Date: 05-11-25  Time: 16:23 pm

Author Topic: Rear Caliper Stripped Thread  (Read 6163 times)

darrsi

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Rear Caliper Stripped Thread
« on: 28 October 2014, 06:33:51 pm »
I'm not sure how it really happened because i always use copper grease and a torque wrench, and i'm not heavy handed anyway, but i've managed to strip the thread on the rear caliper where the back pad pin goes.  :'(
There's a tiny bit of bite there so i've Loctite'd it for now, but was wondering if it can be safely helicoiled or not?
There doesn't appear to be much room to play with, and was also wondering if there's a chance i could damage a brake fluid chamber as well?

Has anyone tried this before, or are there any other options other than a replacement caliper?
 Cheers, Darrsi.  :\

greenman

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Re: Rear Caliper Stripped Thread
« Reply #1 on: 28 October 2014, 07:26:32 pm »
It might work out cheaper and perhaps safer to look on eBay..

JoeRock

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Re: Rear Caliper Stripped Thread
« Reply #2 on: 28 October 2014, 09:24:30 pm »
I'm not sure how it really happened because i always use copper grease and a torque wrench, and i'm not heavy handed anyway, but i've managed to strip the thread on the rear caliper where the back pad pin goes.  :'(
There's a tiny bit of bite there so i've Loctite'd it for now, but was wondering if it can be safely helicoiled or not?
There doesn't appear to be much room to play with, and was also wondering if there's a chance i could damage a brake fluid chamber as well?

Has anyone tried this before, or are there any other options other than a replacement caliper?
 Cheers, Darrsi.  :\
Are you by any chance using copper grease and still using the torque settings recommended by the manufacturer? THat'd be why! Most torque settings are dry threaded (unless specifically saying otherwise), if you put copper grease on you need to drop the torque by about 25% in order to stop the threads from deforming as they slide easier with the grease on, thus giving you a false reading!

darrsi

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Re: Rear Caliper Stripped Thread
« Reply #3 on: 28 October 2014, 10:10:08 pm »
I'm not sure how it really happened because i always use copper grease and a torque wrench, and i'm not heavy handed anyway, but i've managed to strip the thread on the rear caliper where the back pad pin goes.  :'(
There's a tiny bit of bite there so i've Loctite'd it for now, but was wondering if it can be safely helicoiled or not?
There doesn't appear to be much room to play with, and was also wondering if there's a chance i could damage a brake fluid chamber as well?

Has anyone tried this before, or are there any other options other than a replacement caliper?
 Cheers, Darrsi.  :\
Are you by any chance using copper grease and still using the torque settings recommended by the manufacturer? THat'd be why! Most torque settings are dry threaded (unless specifically saying otherwise), if you put copper grease on you need to drop the torque by about 25% in order to stop the threads from deforming as they slide easier with the grease on, thus giving you a false reading!

You live and learn.  :(
As simple as that sounds, it does make perferct sense.
Saying that, i don't remember ever stripping a thread before that i can think of?
It was only 10Nm as well.
I'm weighing up my options and it would seem that the logical option is replace the caliper.
I have a machine shop and engineers at work but if anything unexpected happens it leaves me without a bike which is my only transport plus i'm on call for work every other week for work so i have to be ready to go.
Oh well, shit happens.
Cheers for the insight though, definitely one to remember in future.

darrsi

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Re: Rear Caliper Stripped Thread
« Reply #4 on: 28 October 2014, 10:42:43 pm »
Well this kind of reinforces that theory, and there was me thinking i was doing things correctly!

http://benmlee.com/4runner/threads/threads.htm


bootz76

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Re: Rear Caliper Stripped Thread
« Reply #5 on: 28 October 2014, 11:37:01 pm »
Should be fine to helicoil.as you have access to engineers etc you could drill a hole in the pin and use an R clip like the front pins

bootz76

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Re: Rear Caliper Stripped Thread
« Reply #6 on: 28 October 2014, 11:39:55 pm »
Or fill the hole with weld drill and tap a new thread

bootz76

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Re: Rear Caliper Stripped Thread
« Reply #7 on: 28 October 2014, 11:41:42 pm »
Or or drill the head of both pins and lockwire them together

darrsi

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Re: Rear Caliper Stripped Thread
« Reply #8 on: 28 October 2014, 11:46:28 pm »
Should be fine to helicoil.as you have access to engineers etc you could drill a hole in the pin and use an R clip like the front pins

The issue with the helicoil was lack of space around the hole, and whether i'd tap into a fluid channel or chamber?
Was hoping someone may have attempted it before.

darrsi

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Re: Rear Caliper Stripped Thread
« Reply #9 on: 28 October 2014, 11:50:04 pm »
Or fill the hole with weld drill and tap a new thread

For something that is removed once or twice a year i was rather hoping for an easier solution, i'll look into this as a possibility.

His Dudeness

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Re: Rear Caliper Stripped Thread
« Reply #10 on: 28 October 2014, 11:54:44 pm »
Is it a hole for the small allen head bolts that hold the pads that is damaged?

darrsi

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Re: Rear Caliper Stripped Thread
« Reply #11 on: 29 October 2014, 07:51:41 am »
Is it a hole for the small allen head bolts that hold the pads that is damaged?

Yeah, the pad pin caliper thread, as you look at the caliper the one on the left at the back.
The pad pin thread is totally okay as it's steel.

Jules-C

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Re: Rear Caliper Stripped Thread
« Reply #12 on: 29 October 2014, 08:54:37 am »
The caliper pins holes are a long way from any fluid channels drill out and helicoil shouldn't be a problem

unfazed

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Re: Rear Caliper Stripped Thread
« Reply #13 on: 05 November 2014, 05:55:43 pm »
Should be fine to helicoil.as you have access to engineers etc you could drill a hole in the pin and use an R clip like the front pins

+1 to the above  :thumbup

darrsi

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Re: Rear Caliper Stripped Thread
« Reply #14 on: 05 November 2014, 10:35:51 pm »
Should be fine to helicoil.as you have access to engineers etc you could drill a hole in the pin and use an R clip like the front pins

+1 to the above  :thumbup

Where though??
Can't see where the 'R' clip would go?

unfazed

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Re: Rear Caliper Stripped Thread
« Reply #15 on: 06 November 2014, 08:41:46 am »
Between the caliper body and back of pad. Would get you out of trouble.

darrsi

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Re: Rear Caliper Stripped Thread
« Reply #16 on: 06 November 2014, 12:12:57 pm »
I have a replacement on the way now so I will have a bit of time to see the best way to go with my old one.   :)

unfazed

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Re: Rear Caliper Stripped Thread
« Reply #17 on: 06 November 2014, 07:48:42 pm »
And you will have the weekend to fit it  :)