gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 12, 2011 18:35:45 GMT
I know a lot has been covered on this before... diversionclub.proboards.com/index.cgi?board=600&action=display&thread=2687 ... but I'm in the same position with a sheared bleed valve. Before I go down the path of trying to extract it myself I'll head to Yeovil with caliper in hand to try and find a workshop that might be able to extract it for me. In the mean time, if anyone has a rear caliper for sale could you please reply or PM me... I don't want this to draw out too much as I need the bike for commuting. Otherwise, can anyone suggest somewhere to buy one or an alternate fit caliper, if need be I'll go for a re-furbed item... ebay has nothing but caliper brackets and I've had no luck on google yet. The bike is a 1995 XJ600S. Thanks in advance, Gavin |
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Post by Flymo on Jul 12, 2011 22:16:46 GMT
you could try some heat and a reverse threaded stud extractor...
if it needs a rebuild anyway don't worry about melting the seals...
Flymo
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Post by sparky392 on Jul 12, 2011 23:05:05 GMT
Don't know if this helps, I had similar prob, I drilled sheared bleed nipple out, retapped and blocked with m6 bolt. then bought a banjo bleed nipple bolt from wemoto, cant remember how much it cost but am sure it were under a fiver, not had a problem since! (appx 2yrs ago now)
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 13, 2011 7:25:54 GMT
Thanks guys. I guess I could try both suggestions... if the extractor doesn't work just drill the bugger out and block the hole then get the banjo bleeder.
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Post by bobh on Jul 13, 2011 10:12:31 GMT
I did successfully drill out a bleed nipple in a D6 rear caliper and was able to re-use the hole for a new one. But you have to be ever so careful not to damage the seat in the caliper body.
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Post by peteff on Jul 13, 2011 10:29:23 GMT
If the old one's sheared and still blocking the hole why drill it out to put something else in it's place? The nipple seals on the bottom taper but a bolt will only seal on it's thread.
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 13, 2011 10:47:05 GMT
I did consider just leaving it as is, but I'd rather try to fix it properly first. If that fails by damaging the thread I'll figure something out from there. I've dropped it off at a workshop that Morgan's Motorcycles use for their brake rebuilds, hopefully they can sort it out... I'll find out later this afternoon or tomorrow.
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Post by amorti on Jul 13, 2011 10:47:32 GMT
If the old one's sheared and still blocking the hole why drill it out to put something else in it's place? The nipple seals on the bottom taper but a bolt will only seal on it's thread. +1 as above, leave it in place, and either bleed with one nipple (it's perfectly possible) or replace with a bleed-nipple banjo. Easy. |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 13, 2011 11:11:13 GMT
Now I'm doubting myself. It might be best if I call the workshop and just get them to extract the pistons and go the banjo bleeder. The other bleed nipple doesn't look any better... I don't think I'll even attempt to remove it!
Thanks all for your feedback
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Post by amorti on Jul 13, 2011 11:46:21 GMT
Now I'm doubting myself. It might be best if I call the workshop and just get them to extract the pistons and go the banjo bleeder. The other bleed nipple doesn't look any better... I don't think I'll even attempt to remove it! Thanks all for your feedback Might as well have a go. The worst that happens is it's already broken and you snap it, in which case you still need the banjo bleeder. Well actually I guess the worst that happens is it snaps off and you end up with it leaking. Hmm. But I think it's rare to get it moving and then snap? Boys and Girls - this thread is another timely reminder to ensure you have rubber covers on any and all bleed nipples. They seize because water gets in through the top, yanno. |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 13, 2011 12:38:09 GMT
Further to your tip on the nipple covers, would a tiny amount of copper or rubber grease on the thread of the nipple help prevent the corrosion between the steel nipple and the aluminium (?) caliper?
I guess if the brakes were tended to with any frequency, and with due care, by previous owners I wouldn't have this problem now.
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Post by amorti on Jul 14, 2011 9:03:34 GMT
I think you would - if anything - be better to apply a little PTFE tape. But sure, copper grease couldn't hurt in that application.
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 14, 2011 9:08:50 GMT
Hopefully I'll hear back by lunch time on my caliper. I've told them not to remove the sheared nipple, just to extract the pistons for me. Hopefully the pistons and caliper internals are free from corrosion/scoring. If they're no good maybe the calipers Dave has for sale will suit my bike. As far as I can tell, the part number for a new rear caliper is the same for a 92 600 S and a 95 model...
