Cap Head Bolt Removal

[Rory's Dad]

Am halfway through replacing the rear discs and pads on the rear of my Westy - Sierra calipers. What I've done thus far is undo the two cap head bolts that fix the caliper onto the Westfield Alloy uprights, remove caliper, replace pads, screw in the piston, replace disc and put it all back together again - but I've bu99ered the last bolt trying to undo it. They are mighty stiff having been threadlocked in. Anyway the hexagon headed hole now a bit round and won't hold the bit.

What do I do now?? Try and drill it out??

Rory's Dad

[s2rrr]

Martin,

You may get an easyout to catch on the hex sides but otherwise its a drill out job. Drill off the head then use a smaller easyout on the stud thats left or you may end up drilling that out and retapping it. Are they recessed or can you get a bit of brute force on them like a pair of pipe wrenches, not molegrips or gland pliers. I am a bit confused as you say you've removed the caliper which means the bolts have been out ??. This is one of the two caliper bolts we are talking about, is it ?.

Bob

[Rory's Dad]

Sorry Bob - yes i managed the first caliper OK all done and dusted - it's the second that gone wrong. I've got the first (upper) bolt out OK but it's the lower one that's bu99ered. I'll go and have another look shortly - watching bikes at Cadwell ATM!

Rory's Dad

[Dave Eastwood (Gadgetman) - Club Chairman]

Try tapping a Torx headed bit into the cap head, use one that slightly oversize and you can get the splines to "bite" into the bolts.

I'd really treat Easy outs as last resorts, they're notorious for breaking off in the bolt, trouble is they're so hard you often can't drill them very successfully.

Other thing I've done successfully with deep cap heads before now is to drill sideways through the bolt head so that you can get a tommy bar through. TBH, these days though, I just weld a bit of bar to it. The heat shock also helps to free it off.

You can also get freezing sprays, which I've never tried, but I believe can be quite effective.

[Steve (stevel)]

Martin you could try an Irwin bolt remover, I have a set, never tried them on a cap head but they should still grip, they have got me out of a few fixes, let me know I could bring them with me on Wednesday.

Steve

[Doug Dastardly]

Martin you could try an Irwin bolt remover, I have a set, never tried them on a cap head but they should still grip, they have got me out of a few fixes, let me know I could bring them with me on Wednesday.

Steve

Never seen them before!

Mentally filed for future use

[pete g]

try stilsons on the head. or cut the head off and the caliper may have enough room to get off with pads removed.then use stilsons on the rest of bolt remaining.

or you could try either welding you allen key to the bolt or another bolt to it. the heat from the welding normally helps release them

[the stoat]

Try tapping a Torx headed bit into the cap head, use one that slightly oversize and you can get the splines to "bite" into the bolts.

This is what I normally do.

[Rory's Dad]

Well I've given up and have booked the Westy in to John Hoyle for him to fix and for its MOT.

Thanks for all your advice. Gadgetman/the Stoat - the next size Torx would not 'tap' in and it would respond either when I tried to biff it in with a large hammer. Stevel - thanks for the offer - I'll see you tomorrow at the Bay Horse! I expect John will try the welding approach but that's beyond my ken

Rory's Dad

[John Loudon - Sponsorship Liaison]

I'm with Pete G's suggestions. In the past I have also cut a slot across the head with a hacksaw and used a screw driver in it and also used a collet type stud extractor on the outside of the bolt head

[Rory's Dad]

All sorted - thanks to Mr Hoyle.

Rory's Dad

[BigRuss]

Did you ask how he did it?

[Rory's Dad]

Not yet - I'll ask him tomorrow at our monthly meet (if I remember!)

Rory's Dad

[StuartMackay]

Or weld a larger hex nut on it also works

[Dave Eastwood (Gadgetman) - Club Chairman]

Or weld a larger hex nut on it also works

Never thought of that, like it!