Chevy Tri Five Forum banner
1 - 20 of 26 Posts

·
Registered
Joined
·
418 Posts
Discussion Starter · #1 ·
I replaced the sending unit gasket a while back with one of those cork ones from the guy we all buy one from.

Used the correct Permatex goop, bought new brass washers (albeit not the "correct" ones), permatexed under the washers before fastening, and pulled it down evenly.

Fill it up for today's cruise and pull in the garage after we're done.

Go back out in the garage later and telltale gas smell. Slide under - I figured it had to be the filler neck but it is dry as a bone. I'll be danged if it's not leaking around the washers a tiny bit. Only a little, but as you know with gas smell a little goes a long way.

I'll get it properly up in the air and check but I'm not sure what I did wrong in that sequence. I took my time to make "this the last time I'm messing with it" when I replaced it.

Oh well....don't want to get spoiled with everything working perfectly.

Any ideas??
 

·
Registered
Joined
·
11,220 Posts
I replaced the sending unit gasket a while back with one of those cork ones from the guy we all buy one from.

Used the correct Permatex goop, bought new brass washers (albeit not the "correct" ones), permatexed under the washers before fastening, and pulled it down evenly.

Fill it up for today's cruise and pull in the garage after we're done.

Go back out in the garage later and telltale gas smell. Slide under - I figured it had to be the filler neck but it is dry as a bone. I'll be danged if it's not leaking around the washers a tiny bit. Only a little, but as you know with gas smell a little goes a long way.

I'll get it properly up in the air and check but I'm not sure what I did wrong in that sequence. I took my time to make "this the last time I'm messing with it" when I replaced it.

Oh well....don't want to get spoiled with everything working perfectly.

Any ideas??
When you say "albeit not the "correct" ones", how so? Diameter ID too big?
 

·
Registered
Joined
·
912 Posts
I used Permatex thread sealant on the threads of each screw too. My sender was leaking at the fitting where it is soldered and I had to take it out and fix it. The cork gasket dried up and was worthless. I went to NAPA and bought some good rubberized cork gasket material and made my own. I also scuffed both sides of the sender with some Scotchbrite to give it some "bite" like some others have recommended. The darn thing had been leaking all summer and I finally figured it out. I am not so sure that the cork gasket was as good as the one that I made. So far, so good.
 

·
Registered
Joined
·
418 Posts
Discussion Starter · #4 ·
When you say "albeit not the "correct" ones", how so? Diameter ID too big?
I bought some brass washers from the local box store. The overall od was small enough to fit within the confines of the sending unit. I don't remember the od of the hole relative to the screw although I don't recall it being overly large. Is it intended to be snug and seal or provide a wider clamping surface (or both)?

I put sealer under each before clamping. I'm sure some got on a little of the threads, perhaps I should have used it like thread sealant? I was reluctant to do that because that permatex is pretty sticky stuff. I didn't want it to be Permascrewed in.

The cork gasket was the one from the guy we all buy from off Chevy talk. It was thick and a very nice unit.

I'll get under it and closely inspect where it's coming out.
 

·
Registered
Joined
·
164 Posts
My sending unit is not A-1 but I'm not going to mess with it, after reading all this.

I'll just fill it up once a week and I should be good!:bowtieb:
 

·
Administrator & Tech Articles
Joined
·
52,858 Posts
TX....You keep saying "brass washers".....I thought they were supposed to be copper. :confused0006:
 

·
Administrator & Tech Articles
Joined
·
52,858 Posts
Pure copper is a softer metal and will seal better than brass.

Brass is made of a combination of copper and zinc....Changing the amount of copper and zinc can make brass harder or softer.
 

·
Registered
Joined
·
418 Posts
Discussion Starter · #11 · (Edited)
Alright I just looked at the screws online and the washers I used were definitely not that snug around the threads. I just need to order some and be done with it. I wonder if I can just get the washers and use my non-clutch head screws?

I would've thought the permatex under the washers would have sealed off decently?

What size are the clutch heads? I know I don't have a clutch head screwdriver.
 

·
Registered
Joined
·
912 Posts
My screws in the kit that I got are phillips head and they came with the copper washers. It shouldn't matter if they are clutch head or not. Like I said, I used thread sealant but that was just my way of doing it and it is not necessarily the right way. I just thought it was the right thing to do with the screw holes open to the inside of the tank.
 

·
Registered
Joined
·
418 Posts
Discussion Starter · #13 ·
Well got under there today and it appeared to be leaking past the stud where the sending unit wire connects. Tightened that down, wiped it all down and came back later and it was definitely coming out a micro crack where the fuel line is welded to the unit.

Fortunately I had another unit I had bought and swapped them out. I re-used the cork gasket which may not be advisable but thought I'd give it a shot. Used Permatex #2 between the sender stud and washer, on both sides of the cork gasket, under each screw and on the threads.

It wasn't leaking when I finished and put the gas back in but I thought I'd need to give the great migration time to work before I proclaim success.

I hope I didn't just jinx it!
 

·
Premium Member
1957 Chevy Bel Air Convertible; ZZ4 w HEI ign; 700r4; 9" rear w/3:50 gears; pwr disc fr w drum rear
Joined
·
1,996 Posts
I got a set of screws with copper washers from Danchuk and seem to remember those little copper washers were on there so tight around the screw, I couldn't have pried them off. (not sure how the heck they get them on there!) I also put the Permatex 2 on the threads. Mine has held for the past 8 mos.

Sounds like the screws might be a weak link. (if it doesn't turn out to be the line weld)

Ace
 

·
Registered
Joined
·
6,561 Posts
The screws on

the sender in my Rock Valley tank have rubber seals on them. Not sure if they are the same thread as a stock tank... Might be worth a look to see if you can use them...
 

·
Registered
Joined
·
488 Posts
i had this problem, i made a gasket out of rubber and reinstalled the sending unit and i have not had another issue since.:anim_25:
 

·
Registered
Joined
·
4,842 Posts
yup, rubber gasket. and it does`nt matter what the washers are made of. the washers are not sealing it. the washers are just evening out the pressure. the rubber gasket is the "seal". right?
 

·
Registered
Joined
·
488 Posts
yup, rubber gasket. and it does`nt matter what the washers are made of. the washers are not sealing it. the washers are just evening out the pressure. the rubber gasket is the "seal". right?
the rubber is the seal and like you said the washers are to even the preasure, all i can say my gas does not leak, now if i could only say the same for myself,:sign0020:
 

·
Registered
Joined
·
418 Posts
Discussion Starter · #20 ·
GGGOOOOAAAALLLLL!

This is where y'all picture that 'ol boy that calls the soccer matches and hollers "goal" for 30 seconds....

Just crawled under it and it either isn't leaking any more or it's leaked all out past the spot and it's not fixed.

I'm going with fixed for now. It would have stunk up the garage like whodunit last night had it kept leaking and didn't.

:tu

On to the next fix!
 
1 - 20 of 26 Posts
Top