Stripped Caliper Mounting Bolt Hole

[tosacruiser]

While bleeding brakes, I found that the bolts holding my passenger side calipers were loose - and loose to the PO probably zipping them in with an impact driver. The threads in the upper hole are all gone, but the bottom hole is marginal. With brakes being probably the most important part of the vehicle I did some digging/searching on here Essentially there are three options:

• Drill and tap to 1/2-20 bolt size - opposed to this route, since everything else is metric
• Timesert - mixed reviews if you have to pull the knuckle. (Helicoils get mixed feedback for this application)
• Get used Knuckle, then would need to rebuild knuckle. Repair the old one for a spare while off vehicle.

What is the consensus on tackling this issue? Does it influence any thoughts that there is some seep/weep of grease at the knuckle - was rebuilt by PO, but now I am second guessing his work.

 

[cruisermatt]

Helicoil or timesert is fine. We have to do these fairly frequently. Good used knuckles are getting harder to find as they are popular for FJ40 disc brake conversions. Make sure you replace the bolts with new OEM Toyota as well

 

[dbbowen]

ill second @cruisermatt. Ive done both helicoil and timeserts and got the same results. Timeserts make you feel better about it because you spent more money, but in my experience the helicoil worked just as well

 

[aztoyman]

As mentioned already, a threaded repair insert of choice is best. If you have the room, a longer bolt and a flanged nut (or nut and washer) on the back side would be a good trail fix to get you home. Or it could turn out to be one of those "temporary" fixes that end up being permanent.

 

[CruiserTrash]

Weld it and forget about threads - or removing it - ever again!

Just kidding. I think @Fyffer did helicoil as well. I've been on the trail with him many times and no issues with stopping.

 

[Malleus]

After using Timeserts for the first time, you'll never use anything else. IMHO, they are far better than Helicoil inserts.

 

[Fyffer]

Weld it and forget about threads - or removing it - ever again!

Just kidding. I think @Fyffer did helicoil as well. I've been on the trail with him many times and no issues with stopping.

Nope, did go the timesert way. Reported as more reusable vs Helicoils from the U tube university. But also they were for my -71, 4 runner calipers I rebuilt for the 60. Yes, new bolts and a new brake line stick I had to bend.

Sorting out my Frankie is not always that easy, PO did stuff.

 

[tosacruiser]

Thanks - going Time Sert route since I’m bound to have to do it somewhere else.

I’m ordering the M12 x 1.25 Time Sert kit tonight, did you get by with the 15mm inserts that come with the kit?

Also might as rebuild the knuckles while I’m in there - assume doing the wheel bearings is good to do while everything is apart?

 

[Fyffer]

Thanks - going Time Sert route since I’m bound to have to do it somewhere else.

I’m ordering the M12 x 1.25 Time Sert kit tonight, did you get by with the 15mm inserts that come with the kit?

Also might as rebuild the knuckles while I’m in there - assume doing the wheel bearings is good to do while everything is apart?

Yes, use them. Drilling alignment is crucial.
A MUD thread

Frightening Discovery with Sano Recovery: Front Caliper Bolt Crisis​

@DrRock knows.

​

 

[Spike Strip]

Any thread repair will work. Time-Sert in probably the best. Be sure and use a few drops of RED loctite on the insert so there's no chance of it walking out. give the Loctite 24hrs to cure before reinstalling caliper. Make sure the insert and the caliper hole are scrupulously clean for the Loctite.

Good luck.

 

[TXIN]

I literally just did this with the Timesert kit about a month ago. Worked great with the 15mm inserts that came with the kit.

I did have the knuckle torn down when I installed them though.

 

[tosacruiser]

Glad to hear it. plan on rebuilding my knuckles while I’m there, worried about not getting good alignment if I do it on the vehicle.

 

[TXIN]

Glad to hear it. plan on rebuilding my knuckles while I’m there, worried about not getting good alignment if I do it on the vehicle.

Yeah, I'm not a machinist by any means and I thought it was challenging (at least nerve wracking) off the vehicle. I wouldn't want to try it with the knuckle still installed, personally.