Installing Transmission Lines in radiator coolant tank

[1KWIKSIX]

Am about to install my new ALRADCO aluminum rad and wondering if the 5/16" x 1/8" NPS brass 90 degree elbows that connect the lines to the rad coolant tank require a alight amount of teflon paste to seal? Since they are NPS thread....I am thinking they do.

Can anyone please confirm.

thanks,

dave

 

[SSedan64]

Yes, use it.
NPT/NationalPipeThread are self sealing but, the Paste will aid sealing & lube the threads.

 

[1KWIKSIX]

Yes, use it.
NPT/NationalPipeThread are self sealing but, the Paste will aid sealing & lube the threads.

The 1/8" thread does not appear to be a tapered thread (National Pipe Taper) but looks to be a straight thread (NPS).
Bought 2 replacement 5/16 x 1/8" 90 degree elbows, which are identical to the OEM ones taken out. They didn't appear to have any reminents of teflon on the original threads. Can't figure out how these 1/8" threads would seal unless a thread sealant was used.

 

[SSedan64]

No O-ring or Washer Seal? That's normally how the Straight threads seal.
Part like #12 here >> http://perfauto.tripod.com/data/4-096.pdf

 

[1KWIKSIX]

No O-ring or Washer Seal? That's normally how the Straight threads seal.
Part like #12 here >> http://perfauto.tripod.com/data/4-096.pdf

No "O" ring used or sealing washer on this. I've got the original 90 degree brass 5/16" inverted flare x 1/8" threaded fittings and they are simply a straight thread.
Thanks for the drwg. It also doesn't show any "O" ring or sealing washers used.

Dropped in to a transmission shop in my area today and spoke with the owner....he confirmed that on a straight thread they would use a small amount of teflon paste to seal. Thinking that's what I'm gonna do.

Thanks for your help / suggestions.....much appreciated.

dave

 

[1KWIKSIX]

I stand to be corrected.....looks like the 1/8" threads are tapered (NPT) after all.
Was difficult to see because it's such a small diameter...but took my digital vernier caliper and discovered that it actually is a tapered thread.