My new parts arrived so this weekend I started on disassembling the brake calipers so they could be cleaned.
Before starting the job, I watched this video to get a general idea of the parts and the best method of disassembly:
When I bought my air compressor a few weeks back, I bought a toolkit to go with it. This toolkit included an impact wrench, or as I call them, a rattle gun. I figured it was worth trying on the bolts. I was cautious to hold the caliper down as hard as I could, in case the whole thing tried to spin, but the impact wrench made light work of the bolts. Not only were they out in seconds, but there was no damage to the bolt heads at all.
I did have 1 small issue, when I got to the second caliper, the bolts just wouldn’t move, no matter how much ‘wrenching’ I gave them. I moved on to another one, but had the same issue. I then found out that the gun had slipped into reverse and was tightening the bolts, not undoing them. This is probably because the kit was cheap, but if you’re new to air tools, I’d probably keep an eye on that. Once I had the gun going the right way, the rest of the bots were out in seconds. Once they were apart I removed the dust clips and seals.
Getting the pistons out was the next chore. In the video above, Stephen mentions there are 2 ways to get the pistons out of the calipers; Compressed air or mechanical leverage. I first tried the compressed air method, but my air gun wouldn’t make a good seal, although it did manage to cover me and the whole work area in brake fluid.
I tried levering out the piston with 2 screwdrivers, but no amount of force would budge them, it was just bending the screwdrivers. I soaked all the pistons in penetrant and also filled the calipers up with penetrent, then left them for a few hours.
When I came back, it still took a lot of force, but after about 30 minutes of soaking, levering, soaking, levering, they all started popping out. Once the pistons were out, I removed the inner seals. I started cleaning the calipers with brake fluid, but there is a fair amount of rust on them and I’m not convinced the dust covers will seal properly. I emailed AER who re-surfaced my exhaust manifolds for me, and asked if they could clean them up for me. I was surprised they replied on a Saturday, I wasn’t expecting a reply until Monday, but they said they could bead-blast them for me.