Rear brake caliper [allen bolts froze up]

Got a 79 ltd kz 1000, Been sittin a while, anyway I need to get the two allen bolts out of the rear brake caliper. I was going to use a low grade propane torch, bernzomatic, heat up the bolts to brake the rust bond, but wondering if it might damage the aluminum housing, any ideas?

Tried this? kzrider.com/index.php?option=com_kunena&...w&catid=21&id=347828

Frozen bolts seem to be an ongoing prob when it comes to motorbikes I’ve noticed, so I thought I would share some experience I have gained regarding frozen bolts from my job, I work in the automotive industry reconditioning/rebuilding (power steering technician) and this is a problem also hence the technique I have acquired.

I believe the problem lies when a steel bolt is used to affix the item to an alloy housing for e.g fork tube bolts, head studs etc…. 2 things, one the steel thread cuts into the alloy and 2, there is a chemistry process called galvanic corrosion and occurs when 2 dissimilar metals (steel and alloy etc) are used.
(if I am wrong please someone let me know, I don’t like to go through life misinformed :blink: )

Anyway, to remove the bolts I use a suitable flat drift/punch that is as large as possible but does not go over the edges (still need to put the socket etc on) of the bolt head or one that fits “IN” the Allen key bolt head not on it (socket head cap screw there called) and I hit it a few times as hard as possible with a hammer to jar it and also I “tap” around on the housing where the bolt is if able (not as hard as possible but firm, remember most of the time its an alloy housing and it doesn’t take much to crack it), start tapping lightish and build up the firmness, this way you wont run the risk of cracking it….
So far I have never had to use penetrant or heat up any housings to remove seized bolts at home or at work, prior to this yes…. in my job I cant afford to heat up housings etc as there are too many seal surfaces that can be damaged…

lemo32 wrote:

Got a 79 ltd kz 1000, Been sittin a while, anyway I need to get the two allen bolts out of the rear brake caliper. I was going to use a low grade propane torch, bernzomatic, heat up the bolts to brake the rust bond, but wondering if it might damage the aluminum housing, any ideas?

Would first soak assembly in 50-50 mix of ATF/acetone (as suggested by MFolks) for a day or so, and again attempt to remove the bolts.

If bolts remain stuck, would heat the housing on opposite side of bolt heads (i.e., where the bolts screw into). The idea being to expand the aluminum surrounding the tight threaded portion of the bolts.

Attempt to loosen while still hot. Because will re-tighten as it cools and contracts to unheated size.

Remember to replace the o-rings upon reassembly. As the heat will likely damage them, and they should be replaced anyhow, even if heat isn't used.

Good Fortune!