How to remove rounded bleed screw

[Dexter]

So i managed to destroy the bleed screw on my rear caliper. I was super careful, used a correct size brake spanner but it was just utterly seized, and now it's pretty round. Any top tips on how to remove it? I wouldn't want to replace the whole caliper.

[Finch]

3 hours ago, Dexter said:

So i managed to destroy the bleed screw on my rear caliper. I was super careful, used a correct size brake spanner but it was just utterly seized, and now it's pretty round. Any top tips on how to remove it? I wouldn't want to replace the whole caliper.

I assume you mean the nipple? The oldest most recommended trick is to get a deep socket 1mm smaller than the nut hammer it on and remove it with a breaker/ratchet and then get another nipple and replace it. The probability of removing the nut is going to be slim AF unless you can super-freeze the socket to silly low temps and pull nut out, so get a socket you're not too bothered about binning (cheaper than a new caliper!!)

 

Other than that there is the possibility of drilling through the middle and using a tap-die, thread it to accept a different bleed nipple IIRC the Micra/March K11, Almera, Primera P11 ones are around 2-4mm thinner than the Honda ones so if you found their thread size might work to thread in? Or a motorbike one might work aswell.

 

Another method would be to chop it off with grinder flat to surface face, drill out remaining bit, tap it wider than you need, fit a helicoil and replace with an OEM sized nipple - though not sure how well heli-coil's would work with fluid? or a combo of this and above might work tbh

 

Or very worst-case scenario, look for a machine shop near you that does various engineering tasks, has a lathe etc and give them the caliper ask them to remove the nut and maybe re-thread if they need to (I.e if they drill it out) - I'd get a new nipple in-case they do  and ask them to thread to that size. DemonTweeks in the UK have various brands including Goodridge ones in stock in various sizes but might be cheaper to get something closer to home.

 

Before you refit the caliper, if you're drilling or tapping i'd get some fluid and flush the caliper out to clear any metal particles inside, basically filling up with fluid until it starts leaking then let drain over night, dry and flush with compressed air too this stops the chance of a fragment working through to the rubber boot or jamming the piston up

Edited September 25, 2016 by Finch

[Dexter]

Thanks Finch, i'll start with the smaller socket and some freezing spray... and very crossed fingers!