caliper bolts-a-go-go.

[Siberman]

I checked the brake pad thickness last weekend and found them to be worn out so I took the calipers off and put in some new ones. I don't normally tackle the brakes but it is becoming difficult to sort it out through a garage because I use the bike daily. Learning by doing and Youtube, I managed to clean up the pistons and bleed the brakes so that they are back to spec. What I found along the way was that the caliper bolts wouldn't screw up properly, as in they reached the torque setting 6mm early. After reading some of the posts here, I found out that the bolts are very soft and ought to be replaced as part of the overhaul. I ordered the bolts from Kawasaki parts, OEM ones, as I wondered if the ones on my bike were too long or something. When I compared them I found that the garage had used bolts with a steeper thread pitch and that was, I think, why they were tightening too early. Does this sound plausible?

[Topbox]

If by steeper thread pitch you mean a different thread to the OEM calliper bolts then that's exactly why they are torquing up early.

Going forward great care should be taken as the threads in the fork legs are probably bolloxed.

If you know the garage that fitted them take them back and demand new fork legs.

I don't know if I would helicoil a thru hole used for calipers?

Possibly an engineering shop who can ali weld could refurb them. But in any event I I regret to say your bike could be dangerous without inspection.

TB

PS if when you offer the old and new bolts together on the threads they should dovetail exactly, if not then different threads. It's not impossible either the caliper bolts use a fine thread, if someone has used standard then trouble.

[Topbox]

I've just remembered. Its not the fork leg thats threaded its the Caliper.

These are steel. I think a heli coil would work  ok in a steel caliper if its thick enough you dont want it protruding onto the disc.

TB

[Siberman]

Ah, you’re right. I think that the thread isn’t completely destroyed as the new bolts have tightened up to the correct torque. Do you regularly use brake cleaner on the pistons? Mine were quite crusty which I guess is because they often get wet where I ride.

[Topbox]

Glad it's sorted.

I clean mine twice a year. Just before winter hibernation and mid season

TB