So finally got around to reiaring my brake lines.

The problem I'm left with is extracting the bleed nipples which are corroded and siezed-in solid?

Any suggestions much appreciated (new calipers expensive)

 

cut the lines close enough to put a socket on them hit them with penetrating fluid first then slowly loosen and tighten them till they free them selves.

 

They're tough to get out and IMHO not worth the effort. I had an older Vette and had to drill a few out and re-tap them. I was rebuilding the caliper 100% so I had no worry's about metal shaving inside.

If you're going to go thru your brake system, opt for the $60 each and get new calipers. They'll be rebuilt with new seals and slides.

Tim

 

I soak with Kroil, heat them up, tap a socket over the bleeder nipple and once they cool down I can usually spin them out. If not then it's time for some reman calipers.

 

Thanks guys.

I've watched several youtube videos so I think I have a plan.

Drill them out, but not too big or too deep
Heat the calipers around the bleedscrew.
Knock in some rectangular-type screw extractors (impact helps loosen)
Then unscrew (in theory)
If all that fails, buy refurbs (hard here in UK)

 

I use pb blaster and tap the caliper housing with a ball peen around the bleeder screw. Only use heat if nothing else works and don't use those mobydick looking visegrips, use the rounded jaws. Patience required.

 

So far so good, rear bleed-nipples done!

This is how:-

1. Drill out with a 5mm drill to approx to the hole is in the nipple i.e. stopping short of the nipple-end
2. Heat the calipers around the bleedscrew (no need to go extreme)
3. Spray penetrating oil inside the nipple to cools and help break the bond.
4. Knock in a 5mm rectangular screw extractors (see
   here
   here
   ),the impact also helps break the bond.
5. Use a wrench and un-screw the nipple.

Done two so far, both were badly rusted with no flats and little exposed metal left, they came out realtively easy I have to say.

Had that failed there was the option of a Nipple Therapy Kit, no its not a wind-up it really exists, some of my friends here in the UK have used it with 100% success.

 

Nipple therapy looks like a great kit. I wonder if it would work on cast iron calipers?

 

Well it should, the original cast iron was drilled and tapped I presume.

Just to add I successfully extracted 4 very badly corroded bleed nipples, as follows:-

1. Drill out nipple down to the end of the original hole. Do this 1st with a 3mm drill, the open-out with 5mm drill.
2. Heat with a MAPP gas torch (cheap to buy) but only around the nipple. Shield any brake hoses with a metal guard. No need to go to extreme here.
3. Spray penetrating oil down the nipple to cool it down and help break the bonds.
4. Tap-in 5mm sized Teng tool until it stops, again hammering helps loosen the nipple.
5. Use a wrench to unwind the nipple, all mine came out will little effort.

I watched some YouTube videos where the guys used oxyacetylene to really get the area hot, so much so the brake fluid started to vaporise. In fact they had to repeat this a couple of times. This seemed extreme, I think it's all about breaking bonds.

I'd say it takes takes 10-15 mins to do each one, quite safely, the biggest risk is breaking a drill in the hole so take this slow and steady with good quality drills.

 

In the video his were in much better condition and at least were recognisable as nipples, some of mine had crumbled away with little-left to grab on to, it also took him a lot longer so my 10-15 mins was a bit conservative, probably 5mins

Have to say the screw extractors were a quantum-leap, I wouldn't be surprised if their smallest bit would work without all the drilling and heating, well worth $11