Re: [Chrysler300] 300D gas tank question
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Re: [Chrysler300] 300D gas tank question

Tom, Sounds like it was put together all  wrong. There is usually a rubber ring on the underside of the fuel gauge sender disc, kind of press fitted into a groove made there just for it . Looks like a square o ring ? Mine was In good shape .....  if ok — again —-clean mating surface thoroughly and grease ; or good alternative there , no grease , dry ,  might be red rtv , permatex , good stuff ? No gasket on top of the sender disc —- that obviously does nothing. 
An aside, after much difficulty over many years mainly with 30’s Packards , ——rust and crud from tank fouling the fuel pump inlet valves at the worst possible times  , ( Easter Sunday with Family , everyone all dressed up, 25 miles from Home) and also experiencing restricted flow at WOT due to clogged sock on mopar , I have been removing sock mesh,( leave inner core)  putting 3/8 by 3/8 or 6-AN with 3/8 hose adapters  large area hi flow stainless mesh filter outside of tank . Made for alcohol drag race cars . Maybe 60$ at Jeg’s . It comes apart at ends  to clean it , about 4” long by 1.5 diameter . Moroso makes one too . Then no need to get into Tank or sender / sock . Crud ends up where you can get at it . Not for pristine tank and high point restoration, I know,  but good for a real driver . I was afraid regular gasoline fuel filters restrict too much on suction side at high flow. But Work ok too , to a point , installed like this . Wix makes good plastic ones you can see into ..  Better than dead at side of road , prospect of pulling / draining tank . 
Hope this helps,

Sent from my iPhone

On 6 Jan 2018, at 11:06 am, Tom Chvapil <tomchvapil@xxxxxxxxx> wrote:

Hi John, (and everybody that posted a reply to my questions)

Thanks for taking the time to explain things.

The sender seems to work fine (I ohmed it, as well as tested it out of the tank, hooked up to the gauge, and all positions on the sender correlated with the gauge, so I guess that part is OK. Looks like somebody changed the cork and put a brass float on the unit.

It had a rubber (I think, it was in such a bad shape that it totally disintegrated) gasket between the float/pickup tube flange and the ring that locks it in place. Is rubber the correct material to use, or should I go with cork gasket? And, I think that the gasket should be between the tank and the float flange, right? Not the way they had it….

I will go look at the tank and see if the o ring seal for the filler neck is there and what kind of shape it is in. Probably will replace  that, no matter what condition it is.

I have a lot of 30s (and other) cars, so I know about the ground importance for the sending unit. I guess it applies to any car, but I always solder a short jumper between the sender and hook that up to a clean ground screw on the frame.

Again, appreciate your input,

Best regards


On Jan 6, 2018, at 7:01 AM, John Grady <jkg@xxxxxxxxxxxxxxxxx> wrote:

Hi Tom There is an o ring where the filler pipe slides into the tank ;in a groove in the tank .  usually in pretty good shape , but can get new one. Judgement call . Do not use o ring from cheap kit in red o ring box. ( China) Must be gas resistant . .. Possibly grease the pipe after thorough cleaning ( front end grease ). 
How is the cork ? I recently replaced the cork with Ford style little brass tank gas float by using # 12 building wire solid, and solder , cut off arm wrap loop around brass tank groove. Clean arm end till shiny wrap wire around it and solder   . I also soldered quickly to little tank . Cork can sink . Has to move in same arc thought center of float . Check sender with ohm meter , not the same ohms as common later (60 up) thermal gauges.( 10-90)  Mine was 20 to 200 ohms . It was ok , but corroded connection . I also solder a ground wire to the gas exit pipe where it leaves flange and ground that to car sheet metal . Common problem with fuel gauge is poor connections here . 

Sent from my iPhone

On 5 Jan 2018, at 5:53 pm, Tom Chvapil tomchvapil@xxxxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx> wrote:

Good morning,

We pulled the gas tank out yesterday (to fix the pick up tube sock and sender), and in the process the filler tube separated from the tank. Is it designed to do this, or should it be part of the tank?
If it is separate, is there a seal or??? that needs to be used to make sure fuel doesn’t  leak out when filling the tank, or bouncing on my dirt road with the tank full?

Any input will be appreciated. 



Posted by: John Grady <jkg@xxxxxxxxxxxxxxxxx>

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