# Caliper nipple stripped



## stranger12 (Apr 24, 2015)

Hi all

I changed my caliper to evo 9 and 350 disc in dec

One of the calipers was leaking from piston so took it off and rebuilt it today

Car was off road for 6 month plus and caliper was in a box

When i was rebuilding today, i opened the two bleed nipples and noticed the thread coming off with it

Did some googling and think it is to do with galvanised rust( sorry if that is not the right term)


Bottom line is, it is leaking and can't put the nipples back

It is an m10 x 1.0 so bought both helicoil and tap and die for it

I want to try and tap it first and if that fails then drill next size up and helicoil

Question i have is, if existing thread is gone, is there any chance the tap works?

I guess if there is no metal then it can't tap or re create the thread

I then thought of taking it to someone to weld it and drill it again but not sure if they will **** up the bleed hole or not

What would you do ?


I am so angry and annoyed and think the issue happened due to no brake fluid been there so the bolt freezed


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## Miguel - Newera (Sep 18, 2003)

I'd take the offending caliper (& possibly the opposite side) to a good machine shop and ask them to sort it - use stainless bleed nipples to avoid this happening again.
You'd probably ruin the conical base which forms a seal for the nipple once tightened if you try helicoiling. Shouldn't be too expensive for a machine shop to sort it out properly, either.


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## stranger12 (Apr 24, 2015)

I have helicoiled it and it seems ok but I am worried it will give up.

The helicoil seems cheap to believe it can hold the nipple in place under few hundred if not thousand PSI.

a shop is asking for £90 to fix that single hole which seems very dear and expensive .


I search for maching shops using the term fabricator or machine engineering shop on yell an didn't get many results.


on the helicoil, It is very soft material, do you reckon it is strong enough ?
When you helicoil, do you need to counter sink the top so the screw can thread into it ?

I bought an M12 bleed nipple which does not screw in but the helicoil does. there seems to be a problem with the thread guide on top which makes me think I need to counter sink it .


I am trying to do all I can before I pay £90 to fix that hole. The caliper did cost me £80 only !!


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## TAZZMAXX (Mar 9, 2010)

The helicoil insert is stronger than the original thread it has repaired but it won't be fluid tight, maybe that's why the machine shop want £90 - to weld, drill and tap?


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## stranger12 (Apr 24, 2015)

he is not welding 

he said they are inserting a tube or pipe cut to size and at right angle.
the outer of that pipe threads into the caliper bleed nipple body to whichever size they tap it to and the inner size will be m10x1 which is what I need for the nipple

They will use thread lock or whatevery he mentioned which will almost glue that pipe in place.


what term will you use in google to try and find other machining shops ?

I am happy to pay £90 if he was to weld and re tap but his solution is almost helicoil but done with machine at right angle and ....


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## TAZZMAXX (Mar 9, 2010)

CNC machining, general machining, toolmaker, conventional machining - useful searches.

Don't be surprised if you don't get warm responses off them though as most businesses I know don't like working for Joe Public (me included:chuckle and would sooner just deal with other businesses instead. You sometimes get quoted inflated prices just to put you off. Sorry, that's the way it is. 

As you say, they are doing a version of a helicoil repair.

I'm afraid you can't cut corners on brakes, suspension or steering components on cars. Without being alarmist, what's worth more to you, a cheap caliper repair or avoiding a long stay in hospital? I know what I'd choose. I'm not saying repairs can't be carried out successfully but you want to know that they've been done correctly.


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## stranger12 (Apr 24, 2015)

very true when I called few places most were reluctant.

do they not want business or is it too small for them ?

if you tighten it up and it doesn't leak, would that mean the helicoil is safe in your view ?

I obviosuly don't want to risk a £20 k car ( after all mods) and 1K I have spent on brakes for £90 and most importantly mylife.

if the brake holds then I assume it will continue to do so .

I think in worst case scenario of it leaking, it will be spongy but will still stop you


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## TAZZMAXX (Mar 9, 2010)

Heicoils are great bits of engineering. At the very least though, fit it with a hydraulic rated thread locking adhesive before screwing the nipple in and you may be okay. If it leaks though, look for another caliper.


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