10 replies to this topic

[mini1976]

As the descrition says. I have a lcb but just cant get the y piece to seal. I have tried gum gum when putting it together, changing the bolts in the clams i just wondered if any one had any tips on getting it to seal as the gum gum just cracks off and the claps sone seam to creat a seal.

[Bungle]

try a blob of weld

[mini1976]

But if i weld it i wont be ever able to get the maniflod off the engine will i? WIthout cutting it off?

[Pavel]

I'm assuming bungle means weld the Y-piece to the LCB manifold, don't weld it to the rest of the exhaust system. This SHOULD still allow you to remove it from the car, although I'll let him answer that question to be certain.
This may be obvious but is your LCB and y-piece the same bore? (did you order them as a package?)

[mini1976]

As far as i know they are the same bore, it came fitted to the car, i replaced the engine and have just never really got it to seal since. They are a snug ish fit but it stull blows a bit all the time. There is some presure if you put your hand over the end of the exhaust but you can hear it blowing all the time and makes the car really noisy

[Pavel]

I'd give it another try with paste, make sure to put the paste on properly on both pipes (i know some people say to put it only on the one end, but I've had a lot more luck putting it on both), then tightening everything up and leaving it to seal. You don't need a LOT of exhaust seal (that'll just cause it to crack off), you just need to make sure its on there nice and snug.
If it doesn't work, I'd weld the y-piece to the mainifold. I've got a 2 branch manifold combined with y piece, and that came off my car (don't remember how but I believe I dropped it together with the rest of the exhaust system rather than lift it out from the engine bay, so i'm 99% sure you'll be able to remove it without any trouble, but as my manifold is just some dodgy one rather than being exactly like the LCBs out there, don't take my word for it!

[mini1976]

ok ill give it another go, Is it possible to get new clamps for the Y piece as i wondered if they might have streched. If i still cant get it to seal imm try and remove it in one piece as if i can do that then i should be able to do it when welded up.

[floatintoast]

lol u sound exactly like me 2 months ago, i had this problem but whatever i tried it wouldnt fix, spent hours on it so got quite a bit of info, might be useless, might not...

Firstly if your using the old exhaust manifold clamps (the circular ones) dont even bother, they dont tigten up enough and badly warp when tightened up. Instead buy some U Clamps/bolts which give a perfect fit, i needed 45mm clamps for a 2"exhaust system, keep trying them out until u get the right size so that it comes into contact with the whole of each pipe.

Secondly make sure the rest of the exhaust is well supported, luckily my dad works with steel fabricators made up some custom exhaust mountings. If the exhaust is not well supported then the movement of the engine while driving will soon loosen the seal. Also make sure the manifold is as far into the y piece as possible, i slackened the manifold at the engine and blocked the two pipes with wood so they wouldnt move and hit the back of the engine and hit the rear of the exhaust (not directly put a metal plate inbetween hammer and exhaust)with a large sledge hammer, not only did it relieve the stress of having to fix the seal for a 4th time it pushed the pipes right into the y-piece - just be careful your not doing any damage and stop hitting once the exhaust has stopped moving. Having someone else check for movement is very helpful.

Thirdly to seal i used a combination of exhuast putty (really thick grey sticky stuff seemed to work the best -like marmite/honey) and the exhaust webbing/tape you can buy to cover holes in the exhaust. (i bought gum gum bought found it was too hard and never bonded with the steel very well) Once the Y-piece is in cover the exposed exhaust with the putty so it makes a light seal then smear the putty over the webbing and lay putty side down and rap as tightly as possible around each pipe/y-piece end. Then place the clamps over the webbing and tighten fully.

Hopefully that might be of some help, i had all sorts of trouble with mine and it has worked a treat. If u want ill have a look at the make of putty i used but there are plenty of types - the one mentioned above worked the best.

si

[mini1976]

I found or at least thought that there wasnt enough room for the u bolt types of clams on the Y piece to down pipes (which is the bit i cant get to seal). I have fitted one before but then it didnt look like there was room for a second one? Did you manage to fit them in there?

I found or at least thought that there wasnt enough room for the u bolt types of clams on the Y piece to down pipes (which is the bit i cant get to seal). I have fitted one before but then it didnt look like there was room for a second one? Did you manage to fit them in there?

[floatintoast]

yeh got them in fine. well had the bar that connects across the bolts facing the floor so that just the bolt went around the manifolds, and staggered them - they wouldnt fit side by side so one was slightly infront of the other. Yeh i had the same problem with the manifolds/downpipes connecting to the y-piece. can take some pics of the set up tomo if u want - need to get under there anyway just to check everything is still ok

[Bungle]

But if i weld it i wont be ever able to get the maniflod off the engine will i? WIthout cutting it off?

i ment just a small blob of weld

that will stop i moving apart but if you ever want to take the manifold apart then a hit with a hammer and it will crack and come apart easy