Temperature Sender Thread Repair

[Tim Genovese]

The aluminum temperature sender threads on my L-78 intake are in bad shape. I used a generous amount of teflon tape previously but that fix only worked for a short period of time. I'm looking for a permanent fix. Any suggestions?

Thanks.

[Gene M.]

Re: Temperature Sender Thread Repair

Tim, Devcon makes an aluminum filler that can be machined and threaded. Good tooling supply houses carry it. I think it is actual aluminum particals suspended in an epoxy. It's a two part mix.

[Gary F. LeDuc]

Re: Temperature Sender Thread Repair

Do they make a helicoil insert that size? If so that would be a "perminate" fix.

[Tim Genovese]

Re: Temperature Sender Thread Repair

I just placed an order with a local supply house for an aluminum puddy product made by Devcon that can be machined and threaded. The cost is $32.00 for a 1 lb. can. Enough to last me several lifetimes.

Thanks Gene.

[Mike M.]

Re: Temperature Sender Thread Repair

Gene, I've used a similar product called Metalset A4 which can be bought at aircraft parts supply stores usually. When fully cured it can be machined and tap with no problem. Mike

[Joe L.]

Re: Temperature Sender Thread Repair

Tim-----

I don't think that you can use an epoxy type repair material for this application. I believe that the temp sender brass body grounds through contact with the intake manifold. In fact, I don't recommend even using teflon tape on temp sender threads.

If that's the case, your only options would be a Heli-Coil-type repair or heli-arc welding and redrilling/tapping. I don't know if thread repair kits are available in this size or not. If I recall, these threads are 1/2" NPT.

[Ed Jennings]

Re: Temperature Sender Thread Repair

Tim, I agree with Joe, anything non-conductive will likely cause the temp sending unit to fail to operate or operate inaccurately. NPT threads are tapered, unlike bolt threads. Sealing is accomplished by a "crush fit" between the two metal surfaces. Pipe "sealer" is actually a thread lubricant to help accomplish this crush. If your threads are not too bad, you might be able to run a tap through the threads again and seat the sender a little deeper. If this fails, then you won't have lost anything. You will still be faced with a weld/drill/tap situation.