I've used Kroil for years. Problem is on exhaust manifolds and things like that, its hard to get the Kroil to the actual threads so it can do any good.
Originally Posted by Close Work
As said above, if you can get a good swing with a hammer, hitting the head of the bolt fairly hard can help jar the threads to help it come out easier.
if some of the bolt heads round off, just cut/grind the head off and pull the manifold off, then use a stud tool/socket to take the studs out. I never was stumped with Cat nuts + bolts. Another vote for KROIL! Steve
regarding the stud... How about, if possible, with a die grinder with an about 2 inch right angle disc? I did two today and was supprised how close I could come to the stud, grind and not do any real damage. Now, a question to all: why not replace all manifold stud nuts with brass nuts, even if we have to drill and thread ourselves? The Enghish had this on most. if not all, their four cylinder cars. Any ideas? Wayne.
I have pulled hundreds of the OP's exhaust nuts and studs out of Cat motors.
Lots of talking, but they come right out.
Just put a 3/8th impact on them. If they don't come loose, then worry about it... Go to 1/2....
Lube/Kroil works fine on the studs, but will not get into the threads well on 3208 manifold bolts. Sure slather some on, but don't worry about them...
They will come out...
Most British cars were not turbocharged, much higher heat and pressure with a turbo... Brass nuts MIGHT hold up, but the studs cook, and would take the brass threads out on removal... I have only worked on RR and MG engines.
Get off you ass and pull the manifold. It is just a thing, if a bolt breaks, drill it out and get on with life. Not even a machinist worthy thread...
Far better things to ponder, than 30 year old rusty manifold bolts..
Abarnsley, we have a manifold coming and should have it figured out next week. I agree that the penetrating lube just won't do anything for us on this. This engine is not a turbo engine though so that might help us. It is good to hear they are grade 8s.
Oh yes, the ONLY semi modern, Cat piece of equipment up at mine, without a turbo.. 40's stuff does not count..
The 225 up there was rolled 2 years ago.... Took out one main hydraulic pump input shaft, all the engine house tin, and exhaust system. I was not there for replacement of exhaust... If they had a problem with a bolt, I would have been called.. I did get to put the new pump input shaft in...
They had no trouble sourcing used parts. Beat tin back into shape, and back to work...
On my IH I cut the bolt heads off with an abrasive cutoff wheel (I keep one on a 4" right angle grinder).
Then I turned the studs out with a "stud remover" on 1/2" breaker bar.
A little pounding on the heads, penetrating oil, work it back & forth if necessary. I ended up having to drill out a couple to the thread minor diameter & chasing the threads, but most turned right out.
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All 8 bolts going into the manifold were absolute cake. 15min, done. One bolt has some rolled over threads so I might see if I can get a chase in there before going back on. Problem now if the 4 bolt collector. Thing has been off before and some idiots used some junk bolts and they are half eroded away. no chance of just breaking them off. I have ti figure out a way to cut them. I would try whacking them but everything is cast and I could end up buying another, less popular part if not careful. Problem is I just cannot get to these bolts. 2 of them I can, the other 2 will likely take the rest of the day. Might be a job for a dremel or something.
Manifold already has some HUGE welds on it from breaking in the same spot. Not sure if the exhaust has been smacked twice or what. Good times over here today...
And also about the rest of the exhaust manifold bolt problems..
For tough to get to bolts, a carbide 1/4 in burr in an air grinder, will work about 20X faster than a dremal.. The micro chips will get you though...
I end up drilling, grinding, torching heads off.. The manifold with its attached/connected rust monsters, takes the most time... Unbolting from engine is easy..
In a pinch ,you can weld up large pipe elbows etc, to cobble rest of system together. It is just an exhaust redirector anyway Anywhere but into cab or air cleaner is good.
Don't worry about drilling the bolts out. They're not grade 8 studs. The outside is hardend but the insides are soft. Cat exhaust studs are notorious for breaking off. They make a nifty little drilling jig with drill bushings to bolt to the head for drilling them out. Works like a charm. Good Luck.
