Rear caliper mounting bolts seized

[Colts]

Hello the collective...

Whilst attempting to check the rear pads on my 1150gs I have discovered the caliper mounting bolts have seized solid. I can see that there is a fair amount of life left in them but I would still like to take them out for a proper check.

I have tried more leverage,
Hammer,
Popping into a local garage who whilst very helpful were not able to sort it today.....
WD40,

all to no avail - any of you fettlers out there got any tips?

Frustrated with sore fingers...


Colts

 

[sockpuppet]

1/2" Breaker bar will shift it or snap the bolt which ever comes first.

Failing that some proper penetrating fluid not WD40 as it's shit.

 

[Cook1e]

Warm it up. Oxy torch is best as you can focus the heat better, but a plumbers blowlamp will do.

The key thing is differential expansion between the steel bolt and alloy thread breaks the corrosion (or Loctite...). Use Copperslip (or BLUE Loctite) on reassembly.

 

[davegs]

Heat

How on earth can you use knaked flames i.e. blowlamps or oxy torch on a bike! this thing must be fixed to the bike still. If you need more heat than a hot air gun borrow an arc welder and put the eath clamp on the caliper and a rod pushed hard against the bolt. Give it a shot of a high current for a minute or two and switch it off before removing the riod so you do nopt get an arc (buggering up the bolt) let it cool down and it should come undone.
Disconnect battery and earthing lead this has been done many times on exhaust studs so try it, but DON'T use a knaked flame.
Dave GS

 

[ianboydsnr]

Warm it up. Oxy torch is best as you can focus the heat better, but a plumbers blowlamp will do.

The key thing is differential expansion between the steel bolt and alloy thread breaks the corrosion (or Loctite...). Use Copperslip (or BLUE Loctite) on reassembly.

he's right

How on earth can you use knaked flames i.e. blowlamps or oxy torch on a bike! this thing must be fixed to the bike still. If you need more heat than a hot air gun borrow an arc welder and put the eath clamp on the caliper and a rod pushed hard against the bolt. Give it a shot of a high current for a minute or two and switch it off before removing the riod so you do nopt get an arc (buggering up the bolt) let it cool down and it should come undone.
Disconnect battery and earthing lead this has been done many times on exhaust studs so try it, but DON'T use a knaked flame.
Dave GS

He's definatly wrong

 

[Colts]

numpty question and asking for trouble but......

Do i direct the heat on to the bolt, the fitting or both??

Colts

 

[ianboydsnr]

numpty question and asking for trouble but......

Do i direct the heat on to the bolt, the fitting or both??

Colts

the bolt

 

[Cook1e]

How on earth can you use knaked flames i.e. blowlamps or oxy torch on a bike!

Done that many times without problems.

If you need more heat than a hot air gun borrow an arc welder and put the eath clamp on the caliper and a rod pushed hard against the bolt. Give it a shot of a high current for a minute or two and switch it off before removing the riod so you do nopt get an arc (buggering up the bolt) let it cool down and it should come undone.
Disconnect battery and earthing lead this has been done many times on exhaust studs so try it, but DON'T use a knaked flame.
Dave GS

Wouldn't recommend this, though I guess it could work. It could also weld the bolt to the thread and fry your ECU, battery disconnected or not.

If DaveGS's worry is about burning painted/plastic bits, cover them in wet rag before you go in with the flame, but I don't often find it necessary.

Here are the "Long" version of the instructions...

Plenty of penetrating oil from all sides, leave to soak, heat the bolt/fitting (doesn't really matter which, you're wanting them both to expand) to about 200-300 C (sizzles hard when you spit on it), lean on the breaker bar -try shocking it rather than a steady pull (not too hard mind, you really DON'T want to shear the bolt), if it doesn't move use more penetrating oil (whilst it's still hot, helps it penetrate) and repeat. It'll usually make a kind of tortured shrieking noise when it starts to move.

Don't even bother if a few drops of penetrating oil burns - it soon goes out (DON'T set fire to big puddles of it though!), but it is a sensible precaution to have a fire extinguisher (or a bucket of water or a hosepipe etc.), whether using a flame or a welder.

Good luck!