J-Pipe Questions

[Roger65]

I am installing a new cat and J pipe and have a few questions. Engine is 2.1 wbx. I did a search and found some answers but the loose flange connectipns on the J pipe have me a little worried cause I've never used them before. Specifically:

1) Is it easy to over torque and damage or ruin the flange
2) collector end gets metal donut, cat end gets metal gasket, do I use any copper sealant or other goo on either end?
3) What's with all the washers on the J pipe bolts, the Bentley lists them as some kind of compression spring?

Any other general advice or stuff to watch out for on this job?

[T3 Pilot]

Before you do anything, loosen all the fasteners from the cast iron Y back to the muffler brackets. This will give you the wiggle room needed during replacement. It would be unlikely that you could over torque the new fasteners at the flanges to the point of damaging the flange. The bolts would probably snap first.

I swapped out the steel donut for graphite impregnated fibre on my last replacement. Donut at both ends helps in aligning things.....

I think all those washers were the solution to the problem of keeping the nuts tight. The high heat renders a normal lock washer useless in this application. Use exhaust lock nuts instead of all those washers.

You should still get under and re tighten things after a few heat/cool cycles.

Good luck.
_________________
1988 Vanagon

The most important part in every vehicle is the nut behind the wheel......

[Roger65]

Thanks for the reply. It was mainly bending the pipe where it is flared to hold back the loose flange that had me worried. I feel better now, knowing there is no risk of unflaring that pipe by over tightening

I do have two donuts, where did you find the fibre ones. Sound like they would seal with less force than the metal ones I have.

[Wildthings]

I worried a bit about this system when I first saw it, but it has worked quite well over the years. I would not look for a softer donut, the stock one is fine.

[T3 Pilot]