Teflon Tape Object Lesson

[zupanj]

Well this is a little embarassing. I have been using Teflon tape for years with no problem. I have also heard many people say it is a bad idea to use it because it shreds and clogs up lines. Most people now recommend teflon sealer. Anyway I was installing new fuel lines on the RR and ran into a problem getting the flanged tube to seal at the fuel pump fitting. I had the fitting off five or six times and used tape on it most if not all of the times. Gave up on the flanged tube and used rubber tubing with a barbed fitting and more Teflon tape. Took the car out to see how it ran because I also reset the timing. Got about two blocks and the engine died when I put in the clutch at a stop sign. It started back up and ran very rough below 3000 rpm. Got it back home thinking something horrible had happened even though I was sure it had to be simple. Walked away from the car last night and just slept on the problem. Woke up this morning pretty sure it was a plugged fuel filter. Took the filter off and changed it out. Took the fitting off the fuel pump and ran a couple of revs to flush fuel into a can. There were several strands of Teflon tape in the fuel. Put everything back together and the car started right up and idled fine. I guess I will use Teflon pipe dope exclusively in the future.

Jack

 

[A4572]

When using Teflon tape do not cover the first threads,also it is not intended to be used on flare type connections.

 

[Basketcase]

not bashing by any means, but why do you feel the need to use anything on your fuel line? Are you using a hi po line? I've never needed anything than old stel line and rubber hose, so I've never used any sealer.

 

[zupanj]

Didn't use it on the flare fitting, only the NPT fitting into the fuel pump. NPT fittings are supposed to have some type of sealant. Also I usually don't cover the top thread but I had the fitting on and off so many times that I think some of the shredded tape fell into the fuel pump.

 

[george68hemirr]

jack ...glad to hear you fixed the problem

 

[Hoosier Bird]

In our hydraulic shop, we never use tape. If it gets to the pump or the valve it creates very hard to find issues.

 

[dstryr]

I like to put a little grease on the shoulder of the flange so the nut does not bind on the flare as I tighten it. I tighten and loosen the nut a few times to get the flare to seat. The grease will help prevent the line from twisting as you tighten it, which could cause the the nut to loosen if the line 'unwinds'.

 

[wannarunner]

Good idea.....

 

[Basketcase]

on steel brake lines I put a small bit of never seeze.

 

[zupanj]

Good ideas you guys.

Jack