ast elimination - my filler neck nipple plug solution
 

After contemplating the other solution, I decided to cut off the nipple at the filler neck, drill the hole out, and bolt it up using JB Weld as the sealant.

Here are pics/notes:

The 3/8 tap drill bit and tap set I picked up at homedepot.
http://www.myrx7.com/images/filler_neck_tap.jpg

The allen head bolt I used to fill the hole.

http://www.myrx7.com/images/filler_neck_screw.jpg

End result using a small bit of JB Weld around the bolt to make a real good seal.
http://www.myrx7.com/images/filler_neck_plug.jpg

Install Notes:

1) I used a hacksaw to cut the nipple off, from the bottom up since getting to the top is blocked but the filler neck top lip.

2) I drilled out the rest of the nipple but had my vacuum cleaner handy to suck up the metal shavings. BE VERY maticulous about trying to get the shaving to come outward, not inward...you dont want shaving floating in your coolant system. This is probably best done when you can flush the sytem or with teh filler neck off the car so you can control the shaving problem better.

3) TAKE UR TIME tapping the hole, I went to fast int he begining and stripped out the first 1/4 of the threads i made, the aluminum is VERY soft and with a wrong twist you can stipp away all the threads you just made. Fortunatly there is about an inch of threaded area there so I had plenty of thread left.

4) I used JB Weld as a 'sealant' and it only needs a little since the threads should be nice and tight, and you want to put it up towards the front of the threads so that you dont have JB Weld at the end of the bolt that is exposed to the coolant.

5) Do NOT overtighten the bolt, there is a lot of thread area there but you can easily strip the threads because the aluminum is so soft.

6) Do this mod at your own risk, I am not liable for anything, anytime , anywhere, ;)

i did the same thing. only diiference is that i used a copper crush waser...

ohhh yes, copper crush washer = good idea :-)

Looks good, however, I'd use teflon tape next time. It will seal just as well, if not better, capable up to 500F.

So what was the plan here? To eliminate AST completely?

thats why u do both. make sure theres no leaks...

yep, eliminating the ast and switching it to evans coolant....I also needed the space the ast was taking with how I want the air filter to sit.

What is the part number for the FC Filler neck for AST Elimination?

If it really strips so easily a crush washer won't help since you can't torque it much. Teflon tape or silicone is more than enough, it's only the coolant system so it doesn't see much pressure.