98 silverado exhaust woes
 

Has anyone had issues trying to remove the flanges from the manifolds on a 5.7 ?? I used the torch to warm up the nuts , they came off fine , but the flange wont move .. what do I do next ?? http://i306.photobucket.com/albums/n...ps85862ac7.jpg http://i306.photobucket.com/albums/n...ps22759fc9.jpg http://i306.photobucket.com/albums/n...ps164c953c.jpg

Problem solved
 

Re: 98 silverado exhaust woes
 

Putting headers on wont fix the problem with the y pipe.



I would keep cutting away at the flanges, a little at a time, trying not to disturb the manifolds too much.

If you are re using the y pipe, they make repair flanges. If you are replacing it, Your new one will come with them.

If you are re using your manifolds, Clean up the threads with a chaser or a die.

Re: 98 silverado exhaust woes
 

tap on the flanges with a small hammer. you can use a screw driver to pry a little. they are probably stuck on the gaskets. you have the worst part done. I broke all six of the studs when I did the trans in my old truck. that was not fun. little tip when you put it back together load the studs and nuts with anti seize. you with thank yourself later if you ever have to take the exhaust down latter.

Re: 98 silverado exhaust woes
 

Yeah I thought when i got the nuts off , I was golden .. But I normally work on older stuff , meaning my 63 ... For years ,stamped steel flanges worked just fine , I suspect some engineer that never worked on a truck came up with those flanges ....Looks to me like the space between the stud and the flange was so small rust has built up in the space ...more heat ,more hammer...

Re: 98 silverado exhaust woes
 

Mine were stuck but I don't think they were as bad as yours. I disconnected the cat and sprayed PBbuster on the studs. Then let it set overnight. Then I used a 3lb dead blow 2 pry bars and a small ball pen. That didnt do much but knock dirt all in my face. What ended up working was a size 10 1/2 shoe, some cussing and a lot of arm power. I man handle it wiggling it around by the end where the cat goes and kept kicking the snot out of it. Finally it broke free.
You are right, it gets rusty around the holes and thats what holds it. Then I had a bright idea of changing the studs while I had it apart. That was a no go. Ended up just chasing the threads and using new springs and nuts.

Re: 98 silverado exhaust woes
 

I guess I should start a build thread since I have owned the truck since Monday ..... This truck was for sale for 4300 one week before ,then it dropped to 1500 with an engine noise.... The roller lifter wont come out of the block so I know it needs a camshaft ,so I figured I would just freshen the engine if I was going to tear it down that far ... I just maybe having second thoughts... but since I work in a machine shop and I may keep the truck for a while ,well you know ............ so I will keep driving the 63 in the mean time....

Re: 98 silverado exhaust woes
 

UPDATE .. I did soak the flanges with pb , then used the air hammer with a chisel bit on it and they did come off.. the one I broke was also a easy fix , midas at the end of the street had a 3 bolt steel flange tha was split in the middle and heald together with 2 5/16 bolts ,worked like a breeze..

I had a shortblock and a set of vortec heads that I threw together and did a quick break in on my buddys dyno to confirm it had no leaks etc (dyno'ed with a carb) ,it was nice to get everything hooked up while standing in front of the engine as opposed to pulling the intake while the red was in .. I think If I do any work like that again I will remove the stuff off the front and stand instead of lay over the engine...