Downpipe sealing ring/o ring removal

[TrevS]

Hi all

I am in the process of replacing my manifolds on my s1 4.2 which I've never done before. I've removed the old manifolds to reveal the downpipes and wanted to replace the sealing rings before putting on the new manifolds

After looking at the downpipes it seems the old sealing rings have taken to the downpipes. Could someone take a look at the picture and firstly tell me if I am correct that the shiny part at the top of the downpipe is the sealing ring and then secondly any advice on how to remove these? I guess the other option is to leave them on as they feel properly welded into place.



Any help much appreciated

[Bfastr]

Yes, that is the ring, its a soft metal and designed to crush as you tighten the flange, thats why there is a line around the middle of it. I have never opened one but I think they are hollow. replace them, they are cheap, buy an extra in case you bugger one up fitting the pipes back in and dent it. like I said they are only a few bucks each.

soak the old one with penetrant and pry it off. its a lot softer than the down pipe and should give up the fight easy.

[abowie]

Just bash it off with a cold chisel and a hammer.

[Gfhug]

Just bash it off with a cold chisel and a hammer.

Now that sounds like a typical Aussie way of doing things. Good on yer mate!

[Hugo]

I would be tempted, if it won't come off, to leave it on there & just put some paste on it :-)

[TrevS]

I would be tempted, if it won't come off, to leave it on there & just put some paste on it :-)

Did think that initially but ideally would like to put fresh seals on etc. Will have another go today with some penetrating fluid and see how we get on

[TrevS]

Just bash it off with a cold chisel and a hammer.

Well that didn't work. Managed to get in behind one of the sealing rings and down to the join hoping once i cut through it would peel off etc but it's a right mess. Chunks coming off here and there but the base of the ring is fused to the mainfold downpipe and I am worried I am going to damage the downpipe now. Will try and take a picture later but been at it for several hours and not managed to get even 1/4 of one of the rings off.

Any ideas guys?

[mgcjag]

Hi Trevor...disconect the downpipes and get them on the workbench.....

[TrevS]

Hi Trevor...disconect the downpipes and get them on the workbench.....

No sure that is an option as I don't have a lift or ramp. Any idea how easy they are to remove?

[TrevS]

OK pictures of what happened to the o ring below. I've also looked at how easy it is to remove the pipe and seems to be one large pipe that runs to just past the floor pans underneath the car. Looks to be clamped together with a couple of bolts. I could try removing this but worried that the pipe is going to be just as tough to get out as the o rings.







Thoughts?

Trev

[Hugo]

Those things are a bugger to shift - can you get in there with a rotary wire brush & dig it out? Otherwise it's just a case of worrying away at it.

[TrevS]

Those things are a bugger to shift - can you get in there with a rotary wire brush & dig it out? Otherwise it's just a case of worrying away at it.

Not sure my wire brush attachment would get through it, it's solid.

[Hugo]

Then try a bradawl perhaps? Something sharp and pointy to dig into it.

[TrevS]

Well I've exhausted my options as trying to clean up the remaining sealing ring has still left a good amount fixed on the downpipe. I think my only option is to try and remove the pipe and then see if I can clean it up any better otherwise might be easier to just order a new section of pipe and get a mobile exhaust fitter out to remove the old one and replace.

Once I've loosened the bolts holding the connecting bracket into place how easy is it to remove a section of exhaust? I am guessing exhaust paste was used so is it going to be an impossible task?

Trev

[mgcjag]

Hi Trevor..the picture you show of the exhaust looks not too old stainless.and with a newish clamp..will probably come off ok....ideally you need the car up a bit for access....make sure you put extra support in place...you dont want it slipping if your wrangling the front pipes out....you may need to whack them with a mallet...but twisting is good...all the best.. Steve

[cactusman]

Short answer...small angle grinder with a metal cutting disc....go oh so carefully so as not to graze the downpipe. Cover as much as poss of the area with a damp cloth...and old sheet with a hole cut in so the pipes poke through is great. Wear gloves and goggles...Have a fire extinguisher handy. Mine refused to budge...10 secs later...gone.. others may blanche but it worked for mine....waste of time trying to 're use old ones...

[chrisfell]

Get the car right up in the air, as high as you can get it. Then take the whole exhaust system off and work on it away from paint, engine frames, fuel and brake lines, oil and grit.

[daykrolik]

I don't mean to offend, but although in my 50+ year career of working on Jaguars I sometimes tend to "overdo things," it was always my impression it was generally the conventional wisdom to leave these alone if possible, as Hugo suggested. I have done so on several occasions with my E and not had a problem, although I do clean the mating surface of the old seal and apply a bit of paste. I am sorry you are now potentially stuck with major surgery.

[TrevS]

Well you live and learn. As with anything I replace on the car I tend to go a bit ott and order every nut, bolt etc new even though it might not be needed but as I had no previous experience I'd assume you'd replace gaskets etc when replacing a manifolds. I won't be touching the other gasket that's for sure. Will keep you posted on developments once we get the exhaust off

[mgcjag]

Hi Trevor...dont be put off.....with all these jobs they are not usually simple....its a learning curve for you.....the exhaust should have come off as soon as you knew they wouldnt tap off.....it isnt the norm to leave them on, they are a replacable part......i have changed about half a dozen pairs over the years some tapped off and some needed cutting...its the same with any exhaust fittings