Caliper rebuild question

just rebuilt front caliper for my XJ650J many thanks to Len @XJ4Ever.com for the kit with exactly all the correct parts. I might add the special red rubber grease for use on the piston seal inside the caliper (and safe for use with brake-fluid) makes manual compression of the piston into the caliper much easier. Also many thanks to the members on this site for the excellent tutorials on the rebuild.

question: The 82 xj650 maxim caliper has a threaded pivot bolt (that the caliper is free to rotate on) that screws into a threaded mount on the fork - then you add a lock washer and a nut to the pivot bolt on top of that. My question is what should the torque be of the pivot bolt into the fork mount (i.e. before adding the lock-washer and nut to the bolt). It seems to me that it should almost nothing so as to create as little drag as possible as the caliper is meant to rotate freely on the pivot bolt. Then you add the lockwasher and nut and torque that down snuggly with some medium threadlocker. If you tighten the bolt into the embedded fork mount to any degree it does restrict the caliper quite a bit from freely rotating about the pivot bolt. so what is the correct torque of the pivot bolt into the fork threads (before adding the lock-washer and nut) ?? Can't find that torque spec anywhere

 

Did you remember the bushing? The spacers?

 

yes.....two washers, sleeve, and O-ring. I'm probably over thinking it but I just don't know how tight to torque that pivot bolt before putting on the lockwasher and nut. I "want" to hardly tighten it at all and rely on the lockwasher and nut

 

I've never had a caliper get snug from tightening the bolt. The sleeve and the washers prevent it from happening. Don't forget to reinstall the dust cap if you still have it, too.

 

Just put it in finger tight and torque the nut to 18.8 ft lbs. Use a wrench on the bolt to keep it from backing out.

 

ok thank you, I'll tighten it then. I love these XJ's but this caliper design definitely isn't my favorite!

 

I actually think it's pretty cool. No sliding pins to wear down or re-grease. Not much risk of binding.
They're a bit funky to work on though.

 

I think it's the easiest one to work on

 

just seems like there is always too much drag (i.e. pads on the rotor) even when it's working as it should be

 

Disc brakes always have a little drag… Even on vehicles

 

Especially if you installed new pads, there will be more drag untill they "break in" to the disc wear.