Well, here is where we got today. FFFFFFF!! 4 bolt collector flange is my slut tomorrow. I was able to weasel in a cut off wheel to all 4 bolts. On 3, I took off the nut side, 1 I took off the bolt head. NONE of them will move AT ALL. WD-what.... Right. That is a joke. I do not have any Kroil but I have my doubts on it working here. I used a punch to try and free them but the receiving end is also cast iron and when I break that, I buy myself another couple days minimum of either trying to find parts or fabbing something up.
I am ALL ears for a way to pull the deal off. I can only get at 2 of them with a punch or drill, other 2 are tight. I would beat this piss out of it and REALLY want to but I am old enough now to know better.
As well, after seeing that this is the 2nd time for a broken manifold, I figured I might check some engine mounts. Front engine side has 2 main bolts. 1 missing, the other loose. It was not a real good idea for CAT to solid mount everything. I have no idea if the motor torque broke the manifold or not but couldn't help.
Originally Posted by viper
I have very little patience for almost anything. This type of ordeal is the king of patience trying bastards. Someone suggested using brass nuts on the studs IF you ever get the old ones off. No. 316 SS nuts and bolts. Lots and lots of never seize also, of course.
Again, manifold was completely broke in two. All manifold bolt have been removed and majority of manifold gone'dy. there is a stub and the 4 bolt flange left bolted to the existing exhaust that presents the issue. I noticed that before we started but hoped knocking the heads off the bolts would get them coming out. No-go. Probably go back with 316 stainless. I have worked on many boats with cast exhaust and never fought with this BS but they are not subject to mother nature.
The best way to remove broken studs from a head is welding. First you have to make shure that the stud are not stainless steel. Cat diduse them for a few years. If they arent stainles then the ones that are above the surface of the head clean with a grinder and weld a nut to them. Let them cool and the work them with a end wrench. If they are below the surface of the head clean them with a carbide burr. Then weld a washer with about a 3/8 hole then weld a nut to the washer. If you are careful the weld will not stick to the cast iron.
Again, the bolts (not studs) in the head are a done deal. the issue has turned to the collector bolts which seemed simple at the time. They looked obviously screwed so i did not waste much time before I started cutting. these are bolts with a nut on the back. Simply pinching a 4 bolt flange. Seems pretty simple but after cutting the heads off, the bolts (not threaded in) are still stuck in the flange. Should take very little effort to knock them through but that ain't workin. Couple that with piping that is 30yo cast iron, we need to be OH so careful here.
very simple.heat it and pour some water on the bolts.or drill them out.i find the carbide burr (ball type) works very well,i used a cordless drill on a 5/16" hard bolt one time and it was a real profanity storm.if a drill bit cuts ,go with it.if you drill most of the bolt out,it should relieve the pressure and fall apart.
As was stated heating those bolts hot as hell and then getting after them with anything you can to force them out. Red damn hot on the bolt and then hit it.
Do not cool those bolts with water if you think you might have to drill or cut them. They will become so hard you will be screaming at them for hours.
Get them ""HOT"", get after it with whatever you can to get them to move. Of coarse that's if you can't get to them to just torch them out of there.
Well, today we went in with heat and determination. The 4 bolt collector was decided to be a lost cause while in the machine so we moved further down line in the system and were able to successfully unbolt the other side of the Y pipe and removed the entire Y pipe and muffler system. that allowed us free access to the troublesome collector. It was decided that we made the right call because after even cutting off the already junk manifold side flange, the bolts were NOT coming out, period. They are actually still stuck in the Y pipe side that we still need so we cut then off and will have to drill the last 1/2" of them out of the flange. They are GONE but not enough that they would pop out. I know after seeing all of that, no amount of smacking, heating, or lube would have helped. Primary reason right here to NOT skimp on bolts for systems like this. I also think some of the issue here is that the bolt diameters were too close to the flange hole diam so I plan to drill them a touch bigger allowing the bolts to float in the flange holes a bit. that should allow them to come out later even if the heads break off.
316 nuts AND bolts? Might as well weld them.
Originally Posted by jdj
No SS Nuts AND bolts.. Either one or the other... At least different types of SS ..
That machine will not last long enough for exhaust bolts to be a problem again...
Rest of exhaust will be rotted to point of needing total replacement..