Stripped caliper--hexicoil bidirectional thread?

[Chuck_SA]

One of the brake caliper bolts on my 98 XJ is missing. Bought a new bolt from dealership, but the threads are stripped on the knuckle. Too much material missing to retap with same size. Did a search and saw helicoil inserts were a solution and had a question about them. I don't want to pull the knuckle so I would be drilling from outboard to inboard. Can I tap from outboard to inboard also considering the caliper bolt will be entering from the inboard side? Or, is the tapping tool small enough to tap from the inboard side of the knuckle?

Thanks much!

-Chuck

 

[5-90]

Doesn't matter which way you run the tap thru - it's going to be a right-hand thread either way...

The main issue you will have is keeping the drill going in on a perpindicular - if you can get away with it, remove the mount bracket or knuckle (whichever is smaller!) and use a drill press to do the drilling and to guide the tap. Going by hand, you'd better have a lot of practise at starting things straight, or you can scrap the knuckle and be looking at a weld/fill job.

I've got a lot of faith in Heli-Coil inserts. Done properly, they'll last pretty close to forever...

5-90

 

[Chuck_SA]

The knuckle slide surface is worn from where the pads were improperly seated due to the missing caliper bolt I assume. Was going to see if a friend could put some weld in the grove and file it to shape. If I have to pull the knuckle to tap it right, I may as well pick up a knuckle from a junkyard and kill two birds with one stone.

Something else odd I noticed was my FSM shows the two-edged knotch on the brake pad sitting on the bottom slide of the knuckle. The pads are currently installed with the two-edged knotch sitting on the upper slide. This is the passenger side and the outboard pad has the letter L on it. Is it possible to put the pads on the wrong side or are they keyed to prevent that?
Service records show Brake Check worked on it last. Don't know how they are in terms of quality.

Thanks,

Chuck

 

[bustednutz]

I had the exact same thing happen to me on my 98 XJ about a month ago.
I was pretty straight with the drill and tap by hand. I used the Helicoil system.
Holds tighter then ever.
I will admit that I was not exactly straight with the drill. Approx 1-2 degrees off. Didn't really make a terrible difference.
Helicoils work. I'm sold on them.
Just make sure your drill bit is dead center on the hole. and go slow with it. Take your time and use lots of lubricant on your drill bit. Be patient and the results will be great.