I have a '94 FD. Installed a JDM Efini Y-Pipe some years ago and capped off hose access that used to go into the stock airbox using a rubber cap. Problem is within time the cap gets brittle like the rest of the rubber under the hood. How should I substitute this cap?

TIA

 

The port i'm talking about is the opening shown at the lowest point in the image, above..

 

Either just use another rubber stopper, or have it cut off and welded.

 

Might see if McMaster-Carr has an EPDM rubber cap of the right diameter.

I've used chair leg caps for some things near that area, like the air pump anti-moo, but THAT close to the hot side and downpipe might be a problem for the chair leg caps.

If you really want to go for it, you can get medieval. I believe that nipple is steel that's pressed/glued into the aluminum Y-pipe. Clamp the Y-pipe in a vise, hit the steel nipple with a torch to break loose the glue, and pull it out.

I was thinking that you could use a press in freeze plug, but thinking about it farther I think it would probably work its way out due to boost over time. Really the best would be to weld it shut - if it's done well, it would look really quality.

BTW, the pull the steel nipple/freeze plug trick works great on intakes that have extra nipples for airpump stuff.

Dale

 

Thanks Dale, McMaster-Carr has quite a variety of sizes, silicone, good up to 600F. I'm looking to pick up some 5/32 to replace some other worn out caps, ie) UIM nipples, etc. It looks like the largest OD they carry is 1". I'm hoping you, or others may know the diameter of the mega-nipple on the Y-pipe!

http://www.mcmaster.com/#epdm-rubber-caps/=77i1hk if anyone is interested

 

It's less than 1" I know for sure. You'll need to get the calipers out and measure to be positive, I think it's 3/4" or 7/8" (or close to it, it's metric sized of course). Measure to be sure.

The EPDM caps are relatively thin, and I just don't know how they'll deal with the heat and pressure there.

Just ran to the garage and did a quick measure - it's about 20mm in size, and HKS has some caps in that range -

http://www.hksusa.com/products/?id=848&rsku=0

The 19mm will probably be a good, snug fit. I've seen caps from the Japanese companies that were very thick and quality, that might be worth a try.

Dale

 

Sweet! those sizes are even cheaper. I'm going to make an order for 3/4" and 13/16" high temp rubber caps from McMaster just to test out. Unfortunately, HKS doesn't sell direct to end-users and although the HKS ones may be the quality I'm looking for, local authorized dealers will probably take forever to order, then charge an arm and a leg for components so small...

In the past I've used rubber caps from Autozone, I think the vendor was called "HELP!" or something like that. Impossible to google, for obvious reasons. They lasted a few thousand miles (I don't drive the car that much) so in reality I don't know how it would've held up with daily heat around the Y-Pipe.

Welding it shut is probably the best way but I have no access to people who weld, nor do I have the time at the moment to remove the Y-Pipe (I'm not lazy I swear).

Thanks again Dale!

 

You can Google HKS and the part number and find places online to order it from. Or, call HKS USA directly and see if you can just get it straight through them.

Dale

 

You could find a bolt of the right diameter, and screw it into the pipe. I little bit of JB Weld could be used to seal it if you are worried about a leak.

 

weld it...