Brake cylinders

[MacD]

I’m having great difficulty trying to remove my front brake cylinders, The retaining nuts nuts are worn and rusty. I’ve used WD40 tried heat but they won’t budge, any help much appreciated.

[philthehill]

If you are going to replace the cylinders just grind the heads off the bolts.
If not use Plus Gas instead of WD 40 as Plus Gas is especially formulated for the release of seized bolts.
Take care with the small bolt as it is easily sheared.
When assembling smear the threads with copper grease to alleviate any problems in the future.

[simmitc]

If the heads are already worn, then invest in new bolts when fitting the new cylinders, it will make life much easier.

[oliver90owner]

A small hole drilled immediately adjacent, and parallel, to the threads often suffices to allow removal if an item if it’s to be saved. An angle grinder is good for chopping off dead item fixings to speed up removal.

As PTH, not WD-40 that is a water dispersal product, primarily.