How to remove Exhaust Silencer?

[acdbox]

Hi,

My exhaust silencer has severly rusted and needs replacing. Though am struggling to work out how to remove it? Any pointers are appreciated.

Thanks

Andreas

[bizzard]

Hi,

My exhaust silencer has severly rusted and needs replacing. Though am struggling to work out how to remove it? Any pointers are appreciated.

Thanks

AndreasIMG_2180.JPGIMG_2179.JPG

Looks like an old Lister Burgess set up. Undo the flange nuts and bolts at either end and then separate it by undoing the big nut couplings.

[Batavia]

Unbolting the two flanges will be you best starting point - probably much easier than trying to undo the unions.

 

Chris G

Edited July 28, 2016 by Batavia

[BEngo]

Angle grinder?

N

[acdbox]

Hi,

It's a BMC 1.5,

Just to be clear what exactly are the flange section? Is it the circular steel joint with the 3 smaller bolts, if so that is only on one side and not both. Haven't got a spanner large enough for the union sections + very heavily rusted so may not budge.

 

Yes, Have an angle grinder but where to cut to preserve an easy replacement?

 

Obviously you can guess I'm learning as I go here.

Thanks again

[BEngo]

The flange is the bit with bolts to the right of pic 2179. Undo those bolts and the flange should separate. It probably won't move much if at all because it appears there isn't much room for it to move.

 

It looks like there is a union fitting between the flange and the silencer and the left hand side also looks like a union fitting.

 

You really will need to buy or borrow a stilson -preferably a big bugger. At least a 24 and probably better a 36 because you need the jaws to go on the union nuts. IIRC you can probably hire them. Even the biggest adjustable ever will not be any good because the nuts are so rusty.

 

Soak both unions in diesel or proper penetrating oil (not WD 40 which is useless for this job.) Well soak some rags in the oil/diesel and wrap round all parts of each union and then cover with cling film. Leave for a week or so. Top up the diesel/oil occasionally, if you can.

 

Remove rags etc and run the engine to get it all really hot. Help things along with a really big blowlamp on the unions if you have one. Red hot is good in these situations, but don't set yourself/the boat alight!

 

Apply stilsons, adding leverage from a scaffold tube over the handle as needed. I think the LH nut screws to the left and the flange end nut goes toward the flange, but would need a better photo to be sure.

 

If not successful cut the pipes as close to the silencer as possible and tackle each union nut separately. (At this point easy replacement is no longer likely!) The nut attached to the flange can be attacked in a vice and it may be possible to split the union fitting itself(not just the union nut). You want to recover the flange but everything else is expendable.

 

If all else fails split the two union nuts with the angel grinder and then apply stilsons if it hasn't fallen apart.

 

 

In the worst case you will have to renew everything between the flange and the hull outlet.

 

Pipeline Center, or a proper Plumbers Merchant (not a shed) are your best bet for new union fittings and the barrel nipples which go between the flange and the unions. Assemble everything with generous dollops of copper grease- that way it might come apart more easily in future.

 

N

[gazza]

Beating the living daylights out of rusty unions can help shift them.

 

You need two pairs of Stilons BTW.

 

Putting a piece of tube over the handle of your Stilsons will end up jarring your wrist when the union lets go.....

 

Rothenburg grips are superior to the old Record stilson stuff.

 

I disc the lot off and start again.

There isn't too much money in those fittings.

Edited July 28, 2016 by gazza

[Cheshire cat]

If you have an angle grinder I would attack the bolts on the silencer side of any joints. A new silencer will be available to match the old one and bolts are available from a variety of sources. Trying to undo the large nut will be a waste of time in my opinion. I have just swapped out a silencer that was far "cleaner/newer" than yours and it wouldn't budge.