Coroded bleed screws

[mgbgtn]

Anyone had any luck removing bleed screws from the rear calipers after they have had 20 years of exposure to salty westcoast air.or are the calipers just junk?

[azruss]

lots of patience and penetrating oil. they are pretty easy to break off.

[spider2081]

I would add heat with the penetrating oil. I blow the piston out with compressed air first to make sure the caliper is worth the effort. If the piston or the caliper cylinder are no good no need to get bleeder out. I would exchange the caliper for a rebuilt one. I have used a bleeder repair kit with good results. You drill out the existing bleeder and tap the caliper for an 1/8 pipe thread. Then install the new seat and bleeder.

[narfire]

Can't remember who here mentioned it several years ago but a great tip... Try and tighten the screws just a tad and then undo. But lots of penitrating oil,heat and paitence. If they do break off, I'd recomend the welded nut trick to get the thing out. I've tried to drill, but the two times were unsuccessfull and trashed the calipers.
Good luck.

[mgbgtn]

Thanks for the help. Lots of heat and penitrating oil seems to be the key.

[124JOE]

i was told once along time ago
to heat and touch a wax candle to the bleeder
then crack it loose quick

also drilling "for the most" will ruin it

i do like the weld a nut idea
and penatrating fluid,but never tryed it "yet"!

[thewizard]

Yep, should be "most" will ruin it if they try drilling it.
A good machinist can get it done with good results.
It is imperative it is done in a good setup preferably in a mill.
If you don't get your initial hole exactly centered you will more than likely be screwed.
Drill to tap drill size and clean out remnants with proper tap which is 8MM X 1.25 Metric.
It is not a pipe tap, it is a straight thread.
There are still a couple other tricks to this job like not drilling to deep by setting down feed stop so drill does not suck all the way through.
From my experience just dusting the aluminum caliper renews the bleeder screw seat. The 118 degree drill point angle seems to work fine.
Most shops won't do it as isn't cost effective nor a particularly fun job.
It can be done, I did it Monday with great results.
Took me about 45 minutes would translate into $45-80 depending on shop rate.
If you can't do it yourself you will have to buy re manufactured or new.

[narfire]

Forgot to mention but with the tighten first thing, I read that a few light taps on the bleeder first might help break the rust bond as well.
Was that you Trey that brought that tip up?
Anyway it has worked for me as I was busting screws on a regular basis and ended up with the welded nut most of the time.
Chris

[majicwrench]

I've drilled em before. The hole in the bleeder make a wonderful pilot hole. Goes pretty quick.
But I would rather get em loose. Tap tap. Heat, cool. Tap tap. Heat cool. Dexron/acetone mix for lube. Tap on all flats sideways, heat cool. Tap tap on caliper aournd bleeder. Be gentle on all of this. Tap tap. Try again tomorrow. Tap tap. It'll come.

[thewizard]

Lots of good advice here from fellow posters. Be sure and try it out first.
When time is an issue sometimes it's just faster to break something and get on with it.
Just sayin'
In my current line of heavy equipment machining and repair we often get mangled equipment in to repair with no prints, sketches, whatever. They just tell us to fix it, say we can't buy it or to much downtime.
Lot's of times it is just faster to destroy something on the way to rebuilding it.
Some things take way to long with conventional thought. Have to think out of the box.

[thewizard]

Majic, you are so correct using the bleeder hole as a reference.
You get it lined up correctly, tap drill and tap. That's it.