Exhaust back box change

[gman88667733]

My Fiat Panda needs a new back box as it is rattling like crazy and does not sound good at all.
The current one has obviously been replaced at some point as they cut the old one off and then just fed the new part of pipe over the top with some paste and then a thin U clamp over the join.

For me to replace it, can I simply just unbolt the clamp and try to pull the section attached to the back box out and then reapply some paste when I reinstall? Will the old paste make it difficult?

Never done any exhaust work before, so just want to make sure.

Cheers

[E-bmw]

Yes, you can, you may need to also carefully part cut through the outer pipe to release the hold of any rust/paste build up between the 2 pipes so that you can remove it without damaging the other pipe.

When you get it off & before applying new paste go over the existing pipe with a file to make sure it is smooth enough to slip in with the new paste rather than rough & rusty which won't go in as easily.

[gman88667733]

E-bmw said:

Yes, you can, you may need to also carefully part cut through the outer pipe to release the hold of any rust/paste build up between the 2 pipes so that you can remove it without damaging the other pipe.

When you get it off & before applying new paste go over the existing pipe with a file to make sure it is smooth enough to slip in with the new paste rather than rough & rusty which won't go in as easily.

Thank you.
I assume the pipe that is connected to the new back box will already be designed to be a larger diameter than the pipe it mates to that it fits over it?

[Oldandslow]

After a quick trawl of ebay it looks like the back box is designed to fit with a slip joint so replacements have an enlarged diameter section intended to slip over the pipe from the mid section.

[paintman]

gman88667733 said:

Thank you.
I assume the pipe that is connected to the new back box will already be designed to be a larger diameter than the pipe it mates to that it fits over it?

That's usually the case.
Use plenty of paste to ensure the joint is sealed as leakage can adversely affect the MOT emissions test.
Often best to replace the clamp as well, they have a habit of the nuts seizing & you think the nut is a bit stiff so give it a bit more welly & it shears off.

Edited by paintman on Friday 27th March 10:09

[redandwhite]

once you have the U clamp bolt undone, rather than pulling it towards the back of the car, grab the exhaust by the hangers and twist the exhaust left and right whilst pulling - should help break the seal and easier to remove.

Get some high temp silicone rather than traditional exhaust putty, will provide a better seal.

WD on the exhaust rubbers will make removing them easier too, good luck!

[gman88667733]

Thanks everyone, that helps a lot.