Removing rusted bolts

[Fordman999]

So I have decided to change the catalyitic converter myself. After looking at it my only concern is that the bolts and nuts on the flanges of the exhaust and cat intakes are going to break from so much rust. My car is 2003. I guess I can use vice grips to spin it off but does anyone have suggestions on preventing this from happening? I began to spray and "pretreat" the bolts with WD40 days ahead in hopes it soaks the threads and breaks off easily.

If not should I be afraid if the bolts break? Is there a method to remove a broken bolt on a converter gasket flange? The repair is going to be done in my building parking garage outside.

 

[jayyzar]

Your on the right path! Lots of penetrating oil. I have had lots of luck with CRC freeze off and ATF. at different times. A 50/50 mix and it breaks everything lose because its such a thin oil.
Freeze off or a map gas torch help out a lot. just be careful for obvious reasons. Because the two metals are different thickness they will expand or contract at different rates to break it loose.
When ever something is rusted on i use an impact if there is space but you can do it with hand tools as well. Regardless it can still snap. Be patient and be prepared. If you have access to an impact use it even if its a ¼ battery one. it applies the force more even (I've been told) but i know it works. Just be ready to get new bolts if worst case happens. There is no guarantee the bolts will behave

 

[LMHmedchem]

A cheep set of bolt extractor sockets can help allot, even if then nut is completely rounded off. You can usually get a set for $20 or so, but the deep extractor sockets are more if that is what you need.

Leverage is your friend, so have a nice long extender pipe and someone to help out. It's hard to hold the socket in place and get good purchase on the pipe yourself. Most muffler shops just torch everything off to save time. It is likely that at least some of the hardware will break before it comes loose. With that kind of thing, I would want to replace it anyway instead of trying to re-use something that rusted.

LMHmedchem

 

[JoshMcMadMac]

Kroil...I have not find a penetrating oil that even comes close. Use that, and heat if you have to.

 

[Highflow50]

Did you get a direct fit factory catalytic converter or a universal fit unit? The simplest way to do the job is a Sawzall and exhaust clamps. Exhaust bolts are very difficult to remove due to constant heating and cooling cycles.

 

[TechGuru]

Did you get a direct fit factory catalytic converter or a universal fit unit? The simplest way to do the job is a Sawzall and exhaust clamps. Exhaust bolts are very difficult to remove due to constant heating and cooling cycles.

That's also the improper way and setting yourself up to have leaks.

 

[mbrando1994]

I know I may get some slack for this but I'd avoid using vice grips. All they will do is apply more force inwards on the nut. If you're using them to hold the bolt head, different story.

+1 on the bolt extractor set. I got one a year ago at harbor freight and has worked perfect since - other than me losing one of the sockets.

Use lots of penetrating oil, avoid WD-40, get PB blaster or another automotive product. Spray the bolts every day for about a week before you do your project. Avoid overspray as you are working on the exhaust which gets very hot.

When you're finally ready to start I recommend using the extractor socket straight away. Chances are the bolts are rusted and will chip away no matter what you do with a standard 6-point socket. Try heating them up with a propane torch but be mindful of fuel lines and other flammable materials throughout the undercarriage.

If all that doesn't work find someone who has impact tools or just resort to cutting the bolt apart. You never know when a bolt will break and that's why many part manufacturers include new bolts with their parts (Ford usually recommends replacement anyway)

Best of luck to you, this is yet another one of those PITA jobs to do but once done you'll feel lots better!

If you do decide to order new bolts, be sure to order new bolts for the cross member you need to remove in order to remove the cat assembly. Fords are notorious for the frame bolts breaking off or being extremely difficult to remove. It's always better to come prepared!

 

[TechGuru]

Be sure to spray both the nut and the stud at the manifold side. I'd personally try a impact first, got two places for it to break loose (nut or stud in the manifold). Might get lucky and have the whole stud come out. Always replace with new!

 

[Highflow50]

When I did my headers a couple of months ago the exhaust manifold bolts were completely rusted together. I soaked them with Kroll and still no go. I did this in a heated garage with a large selection of air tools. I had to finally break down and get some cobalt drill bits to get one out. For the rest of them I used a cutoff wheel.

My question for Fordman999 is are you replacing all 3 cats or just one?

 

[Fordman999]

Thanks mbrando1994 your advice is the best and I will do what you said. I already purchased brand new bolts I just hope I dont break a thread and have to drill through. uuuuugggghhh that will be hell and the flange bolts to my cat are high up near the engine. I will try my best.

 

[Fordman999]

When I did my headers a couple of months ago the exhaust manifold bolts were completely rusted together. I soaked them with Kroll and still no go. I did this in a heated garage with a large selection of air tools. I had to finally break down and get some cobalt drill bits to get one out. For the rest of them I used a cutoff wheel.

My question for Fordman999 is are you replacing all 3 cats or just one?

I'm replacing all three I'm buying the whole cat system I just need to remove the studs and the spring bolts on the exhaust. I hope it goes smoothly.

 

[Highflow50]

Best of luck seach around and get all new hardware for the installation. Also I would recommend replacing all the oxygen sensors while you are at it.

 

[psi2rd]

I second kroil or lots of heat. Get them orange, they WILL break free

 

[amberanger]

make your own rust=buster

Better that Kroil, just mix 50/50 synthetic transmission fluid and acetone.

Be sure to use a steel container or very good plastic as this stuff works.

 

[clsale1999]

I'm replacing all three I'm buying the whole cat system I just need to remove the studs and the spring bolts on the exhaust. I hope it goes smoothly.

Fordman999, whatever happened with your cat flange bolts. Did they come off with the penetrating oil or did they brake off?

 

[Fordman999]

Fordman999, whatever happened with your cat flange bolts. Did they come off with the penetrating oil or did they brake off?

Hey clsale 1999 sorry didn't get back with this thread I ended up being able to remove the bolts except 1 sheared off and broke and I just didn't bother trying to remove it off. I sprayed with plenty of penetrating oil the day before. The one that sheared off I tried removing it on the spot which was a stupid move. I immediately stopped and sprayed all bolts and let it soak for a day. I also was able to find replacement bolts at Fastenal. But I didn't have to use them so I returned them.

 

[clsale1999]

Thanks Fordman999, Appreciate the tip on replacement bolts at Fastenal.