AHHHHH - Is stripped 3/8 NPT threads fixable.

Frank Smidler · #1 12-09-2007, 06:47 PM

I have an 0-360-A1A that was rebuilt several years ago. Up until now it has all looked good with many new parts documented. Today I removed the old, capped off, hose fitting in the accessory case that goes to the in port of the oil cooler (3/8 NPT) and found that it was stripped out. This is like getting a lump of coal in my Christmas stocking. Is this fixable? Does the accessory case have to be removed?

I will probably be calling G&N Aircraft in the morning to see what they can do.

FrankK90989 · #2 12-09-2007, 07:00 PM

Some time you can cut more threads if the original tap was not set to deep,
run a npt tap in the hole trying to catch the original threads, you can thread almost to the shoulder of the tap and still get a good seal.

AltonD · #3 12-09-2007, 07:06 PM

Pack the tap with a thick grease to catch the shavings.

mahlon_r · #4 12-10-2007, 04:47 AM

You can install a heli-coil thread insert. You will likely be able to block off the bottom of the port with some sort of plug, do the tapping and heli-coiling and then clean the port and then remove the plug you put in temporarily.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

hgerhardt · #5 12-10-2007, 11:12 PM

Are you sure it's NPT? I thought the oil cooler fittings were straight thread with O-ring. They are on my IO360A3B6D, anyway. It's either a -8 or -10 AN thread.

Heinrich Gerhardt

mahlon_r · #6 12-11-2007, 04:59 AM

IO-360-A3B6D is different from an O-360-A1A as far as the accessory housing goes. The oil cooler fittings on an IO-360-A1B6D are o-ringed and the cooler fitting on an O-360-A1A are tapered pipe thread.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."