How to disconnect Y-pipe from manifold?

[CraigK]

My '87 Bronco II 2.9L manifold to Y-pipe flanges are rusted away on both sides, (although the Y-pipe itself looks A-OK), giving me bad and worsening exhaust leaks that enter the vehicle. There is very limited access to these flanges, especially on the passenger side. Can't seem to get at 'em from the top or the bottom. The flange bolts are badly rusted, and the heads won't even take a wrench, never mind turn out. But yet the rusted bolts are still strong enough to hold the remnants of the flanges in place and prevent removal of the Y-pipe. Even if I took off the exhaust manifolds off (which I'd rather not do on a 20 year old motor), I still wouldn't be able to get at the flange bolts. Can't even get a grinder down there.

What is an approach or method to get these rusted out *&#@*()!Y*^$ bolts out and the Y-pipe off??? My intention was to replace the rusted flanges with split flanges. Any help appreciated. Thanks.

CraigK

 

[86XLT]

they are easier to get too from underneath the vehicle...probably a die grinder with a small cutting disc would be your best bet

 

[np24]

I've been through this before. I ended up pulling the engine and replacing both manifolds. all the manifold bolts broke off, so i had to drill and tap all 12 of them.
try getting a tank of mapp gas and a good torch and heat the manifolds and bolts.
use a stud remover, the kinda that looks like a socket with teeth inside.
if you get it hot enough, they'll come out.

 

[injun_ben]

just did the ones on my 94 3.0.......I had the tranny out to replace the clutch....but i ended up jut taking a cutting torch and torching out the old studs.....works fine but you have to be very careful!!!!have a spotter making sure you dont light the rest of the truck on fire, then take a tap and tap out anything that may be lleft in the threads...ididnt even have to....the manifold cast iron melst a a higher temp that the steel in the studs which is why it works

 

[ttfiveohranger]

Anyone else ever use a pipe wrench after grinding off the top of a bolt and soaking with a good penetrating oil(rust eater)? It really has worked miracles for me with rusted shit! if you can get a pipe wrench on it.. It has worked better than anything else for me.

 

[Original_Ranger84]

I just took the y pipe off of mine because i needed to remove the transmission. every day soak it in some PB Blaster like in the morning, when you get back from work and before you go to bed, for about a week. Get a half Inch deep impact socket that is 15mm i think and just one or two really long extensions and break them loose they sould just come off. also try heating the nut up right befor you take it off.