"Steve" <junk@therivets.net> wrote in message
news:OoednZwcEKQywXvenZ2dnUVZ_tWdnZ2d@giganews.com ...
> The front of the cat has a flexable connections with bolts and springs. No
> problem here. The back end of the cat has three threaded studs/bolts
> coming out of the flange. I'm hoping to reuse the cat but I cannot get
> these three bolts out of the cat.. I had to cut the rusted nuts off to
> disassemble and I need to be able to bolt this end of the cat onto the new
> pipe I'm replacing. Looks like I'm going to have to grind the flange flush
> on both sides and drill the holes out to accept three new bolts????
>
> I've never seen perminant bolts like this?? I've seen a fixed nut on one
> flange but not the bolt.????
>
> When I look up new Catalytic converters it looks like there are holes
> there not threaded studs???
>
> Could these bolts be badlt rusted in place? I wacked it pretty hard and
> have just about cut one of the "heads" off (they look like a "t" head not
> a nut shape) and the shaft of the bolt wont budge... Like its part of the
> flange..
>
>
> Is this unusual????
>
>
> Thanks
>
> Steve
>
If they are nuts, I have a trick that often helps me. If they are bolts it
won't help.

Clamp a pair of vise-grips as hard as you can on a pair of the flats of a
nut, then spray penetrant on the end of the stud. (As Elle says, WD-40
really isn't the best choice.) Let it sit for a minute or two and move the
vise grips to another pair of flats if they are accessible and repeat. Do
that to all the sides of all the nuts you can reach.

Clamping the vise-grips on one axis forces the threads to bottom out and
opens up teeny gaps at right angles for the penetrant to get in, and also
upsets the bond they have been making over the years. I don't know how much
it reduces breakaway torque but it has freed pretty much every nut I've used
the technique on.

Mike