Please Help!! Stuck Cylinder Head Bolt!!!

[Guest]

I'm doing a valve adjustment and obviously I had to remove the cylinder head cover. A couple of the bolts were frozen and i tried to be gentle and use WD40 to loosen them but eventually they broke.

I then soaked the Bolts in WD40 for a couple days and tried to file the tops of the bolts flat and turn them out with vice grips but again they would not budge.

so I decided i'd get out the dremel, snip the tops to be flush with the cylinder head and drill out the centers to try and use a bolt extractor bit.

But Here's the problem, The bolts drill in a tiny bit and then once the depth got just below the cylinder head itself the drill stopped working. it's as though the metal from the has hardened and become impervious to the drill bits(yes i tried 3).

there has to be something I'm missing? I suppose I'll have to go looking for specific kind of bit, does anyone know what kind or have any ideas as to how to get these bolts out of the cylinder head??

[cowboyup3371]

First off WD40 is not a penetrant so it's not going to help loosen them up. You'll want some PB Blaster as well try to weld the top bolt back on. It will help heat up the slot and back it out.

[Nessism]

Your bit is dull.

It saddens me to read about people breaking off bolts when it's avoidable most of the time. You need to use real penetrating lubricant, not WD-40. Plus, you need heat on the screw. Get a propane torch and heat the bolt good and hot, red hot even. Heat and spray, do it a couple of different times.

If there is still a nub to grap try heat and the vice grips again. If you must drill the bolt out, do NOT use a screw extractor. Get some LH drill bits and work slowly, increasing the bit size a step at a time. Typically the nub will spin right out after you get most of it drilled out.

Good luck and please check the archives for tons of useful info like this. Read first, then wrench.

[Steve]

I'm doing a valve adjustment and obviously I had to remove the cylinder head.

Terminology adjustment here, if you don't mind.

You did NOT have to remove the head.

At least ... when I was there, you had only removed the cylinder head COVER.

You get your new shims yet?

.

[JEEPRUSTY]

I'm doing a valve adjustment and obviously I had to remove the cylinder head. A couple of the bolts were frozen and i tried to be gentle and use WD40 to loosen them but eventually they broke.

I then soaked the Bolts in WD40 for a couple days and tried to file the tops of the bolts flat and turn them out with vice grips but again they would not budge.

so I decided i'd get out the dremel, snip the tops to be flush with the cylinder head and drill out the centers to try and use a bolt extractor bit.

But Here's the problem, The bolts drill in a tiny bit and then once the depth got just below the cylinder head itself the drill stopped working. it's as though the metal from the has hardened and become impervious to the drill bits(yes i tried 3).

there has to be something I'm missing? I suppose I'll have to go looking for specific kind of bit, does anyone know what kind or have any ideas as to how to get these bolts out of the cylinder head??

Can you show us a picture please?
I cannot see how a bolt would snap on removal from the soft metal cam caps beneath the valve-train cover.

[gmoore]

sorry, yeah I meant the cylinder head cover. no shims yet.

there is no more head/nub left so drilling is a must and thanks for the bolt extractor tip, i'll get a LH drill bit and some PB blaster tomorrow.

I imagine any hardware store should have LH drill bits?

[Steve]

I imagine any hardware store should have LH drill bits?

A GOOD store will, not sure if I would expect to find them in a "big-box" store, though.

Might have to see if your local ACE hardware has them. If not, you can order them.

.

[laverda1200]

drill bits come in various hardness/strength, as well as right twist/left twist.

any kind of dull drill bit, no matter what it is made of, won't work very well.

Cobalt drill bits are what you want for a tough job, strong bit, holds its edges well, .

screw extractors or tapered shank extractors are kind of scary to work with. They are really hard, and a bit brittle, so if you snap one off in the broken off bolt you are trying to remove, you have made your problem a lot worse, as they are too hard to drill out.

as mentioned in earlier posts, you need a decent penetrant (NOT WD 40, useless **** that it is), probabaly one of the best out there is KROIL http://www.kanolabs.com/, but PB Blaster is OK and much easier to find to buy. Oddly enough, a really effective home made penetrant that works really well is a mix of acetone and transmission fluid, mixed half and half.

Heat is also essential, but careful with a propane torch on an aluminum head.

if you have a Dremel or similar with a small cutting disc, you may be able to cut a decent slot in the broken bolt head and use a straight screwdriver once you have soaked in penetrant and heated.

if all else fails, a lot of decent machine shops will have a "spark erosion" machine and can remove the broken bolt stub for a reasonable fee, Or, if you totaly bugger the htreads of the hole, no problem, lots of thread repair products out there. Time Sert is what I use, really good product http://www.timesert.com/

finally, whenever you remove a steel bolt from an aluminum motor, coat the threads with some sort of antiseize thread coating when you put the bolt back in, the antiseize is cheap insurance against the bolt seizing recurring, it stops the reaction between the steel and the aluminum. A big jar of antiseize coating is cheap and will last a long time around the garage, I use it on every fastener on every bike that passes through my garage. http://www.canadiantire.ca/AST/brows.../AntiSeize.jsp

Paul

[Hoosier Daddy]

I thought I would try and help you out, but I see you are already in good hands, heed their advise. So that being said, all I have to add is...
The only way to get good at removing broken bolts is to break way too many!
Good luck to you!

[Nessism]

I thought I would try and help you out, but I see you are already in good hands, heed their advise. So that being said, all I have to add is...
The only way to get good at removing broken bolts is to break way too many!
Good luck to you!

You don't want to "get good" at removing broken bolts, you want to "get good" at avoiding broken bolts.

We get a lot of broken exhaust header bolt threads around here and most of the time these broken bolts can be avoided by using proper extraction techniques. Unfortunately, most people don't start the thread until after they have broken the bolts and that obviously is too late.

[gmoore]

Live and learn I guess, I'll definitely be more patient in the future because this is a total PIA!! haha.

I'm going to have to find a right angle drill as well since one of the broken bolts is directly under the frame neck, total bullcrap!! haha

All I can do is chuckle and be patient.

[Hoosier Daddy]

Well of course it is!!!

[laverda1200]

Live and learn I guess, I'll definitely be more patient in the future because this is a total PIA!! haha.

I'm going to have to find a right angle drill as well since one of the broken bolts is directly under the frame neck, total bullcrap!! haha

All I can do is chuckle and be patient.

well, it took me less than an hour and a half from start to finish to remove the motor from my 81 GS 750 EX project...... will probably take me about two, two and half hours max to stick in back in, reconnect everything, dial in the freshly rebuilt carbs, etc.... so three and a half hours for you to be able to have full easy access to the broken off bolt stubs, I'll bet you spend way more time than that trying to deal with your access issues to the broken bolts, personally I would just yank the motor, seriously.

Paul