ahhhh.. I see.. sneaky, hugh? you hope. been there. it holds only yey long. should have used plumber tape on them. or, even regular thread, soaked in grease, or waxed thread, in-between the threads.

 

Plumber's tape. You're kidding, right?

 

nope. dead serious. they do have oil and petrol resistant tapes. gas resistant(yellow). I use regular teflon tape on my cars oil drain plugs. Never had an issue.
I, also, use red and blue sealant routinely, and am quite familiar with it. It is not designed to seal threads, only more or less flat surfaces. You can use bronze one too, on engines, for head gaskets. Still - it's surfaces, not threads. By the time you screw anything with it on in, it's basically gone off threads. For what it is, Loktite would have been better choice, as it's liquid.
Also, keep in mind, that if that sealant cakes, you will have heck of fun removing those tubes next time.

 

I didn't know about the petrol resistant tapes. Are they suitable for high temperatures?

 

well, engine head does not really get that hot... if cooling is working.

PTFE Teflon Tape products, buy PTFE Teflon Tape products from alibaba.com

Product Name :PTFE Teflon Tape
Temperature Range: --170 to 260 Celsius degree
Fluid sealing: 200(kgf/cm2)
Gas sealing: 140(kgf/cm2)
Color: white or colorful
Packing Details:10pcs/box ,500pcs/ctn
Usage :Widely applied in construction machinery, chemical industry and other areas, especially in pipe linking systems such as buildings . in addition it is also used to seal pipe threads being joined together for plumbing purpose.