Sooo, I was try'na drop the exhaust so I can get down and dirty with the oil pan and snapped both of th "y" pipe bolts (the ones that the bolts don't go all the way through) one on each side and now I'm standing here with a confused look on my face and don't know where to start(extracting). I think it sounds kinda cool:Brow: but my wife seems to think it sounds like something else. What sorts of tools should i use and what is the easiest way to get these broken bolts out?
Have you considered a short drive to the muffler shop and force them to do it? I hate exhaust work. The iron fitting suck to begin with, and then let them absorb carbon for how many years and you just have a whole bunch of ugly. I'm a machinist and own my own shop so tooling is easier for me to acquire, but I would start with a center punch and then center drill to get a nice small hole in the center of that broken ugly. Then slowly open up the diameter until you get close to the minor diameter of the threads. A 1/4-20 bolt has a thru hole size of .200, so a little over 3/16. 5/16-18 has a 1/4" thru hole size and a 3/8-16 thread has 5/16 thru hole. Try not to drill any bigger than those sizes thru the bolt. Bathe the beast in penetrant, not that it will really help much, but it feels right that you are hosing goo on there. Then start the easy out. Some of the best systems I have seen are the ones that actually use a Left hand cutting drill. That way it either drills the hole or backs out the bolt. Similar to these. http://www1.mscdirect.com/cgi/NNSRI...re=ItemDetail-_-ResultListing-_-SearchResults Oh, and swear alot. Well, that seems to be my method.
Just make sure you save yourself some aggrivation and use a really good drill bit. I've been using BOSCH Titanium bits lately and they're great, but there may be better. And make sure you put a dab of oil on that bit and don't overheat it.
Couple options depending what tools you have. If there is enough of the stud left to grab with vise grips and you have access to an oxy/acetylene torch, heat the manifold up red hot right around the stud and they will come right out though I'm guessing if you had a torch you wouldn't be in the predicament to begin with. If no acetylene torch, use an abrasive cut-off wheel and cut any of the stud (if sticking out)off flush so there is a nice flat surface to help get a dead center punch mark to start the drill. This is very important. The cast manifold is softer than the stud so if the drill is off-center and starts into the cast, it will take the path of least resistance and you will be SOL. Start with a 1/4" bit then work up as houndog suggested. It is doubtful you'll get it to come loose with a screw extractor without heating it red but you can try. Use a Mapp gas torch and get it as hot as you can. Just don't break the screw extractor off. :shock: If that doesn't work continue drilling and end with a drill the size which is suggested as the tap drill for the stud size it is. If you get really lucky drilling perfectly parallel, you can "carefully" run a tap in to cleanout the threads. Worst case you can drill and tap up to the next size stud. I've had to do that on a few occasions. This job is way easier if the manifold is off.....but that process in itself could lead to more broken bolts. An oxy/acetylene torch is my best friend when working with exhaust manifold bolts. Good Luck
When I took my engine apart for rebuild I just let the brought the exaust manifold in to a local shop to have the broken UGULY drilled out and a threaded plug put in. It is working great, but was $$$ou:
I'm a little embarrassed to say but I drilled mine straight though and used 3/8 x 16 threaded rod and 3 nuts to make my own. No leaks.I don't plan on keeping the manifolds after the engine build so I figured what the heck!
No need to be embarrassed, I've drilled through as well in desperation on old beaters I used to drive. It works but ain't the purdiest. Thats one of those repairs when I say, Oh, the guy who had the car before me must have did that.
I didn't even do that,i used a caddy 3/8 beam clamp, slung the end over the tab ran the bolt into it and tightened the nut down,15000 miles later its still there!
from all my experiance working on diesels in tractors and semis I have found the best way is to drill the center out, then I weld the hole up(the heat tends to break the rust bond) weld untill you have a nub above the flat surface, then weld a nut onto the nub. let it cool and back the broken stud out.
My exerience is with a head or two with broke off manifold bolts. Granted they are off the car but I used a box of nuts, my little wire feed welder and an impact. Works way beeter than drilling and ezouts for me. I am going to try thr drill a hole and weld it up next time as it sounds good and with as many nuts as I weld on one hole and weld up wont add much to the project.
