Best way to loosen tight hex bolts

Also a good trick to remove socket head allen bolts when they get stripped out is to use a dab of valve grinding paste on the allen tool to help improve friction. Also works great on stripped screw heads. The paste is available at pretty much all auto part stores for a few dollars a container. I have broken many screw driver bits off in what was a stripped screw. I love my air tools >:-}

Archiddeon wrote: In terms of anti-sieze compound ... can anyone recommend a good brand to use? Also, which bolts should it be applied to and which should have locking compound on them? I know in the service manual it specifically states that some should have locking compound ... all others anti-sieze?

Thanks

Your service manual should tell you what to use on different bolts. In my personal experience, you don't ever want to forget some of the blue loctite on your engine sprocket cover. I made the mistake of not using it once...all four bolts fell out and I lost the ability to use the clutch. I got extremely lucky, and rigged it up somehow (don't remember how anymore), so I didn't have to come back with my truck for the bike. I never forgot the blue stuff on those bolts again!

.

Archiddeon wrote: I'm trying to get the cap off the side of my GPZ 550 engine to hand turn the crank and see how the pistons feel, but the Allen-type hex bolts are proving stubborn. Got them hosed down with some PB Blaster, but wondering what the best approach is to loosen them while minimising the risk of stripping/rounding the inside of the heads?

I suppose from worst to best would be Allen key - hex socket - impact wrench with impact hex socket? How would normal hex sockets versus the rounded-head ones compare?

Thanks!

I have two air impact guns, a 1/2" and 3/8", and they're cheapo's from Lowes, been using them for years now. Anyway, I've found that for smaller allen cap bolts the 3/8" gun works great with an allen socket set. A set of allen sockets isn't terribly expensive at all, Lowes, Home Depot stuff is adequate, or even Harbor Freight. Even when the bolt head is kinda galled, firm pressure against the fastener with the gun and the impact "shock" of the gun has really never failed me, except one time -- trying to get the allen plug off the left side of my DR650 Suzuki. But that's aluminum. I had to chisel that one out and purchase a new replacement. But for steel fasteners, pneumatics work best.

As for anti-seize, I buy the permatex brand in the bottle with the brush. Lasts a long time too.

For really stubborn bolts of any sort, assuming there's no fire hazard, heating them a bit almost always helps. Aluminum and steel have different expansion rates when heated and plus, considering some of these really stubborn fasteners may have thread lock on them, it tends to soften that material a bit.

I m not sure that this is possible,considering the size of the allen head.

In the past, while working on the brake cylinders on an old truck, I heated up the head of the bolt with a propane torch (or Map gas) till it's "good n hot". Then I took and ice cube and melted it on the head of the bolt, being careful to cool off only the bolt head and not the surrounding area. After 30 seconds of melting, I loosened the bolt.

Never failed.