by the learned members of this group. I solved my cover leak by JB Weld-ing the cover to the body of the sending unit. I couldn't think of any reason I'd have to get into it so I considered sealing it a viable option. It hasn't leaked since and I haven't had a reason to get into it either. Sometimes simple solutions are the easiest... Gene Gillam 49 MG TC --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.330 / Virus Database: 184 - Release Date: 2/28/2002

[yd3@nvc.net]

Peter: I installed turn signals in an early TD that wasn't originally so equipped. I used the ignition warning light as the turn signal repeater as TD's have ammeters. I'm sure it is possible to do the same with the fuel sender. If you want, I can send the information. I've even redrawn the early TD wiring circuit to show how it's done. Blake

[Peter Forstner]

Tom, I went through that process last year. The sender unit I bought from Brown & Gammons in UK was leaking at every point it could leak. Meanwhile my TC's fuel sender unit doesn't leak any more. At least the full tank kept the fuel through the winter months. That's what I did: 1) Between tank and sender unit: I bought a gasket of a fuel resistant plastic for the TC sender unit. I has lips at every border (inside, outside, top bottom), even around the holes for the bolts. I bought it here in Germany from "Lerners Teile Service", phone +49 (2266) 6277. I got the hint from Lothar Zissel, who is also a member of this list. I also used a non-curing silicon sealing compound (hope these are the right words in English). But you have to be careful. Don't use too much sealing compound because if it goes into the fuel it could form beads and block the tank outlet. 2) Between sender unit and the bolt, connecting the wire to the warning light: Paper-gasket with sealing compound mentioned above. 3) Between sender unit and cover-plate (three screws): My old sender unit had 4 screws, the new one has 3 screws. I don't know which one is more original. Here I made a paper gasket in the shape of the complete cover-plate. Again I used the non-curing silicon sealing compound. 4) All bolts: Fuel resistant plastic washer to seal all bolts. Regards Peter Forstner - TC6325 ---------- [b]From:[/b] Tombutlercpa@cs.com[SMTP:TOMBUTLERCPA@CS.COM] [b]Sent:[/b] Friday, March 22, 2002 8:59:02 PM [b]To:[/b] mg-tabc@yahoogroups.com [b]Subject:[/b] [mg-tabc] Leaking fuel light sending unit Well, it's been one year since my fuel light sending unit has leaked, so I guess its time for it to start leaking again. As a result, I am looking for advice on how to solve the problem. I have an aftermarket unit from Abington spares with three screws on the point cover plate. In your responses please assume that it is leaking from all possible points, screws through fuel tank, gasket between sending unit and gas tank and cover over sending unit points. All fasteners will tighten down properly. The fuel tank doesn't leak from any other point. Suggestions as to sealant, gasket materials, etc., (and sources for same) are very welcome as well as any other wisdom that can be shared by the learned members of this group. I did manage to discover how to get the sending unit to maintain a good ground when the screws are all coated with glop, torque the sending unit against the mounting screws while tighten. I tightened a medium pipe wrench around the body of the sending unit and let it hang to the side. Thanks in advance. Tired of getting 10 MPG. Tom Butler Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.