Broke caliper bolts, now what? (1 Viewer)

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Mar 1, 2019
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Location
MD
Broke both caliper bolts on pass side doing pad/rotor/bearings/seals on my LX. I'm guessing I should be sourcing a junkyard knuckle? How hard of a job is replacing the knuckle over my initial plans? Any help/suggestions welcome!
 
Bummer-

Ive never had any success with reverse thread, left hand drill bit, ez out or similar- just a waste of time and $$. Your situation is a large bolt high tensile strength that is frozen/welded to the knuckle- not much hope of backing that out.

My advice would be take the knuckle off- and attempt to drill out the bolts (using proper prep methods) and cobalt drill bits( several of them). If youre not equipped to embark on that task, find someone locally that has an EDM machine that will burn the bolt out.

Last resort is buying a second hand knuckle.
 
Bummer-

Ive never had any success with reverse thread, left hand drill bit, ez out or similar- just a waste of time and $$. Your situation is a large bolt high tensile strength that is frozen/welded to the knuckle- not much hope of backing that out.

My advice would be take the knuckle off- and attempt to drill out the bolts (using proper prep methods) and cobalt drill bits( several of them). If youre not equipped to embark on that task, find someone locally that has an EDM machine that will burn the bolt out.

Last resort is buying a second hand knuckle.
Yea, caliper bolts are always hard for me; the heat cycling, water exposure, and the fine threads always make it tough. I think I'll try pulling it off and take it to a machine shop first.
 
The toolmakers at my work will soak snapped bolts with PB blaster then use an engraving tool to basically vibrate the broken piece out.
 
WOW the two bolts holding on caliber are hard to bust. Not something I've dealt with, but assume they're not only corrosion issue with knuckle bolts & speed sensors. Interesting this may be why 200 series FSM calls them non re-usable. I feel for the rigs in the rust belt, PITA!

If overall condition of knuckle is bad. I'd be inclined to replace steering knuckle. I like pulling and recondition knuckle first time in on a 100 series. It's not hard, just takes more time and a puller for the ball joints.

If not all bad. I'd just grab my drill with very good bits and start small. Starting at dead center of busted bolt is key. So I flatten and use center punch to guide. Keep working up size of hole until near the threads in knuckle. Then use thread restoration tool to remove last remains of bolt.

If I had access to a welder, it would be first choice. Welding on nut/bolt heating to a red glow. Google videos of this and you'll see how well this works.
 
Was going to suggest X2 on welding a bolt to remaining stud if you can. Works well.
 
Easiest IMO, especially if you don't have access to a welder and or there isn't much old bolt threads exposed. Pull the knuckle off and find a machine shop in your area, they should be able to remove it for you.
 
Was it cross threaded? Only reason for the breakage, i don't think rust can seize a bolt up this size for it to break. Your only option now is to remove the knuckle, drill and tap new threads and use a bigger bolt. Or just get a new used knuckle from a junk yard.
 
Thanks guys, still have to get it apart and see where it broke and if a nut can be welded on or not. I'll report back, hopefully have a chance in the morning.
 
Some of the biggest bolts on the 100 series I can think of that I've removed, are the trailer hitch bolts. I bust them off often with my 3/4 breaker bar. The part of bolt remains is not difficult or stuck usually. It usually leaves some bolt sticking out that I can grab. It was the corrosion around bolt that ate blot, weakening it. Not cross threading!

I've seem videos of very small bolt busted deep in a tough spot with none of the bolt sticking up. Yet a good weld builds up weld materiel and they come out. Number one, is affect of heat expansion (red hot) break lock on threads. Second is it now has something to grab (nut welded on) and turn. This is just one video I garbed. Some videos show about ever technique I can think of.


Me I just grab whats at hand and go at it. This usually means a drilling and my thread repair kit to get remnants of old bolt out without damaging threads of female threads I need. .
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Naturally pulling off steering knuckle (easy too do) make access easier.
 
Wow, thanks for the support guys. One of them seemed to have broken flush and the other one not as it seems to be preventing the caliper from sliding off. I'll probably have to cut a section of the rotor away to get the caliper to move toward the inside of the car to get it off. I don't have a welder, been wanting one for a while, might pick up a Hobart Handler 140 for things like this. Time to start dismantling this thing, I'll post back when I make some more progress.
 
I just had one caliper bolt break off just inside or below flush, so can't use welding technique. I am now mustering up the courage to try taking off the knuckle. Then decide how to proceed with drilling out rusted seized remaining bolt....OR replace with used junk yard knuckle.

Thanks for the replys to @erwall's thread.
 
I just had one caliper bolt break off just inside or below flush, so can't use welding technique. I am now mustering up the courage to try taking off the knuckle. Then decide how to proceed with drilling out rusted seized remaining bolt....OR replace with used junk yard knuckle.

Thanks for the replys to @erwall's thread.


Taking off the knuckle isn't hard at all, it's just really really heavy like everything else on this rig. I had to remove it when i rebooted my CVs, refer to that thread if you need some tips.
 
Taking off the knuckle isn't hard at all, it's just really really heavy like everything else on this rig. I had to remove it when i rebooted my CVs, refer to that thread if you need some tips.

I will search that thread. Thank you very much.
 
I will search that thread. Thank you very much.
Check out my build thread in my signature for some tips on tools to use to get everything loose on the knuckle - post #74. I tried to kind of compile all of the threads I read to get my knuckles off.
 
Check out my build thread in my signature for some tips on tools to use to get everything loose on the knuckle - post #74. I tried to kind of compile all of the threads I read to get my knuckles off.

Thanks. Right now I am not confident with my two wimpy jack stands in my gravel dryway. I currentley have one jack right beside the lower ball joint.
 
Ended up having to cut the outside plate of the rotor off to get clearance to pull the caliper off since one broke flush and one was sticking out. Just got my knuckle off this morning. Large pitman arm puller to the rescue, made short work of the tie rod end and upper, lower ball joints. I have a replacement knuckle on the way and I guess I better order a new speed/ABS sensor since, in my recent experience, and from what I've read on here, there's no way it's going to be useable again.
 
Ended up having to cut the outside plate of the rotor off to get clearance to pull the caliper off since one broke flush and one was sticking out. Just got my knuckle off this morning. Large pitman arm puller to the rescue, made short work of the tie rod end and upper, lower ball joints. I have a replacement knuckle on the way and I guess I better order a new speed/ABS sensor since, in my recent experience, and from what I've read on here, there's no way it's going to be useable again.
That's good progress!
My sensor came out without any drama and looked fine. I re-used them and I am not having any issues.

Thanks. Right now I am not confident with my two wimpy jack stands in my gravel dryway. I currentley have one jack right beside the lower ball joint.
I just had 1 jack and 2 6 ton jack stands for the whole job. I picked up the jack stands for $35 at harbor freight.
 
The only way I can think of to get steering knuckle off is by first removing caliper.

The front caliper is two parts. So may be possible to split it while on, IDK.
Try pulling the pins and remove the pads. Then remove all bolt from back side. See if front of caliper will separate. Then rotor disk can be pulled off with wheel hub.
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I've wanted to pull apart while rebuilding caliper. But kit has no seals or gaskets nor does FSM talk about. But they have cambers in them, with ports running from back to front.
 

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