"It might be easier to find an 11/32 drill bit. That will work too, on an 1/8 NPT tap."
5/8 yes but that extra 1/64 from the ideal 21/64 is your leak. Loctite might burn at ~1300, and JB ???
Helicoil maybe?

 

Well the exhaust manifold is ruined unless I canre-tap it to a larger size and use some type of adapter. I have torqued it down and pretty much ruined the threads. If I didn't have the exhaust brake this would not be a problem. It only does this when the brake is on.

 

The question I have now is...will the truck make a 6 hour trip this weekend if I don't use the exhaust brake? or will it get worse and eventually blow the probe out of the manifold???

I know that there is a considerable amount of back pressure when the brake is on, but what about when it is off and you have normal exhaust flow?

 

Today's only Wednesday ... you've got two whole days to fix it before the weekend. Get outside and GET CRACKIN !!!



If you are worried about getting shavings in the manifold again because you're going to a larger hole, why not do like Jake did and weld a pre tapped spacer on the manifold and call it a day? I'm sure if you didn't feel comfortable welding it on that a welding shop or a exhaust shop could do it for ya.

OR

How about taking the probe out entirely and just screwing in a plug until you have more time?

 

Can you weld to cast iron?

 

Jake did it. He welded onto his turbo elbow

 

Can I weld to cast iron? No. Can it be done? I don't know. I once had a buddy that said if a magnet would stick to it, then he could weld it. The pretapped weld sounds like a good idea, where do I get one?

The only problem with a plug is, that it is the same diameter as the probeand it will more than likely leak too.I think I started out with a drill bit too big.1/64 inch doesn't sound like a lot but when the manifold heats up to 1000+ degrees, it expands enough to start leaking. Normally this wouldn't be a problem, but with the added back pressure from the exhaust brake, it leaks.

I've basically got from 5PM tomorrow until bed time to get it fixed before the weekend.

 

Jake definately welded onto his elbow,I remember.

Autometer sent me a bushing that could be welded onto the elbow as well, so I'm sure it can be done. The bushing wasn't tapped, but you could always pre-tap it prior to welding it on.

 

Took me a while to find it ( I've got WAAAAY too many pics saved ) but here is Jakes set-up



[IMG]local://upfiles/42139/AE3F7747DD7848DCB910D2A3ABC88FF7.jpg[/IMG]

 

http://www.turbowholesale.com/produc...productid=9581

It looks like you may be able to pick one up at a autozone etc the link above has the autometer part number. And I stand corrected, you can stick weld cast iron. I was thinking if your threads are still a bit there, maybe you could put a little aluminum foil on the probe threads to seal it up a bit, kind of like hi temp teflon tape, just a thought