I installed a fuel gauge about a week ago and all was well. Today it got about 90 degrees outside. Now my line from the isolator to the gauge is leaking. fitting are snug with teflon tape on threads. it's one of them cheap plastic lines with the ferrels. has this happened to anyone else and what is the solution?

also what do you put in the line? i have rv antifreeze.

 

It might be the tape. The fitting should seal with just the pressure of the ferrel against the taper of the female part of the fitting. Doesn't take much and they usually seal pretty well. You might try getting rid of the tape. Turn the key on / off to start the pump with the fitting loose at the isolator to fill the line. From the top of the isolator to the guage use the antifreeze.

 

the tape is on the 1/4 inch adapter. the 1/8 ferrel fitting does not have tape. will check and see if plastic line has cracked at ferrel tomarrow.

 

Leaking compression fittings are very common if overtightened.
When you take it apart I'm sure you'll find the ferrule massively distorted or even the top of the nut cracked..
Buy new ferrule(s) or nut at any auto parts, cut the old ferrules off and tighten the nut finger tight plus one turn of the wrench next time.
The tape is is totally unnecessary on a compression fitting but shouldn't hurt anything.

 

did not put tape on compression fittings, tape is on the 1/4 adapter on isolator and threads on 1/8 fitting to adapter. no tape on the compression side.

i put about another quarter turn on the 1/4 fitting and refilled the tube with antifreeze. was not leaking at the compression fitting. will see how things go.

 

Hope u used the yellow teflon tape.