PS_Bond Posted August 11, 2012 Share Posted August 11, 2012 After the fun of "why's it not running properly", I've returned to the original schedule - replacing brake lines & bleeding the system. The bleed nipple on the rear caliper sheared when I tried to open it, so I've now removed the caliper (cursing the fact that when I replaced the discs the use of stud lock rather than a medium strength locking adhesive seemed a good idea). The caliper is in a vice at the moment; I've drilled into the nipple to the end of the threads with a 7mm left-hand drill, which hasn't budged it. A screw extractor hasn't shifted it. Copious quantities of penetrating fluid haven't helped, nor has the (unusually for me) cautious application of heat. About the only thing I can think of that I haven't tried yet is welding to the remains of the nipple (or possibly carving out to the threads with a Dremel). At what point do I declare it a draw and treat the beasty to a nice new caliper (or possibly a matched pair)? Defenders - they really are the gift that keeps on giving, aren't they Quote Link to comment Share on other sites More sharing options...
Julian Posted August 11, 2012 Share Posted August 11, 2012 A MIG welder is maybe the answer. Put a blob of weld on the nipple so that you can get vise grips on it and undo. Chances are the weld blob sheared off, don't worry, just keep repeating the exercise. Eventually the continued heating and cooling will allow it to unscrew. (in 90% of occasions according to my mate)] Julian. Quote Link to comment Share on other sites More sharing options...
western Posted August 11, 2012 Share Posted August 11, 2012 be careful you don't cook the fliud channel rubber seals between each caliper half, Quote Link to comment Share on other sites More sharing options...
PS_Bond Posted August 12, 2012 Author Share Posted August 12, 2012 Well, swings and roundabouts. Carefully built up the weld inside the nipple (with pauses in the hope of not cooking anything) until I had something to get a grip on - and failed to grip it. Went at the weld with a LH drill (yay) and it bit & turned it out. That's the good bit - the procedure worked. However, the corrosion seems to have mostly been at the base of the bleed nipple (how?) - the seat doesn't look like it'll ever seal cleanly again. Ho hum. I don't feel happy about trying to grind that clean, so I guess it's new caliper time. Preferably 2, I think (opinions?). And it can have new pads at the same time... Quote Link to comment Share on other sites More sharing options...
unclemicky Posted August 12, 2012 Share Posted August 12, 2012 Thats the right option.Play safe!! Quote Link to comment Share on other sites More sharing options...
PS_Bond Posted August 13, 2012 Author Share Posted August 13, 2012 Now I just need to decide what colour to paint them... Assuming they don't have a painted finish to start with, that is. I've threatened to do them bright red, but my OH seems to think that's inappropriate (Yes, it'll probably be black - and the only reason for doing it is to make the next time I take them off a bit more pleasant!) Quote Link to comment Share on other sites More sharing options...
G4FUJ Posted August 13, 2012 Share Posted August 13, 2012 Dayglo yellow... More interesting than black (or red). Quote Link to comment Share on other sites More sharing options...
western Posted August 13, 2012 Share Posted August 13, 2012 don't bother because it'll all come off eventually with being exposed to road grime,stones & wet weather. Quote Link to comment Share on other sites More sharing options...
L19MUD Posted August 13, 2012 Share Posted August 13, 2012 I painted mine red (because I'm a tart!) Years ago with proper cailer paint. When (ha ha) I ever get round to cleaning it with a pressure washer the red paint is still there shining brightly :-) Quote Link to comment Share on other sites More sharing options...
L19MUD Posted August 13, 2012 Share Posted August 13, 2012 * typo - Calliper paint Quote Link to comment Share on other sites More sharing options...
Julian Posted August 13, 2012 Share Posted August 13, 2012 However, the corrosion seems to have mostly been at the base of the bleed nipple (how?) - the seat doesn't look like it'll ever seal cleanly again. Ho hum. I don't feel happy about trying to grind that clean, so I guess it's new caliper time. Preferably 2, I think (opinions?). And it can have new pads at the same time... It will be just fine, when you wind the nipple up tight you will get a seal or I'll eat my hat - been there many times. Stick it back, bleed the brakes and have an assistant press hard on the pedal while you check for leaks. If it is leak free then Bob's your uncle!! Quote Link to comment Share on other sites More sharing options...
nickr Posted August 13, 2012 Share Posted August 13, 2012 Success with the mig welder. For what its worth though just in case someone else has a similar problem without a mig. I had this a few years back. I found the tang of a smallish file tapped in gently gripped and got it out - better than extractors Quote Link to comment Share on other sites More sharing options...
PS_Bond Posted August 14, 2012 Author Share Posted August 14, 2012 FWIW, it was arc rather than MIG in this case - I can see a need for a MIG in the near future (doors will need some TLC and I can't weld that thin a section with arc very well). The corrosion on the seat has chewed a spare bleed nipple (BFI in trying to get it to seat); there's no evidence of the tip of the nipple making decent contact with the seat. In googling around, I've found some possible solutions: 1. A place that will repair calipers "from" £35 - plus shipping both ways. A single new caliper can be had for £40+VAT, so... 2. There are bleed nipple repair kits on the market - these seem to be more for stripped threads than damaged seats as such, but consist of a replacement (larger) screw-in seat + nipple. JustOffBase seems to have them: http://www.justoffba...9&category=-109 , most of the rest of the sources I've found are US based. At £69 this still doesn't equate well with the cost of replacement calipers. There's 6 inserts in the kit, so it might make sense for a club I suppose? (Added - it's actually British made - http://www.fraserbrowneng.co.uk/store/index.php?route=product/category&path=60 ; made in Scotland, but probably not from girders) 3. Seat recutting - there are suggestions of using a bored-out nipple as a guide, followed by either a drill ground to 135 degrees or a custom cutter. Interesting, but I'd probably want to tackle that with a 4 jaw chuck on a lathe. New Bearmach calipers are on the way, so if I decide to have a go at the last option I can do it at leisure (and mostly for interest, realisitcally). As for the paint... It's only to try and delay them getting quite so kakked up. Quote Link to comment Share on other sites More sharing options...
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