where do the exhausts leak

[ssc1]

apart from the manifold to head joints that i have refaced so they are flat and fitted new gaskets and checked the manifolds for leaks ,where else can you get the ticking noise from on the exhaust system as it seems to come from the area of the main cat, its definatly exhaust and not mechanical, i have had the clamps off and checked/cleaned the mating surfaces and still cannot find a leak and i have been over the whole system with a mirror and cannot find any blowing or cracks, is there a special way that the dealers/specialists cure this apart from just replacing the gaskets again which are sound.

[2 sheds]

Common places for leaks (apart from head gaskets)
1/ "V" clamp (or 8 bolt flange) where the manifolds join the main cat.
2/ the join between "y" piece and main exhaust (beside engine) quite often the 2 pipes don't line up properly and not unusual to have a leak here
3/ manifold / "Y" piece seams can split and leak but cracks would be barely visible, look for carbon deposits.
very hard to detect /locate small leaks due to the general noise created by the cavernous manifold system
Tim

[ssc1]

thanks for that tim , i think by the look of it that its the v-band clamps as there is i bit of black soot on them, i think the older ones with the bolts are better as its easier to find a leak and seal it, v-band clamps are used throughout the avaition industry and unless they are new and the mating surfaces are perfect they leak, i was thinking of useing the red heatproof rubbery sealant to cure this ,where can i get this stuff.

[ssc1]

what is the red rubbery stuff that is used to seal the exhaust manifold joints...

[2 sheds]

Probably a silicone based product, but have never used it. try a good auto factor.
Tim