Stripped Caliper threads

[OpFlash]

Hey there was having a wonderful day working on the XJ until I STRIPPED THE FREAKING THREADS ON TOP HOLE ON LEFT FRONT CALIPER!!! Crap! before this happened I actually solved one problem. Squeaky breaks front and rear. cleaned and used proper brake lubricant on correct caliper points / slides and then aligned up the front end nicely. anyway during the process of putting the left front caliper on I stripped out the top hole. I did check other threads didnt really find everything I was looking for so here are my questions.

First off proper torque specs for caliper mounting bolts? didnt find this in owners manual but saw general torque specs for 14mm bolt at 61 foot pounds is this correct.

My caliper bolts have a lock washer then flat washer on them first before going into mounting holes on lower fork legs is this correct? This is how they were when i got the bike.

What is the size / thread pitch etc for the stock bolt?

What would be the next size up from this stock bolt with suggestions as to best thread pitch etc?

Thoughts on Heli-Coil vs. re tapping and finding another bolt.

Thanks again

[TopCatGr58]

The thread size/pitch isn't listed, but you've got one from the other caliper, just take it off to match! The torque value is only 27ft/lbs for that bolt. Now for repairing, the diagram looks like there might be room on the other side where the caliper bolts to the fork, so I would think you could just find a bolt and nut combo that would fit into the stripped hole! IF there isn't much room on the inside edge of the fork tube and the wheel, then you might be able to run the bolt from the inside edge outward towards the caliper! Just an idea that might be easier than drilling and helicoiling!
T.C.

[OpFlash]

TC Thanks for the option I will take a look at that route tomorrow. Ok 27 ft/lbs for the caliper bolts. Any idea on the washer set up for those bolts?

[OpFlash]

Couldnt wait just took a peek in the garage. There is PLENTY of clearance to allow a nut and a longer bolt. I am goin to go this route as I know that retapping to allow for a larger bolt will mean that I would have to drill the mounting hole on the lower fork a bit larger. I would rather go the bolt / nut way than ruin or alter a 2nd part. Besides if it bothers me that much I could always buy a replacement caliper. However I think the longer bolt / nut will do the trick. Thanks again I tell ya, and I think Im speaking for alot of people when I say this. Without this forum and all the wonderful members it has many of these classics would never make it back out on the road

[pggg]

Those maxim front calipers must be a bit different from standard calipers, on a standard the top caliper hole won't take a bolt and nut without modifying the caliper as a nut won't sit flush, and the bottom caliper hole won't take a nut as it'd hit the rotor, Op if the nut/bolt does fit yours, then no prob, I did similar with my gsxr calipers, I used high tensile bolts with fine thread

[pggg]

Also fully threaded bolts are actually called set-screws, you really want bolts - that's threadless with the thread only where the nut fits, I previously filled the threads with JB weld(liquid steel) to turn the set-screws into 'bolts' for what it's worth..

[andreashweiss]

I have front calipers from the 81 special in my parts pile. , Sounds to me like you have a similiar setup to those awful calipers they put on the specials on the front. Anyone know if they are the same ? Mine will come to you with as a complet unit with nuts/bolts, etc. andreas PM please.

[rman]

for what its worth

I would advise the hardware to be assembled in the following order:

Bolt, locking washer, and then flat washer. The flat washer will be against the work and the locking hardware sandwiched between the flat washer and the bolt head.

But then again...... read my sig.

[trbig]

It would seem to be easier to just get a used one, then fix that one with a helicoil on your own schedule. They work great and will last the lifetime of the bike... and still look stock. Just my 2 cents..


Tod

[John]

Originally posted by andreashweiss
I have front calipers from the 81 special in my parts pile. , Sounds to me like you have a similiar setup to those awful calipers they put on the specials on the front. Anyone know if they are the same ? Mine will come to you with as a complet unit with nuts/bolts, etc. andreas PM please.

Andreas, the calipers are not the same from a Special to an XJ. I have a few sets of each, and they attach to the fork tube differently. I would recommend a heli coil type repair.

[OpFlash]

Ok today I went out to the garage and decided to go the easier route. I went to NAPPA auto parts and sized up the original bolt. Unfortunately they didnt have the right sizes in stock. They did have a very similar size in SAE which also had the same head size as the original bolt. I also purchased a nylon lock nut. Anyway I got home and installed the nut and bolt and It worked out just great. I did use the lock washer and flat washer like it had before only difference is that theres a nut on the other end holding everything together. There really is no clearance problems. Also the lower bolt was not stripped at all and was grabbing very well so i think that the problem is solved. Ill keep my eye out on a replacement caliper down the road and would possibly change it out while doing a brake job / etc. Ill post some pics so you can see how it turned out.