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Post by amorti on Jul 14, 2011 10:12:21 GMT
They are the same for all years.
You can rescue surprisingly bad calipers, but yes there is a point where corrosion wins.
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 15, 2011 11:39:21 GMT
I've got the caliper stripped down, ended up doing it myself as the workshop was messing me around. The caliper is in good nick, I've got new rear pistons and seals, banjo bleeder (if I decide to use it), and new pads on order... hopefully it will arrive tomorrow or Monday for the rebuild. While I'm at it I'll put new seals and pads on the front.
Hopefully the bleed won't be too tricky as the sheared nipple is on the wheel side of the caliper- so I've got to encourage the air back to the outer side with the serviceable bleed nipple and/or banjo bleeder (the other nipple came out nice and easy, I wish I picked that one to crack open in the first place!). I have a cunning plan for limiting the air on the inside with the sheared nipple... I'll let you know how I go.
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Post by showaddydadito on Jul 15, 2011 13:14:38 GMT
I've been psyching myself up to do a caliper overhaul this weekend. First time I'll have been inside any brakes since about 1976. This thread is keeping me awake at night.
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 15, 2011 13:50:14 GMT
Well, as long as you learn from my mistakes  Before you touch your bleed nipples inspect around the base of them first, look for signs of corrosion that could lead to the problems I've had. I was very cautious with the second bleed nipple... soaked in some WD40 around the base of it then with a socket started of by gently bumping the handle and progressively increased it (without putting enough effort to actually turn the nipple). My theory was that it might coax any corrosion to give a little before I put the turns on it... it came out easily. Maybe it wasn't as bad as the other, maybe the WD40 and gentle tapping helped loosen it... either way, at least I don't have two broken bleed nipples! Depending on the condition of the seals, getting the rear pistons out can be a bit tricky as they are opposite each other... I managed to get them both almost all the way out, but they wouldn't both come out at the same time... they also didn't want to go back in because of the seals jamming the pistons. The pistons eventually came out with a lot of cursing and a set of multi grips  (hence the new pistons on order  ). Front ones should come out easy enough... just pull the pads out and squeeze the brake lever until they fall out (onto something soft!). Good luck with your brakes this weekend! |
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Post by bobh on Jul 15, 2011 21:45:57 GMT
The trick to getting the pistons out of the rear caliper, and any caliper with opposing pistons, is to push out one piston at a time (hydraulically) with the other(s) clamped right back, pick out the dust seal, which is usually the cause of it sticking, put it back in and repeat until all pistons are free. Obviously you have to hold the caliper in such a way that the piston you are pushing out is pointing upwards so you don't lose any (or too much) fluid.
Having done that you can take the caliper off and blow the pistons out easily with a tyre pump , or remove them with soft-jawed pliers.
I've just successfuly overhauled the blue-spot calipers from my Thundercat using that method.
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Post by teejayexc on Jul 15, 2011 21:56:31 GMT
Having done that you can take the caliper off and blow the pistons out easily with a tyre pump , or remove them with soft-jawed pliers. Or for the really stubborn bast*ards, unscrew the bleed nipple and refit a normal grease nipple, block the brakeline hole and stick a grease gun on the grease nipple. Pumps them out as soft as sh1t ! Oh, I wish we had a TIPS section for moments like this  |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 16, 2011 7:44:21 GMT
The trick to getting the pistons out of the rear caliper, and any caliper with opposing pistons, is to push out one piston at a time (hydraulically) with the other(s) clamped right back, pick out the dust seal, which is usually the cause of it sticking, put it back in and repeat until all pistons are free. . Yep, that was my plan except I couldn't get either piston back in far enough to allow the other out due to the seals jamming the piston. To assist in getting one piston retracted I went for the bleed nipple to remove pressure behind it... that's when it sheared. Even with the caliper off the bike using a clamp I had a bugger of a time getting the piston back in. |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 16, 2011 7:46:29 GMT
Or for the really stubborn bast*ards, unscrew the bleed nipple and refit a normal grease nipple, block the brakeline hole and stick a grease gun on the grease nipple. Pumps them out as soft as sh1t ! Worth keeping in mind, that would still work even with one sheared nipple... |
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Post by m40man on Jul 16, 2011 8:53:53 GMT
