Seems unnecessary but wanted to check with those who've gone before me.

 

They want you to replace them whenever you remove them, like a torque to yield bolt (although perhaps not for that exact reason), however I've reused them with no consequences.

 

Yeah, at $80/pop I'd rather try to reuse them too. https://www.roversnorth.com/parts/wa...r_discovery_ii

 

I've reused them without issue. Can't really thinking of any legitimate reason why you shouldn't be able to.

 

The only reason I think they say to replace them is the high temp thread sealant on the head side of the adapter applied by the factory is one use only. Of course you can just reapply a little before installing.

 

Any recommended sealant?

 

I didn't use any. Unlike a spark plug, which has a compression washer, there is no such washer to keep the SAI adapter from backing out of a head under heat cycling and vibration. If you've every had an improperly tightened spark plug loosen and pop out while the engine is running, it can be a violent event. It does happen. I have to assume that for this reason the factory uses a threadlocker on the SAI valves, which you can see in the pic of the new one in that link. All that said, since the other end of the SAI adapter is held fast by the union nuts at the air pipe, the chances of loosening are further reduced. As long as you haven't wire brushed the SAI adapter bare before reinstalling it, I think you're going to be fine reusing it. Just make sure you get them torqued correctly, the rave calls for 24 ft/lb on the adapters and 18ft/lbs on the unions (union threads lightly oiled first). Interestingly, it also recommends cleaning out the head bores with a 5/8-20 tap before installing new SAI adapters, presumably to remove any traces of leftover threadlocker. I didn't do that either and in almost 20k miles everything has been fine.