.... Even with the caliper off the bike using a clamp I had a burger of a time getting the piston back in. This means you haven't resolved your problem. With thumbs applying even pressure each side of the piston, it should push in quite easily. So it looks lke you need to re-do, making a better job of cleaning any crud from under the seals. But the seals themselves often have tough crud adhering to them. This doesn't mean you need new seals though. You can pick of the crud with a fingernail or quicker & easier scrape it off with a smooth blade (I find MrsM40Man's vegetable knife works well  ) & re-use the seal unless you find splits in it. You'll know you've done an adequate job when the piston pops back in nicely. |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 16, 2011 9:26:28 GMT
.... Even with the caliper off the bike using a clamp I had a burger of a time getting the piston back in. This means you haven't resolved your problem. With thumbs applying even pressure each side of the piston, it should push in quite easily. So it looks lke you need to re-do, making a better job of cleaning any crud from under the seals. But the seals themselves often have tough crud adhering to them. This doesn't mean you need new seals though. You can pick of the crud with a fingernail or quicker & easier scrape it off with a smooth blade (I find MrsM40Man's vegetable knife works well ) & re-use the seal unless you find splits in it. You'll know you've done an adequate job when the piston pops back in nicely. I wasn't clear... I was talking about getting one piston in fully so I could remove one then the other. I'm still waiting for the new seals and pistons to do the rebuild. I've been working hard on getting the recesses for the seals as clean as possible so there is no protrusion that will lead to the seal getting jammed again. I'm going to see if I've got a suitable screwdriver (one of those little silver ones) for sacrifice... bend it at 90 degrees near the tip and have it scrape smoothly all the way around to clear gunge. |
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Post by m40man on Jul 16, 2011 10:03:00 GMT
..I wasn't clear... I was talking about getting one piston in fully so I could remove one then the other. I'm still waiting for the new seals and pistons to do the rebuild. Ahh, my bad. That's alright then . I should be attending to my rear D9 rear caliper but rain has stopped play . |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 16, 2011 10:08:14 GMT
Just finished cleaning the caliper properly... I found using a small hex key worked nicely to clean all the way around. It's about as good as it'll ever get... just need my parts now. Back to the window to wait for Postman Pat  |
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Post by teejayexc on Jul 16, 2011 12:41:51 GMT
Just finished cleaning the caliper properly... I found using a small hex key worked nicely to clean all the way around. It's about as good as it'll ever get... just need my parts now. Back to the window to wait for Postman Pat Hex key will never get into the edges of the crevice, (ooh I like that word), best tools are a dentist pick, preferably plastic, or better still a dremel (other makes are available) and a small brass wire wheel on it One for the TOOLS section? |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 16, 2011 13:43:58 GMT
Agree with hex key not reaching the edges, I'm using a 1mm hex key for the bulk of it, but still reverting to the smallest screwdriver I have (~0.5mm tip) for the corners. It seems to be ok, but I agree a dentist's tool or a dremel would do a much better job... especially the circular wire brush.
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Post by bobh on Jul 16, 2011 17:10:32 GMT
I have a selection of bent and sharpened bicycle spokes that seem to do the job OK. As M40man will attest, there is no shortage of these (with or without bicycle wheels) in my "workshop".
I guess a Dremel would be quicker, though.
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Post by DahDit on Jul 16, 2011 17:32:32 GMT
One for the TOOLS section? You should reside there |
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gacf
Harley Rider
Posts: 80
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Post by gacf on Jul 19, 2011 13:17:18 GMT
Finally my saga is at an end... well pretty much. The front caliper assembly went nice and smooth, the rear caliper was a bit trickier... the pistons were reluctant to go in but were eventually persuaded to. The rear caliper is being stubborn bleeding all the air out, but it finally feels ok and I'm just bedding the pads into the disk now. The rear pads do seem to be dragging a little bit so after a few miles I'll pull the pads and spring out and re-grease the edges... I think a bit of grease was lost fiddling around with the pads to get the bolts through. It's back on the road now and stopping better than before and I expect it will get a little better as the pads settle in. Thanks all for your help and advice... stay tuned for my next saga- when I attempt to remove the tatty looking sump plug for an oil change |
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(hence the new pistons on order 
). Front ones should come out easy enough... just pull the pads out and squeeze the brake lever until they fall out (onto something soft!). 
) & re-use the seal unless you find splits in it. You'll know you've done an adequate job when the piston pops back in nicely.
