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My "summer bike" has been stored all winter standing upright against a wall. When I came to get it out for summer, the front brake lever was soft and there was a pool of fluid underneath the bike. It is the old-style Hope M4 (black and gold variety).
The reservoir was empty, so I refilled and bled it. After a test ride, there was fluid again trickling across the caliper, so I did the bleed nipple so tight I almost sheared it off. Still a trickle coming out and the brake feels really weak.
Could this be the seals gone? If it is, my (inexpert) opinion is that changing seals is a harder job than repairing an expensive Swiss watch drunk with a sledgehammer blind-folded and with one arm tied up while being attacked by a crazed Alsatian called Thor (or something equally manly). But it could be that I am exaggerating the difficulty in my head!
Any thoughts as to what the problem might be and whether it is worth trying to fix at home, or make the long trek to the nearest LBS that I would trust?
drunk with a sledgehammer blind-folded and with one arm tied up while being attacked by a crazed Alsatian called Thor
Yup, I reckon you could easily do it under those circumstances, in fact - I reckon the dog could do it
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Does sound like the piston seals are shot?
Give hope an email and piccy and see what they say - they are very very helpful 🙂
You'll need the bore cap tool, but it really is quite an easy job. A bit fiddly on the M4, but still pretty simple. Here's a [url= http://steveukmtb.wordpress.com/hope-caliper-overhaul-minitrialsm4v2m6/ ]photo guide[/url] that I put together.
Make sure that it's not just a loose fitting first, though.
Can you actually see where the oil's leaking from?
I would've thought it's most likely to be the seals, although it could also be leaking around the banjo/hose joint. Can't think of any other other parts that would deteriorate to cause a leak.
M4 seals are pretty easy to replace.
If you're unsure the Hope website & tech support guys are very helpful.
I did try Hope actually (admittedly no piccy) and they suggested I try my LBS (job too small for them, which gave me some "hope" that I could tackle it myself, against my better judgement).
I've also found a packet of spare seals floating around, which gave me a rush of ridiculously excessive over-confidence in my pathetically bad skills.
I would've thought it's most likely to be the seals, although it could also be leaking around the banjo/hose joint. Can't think of any other other parts that would deteriorate to cause a leak.
+1
Cheers everyone. I can't see for sure - it seemed to be the bleed nipple but I don't think it is. Will tighten the fitting again as well - good call.
Thanks for the guide. I will think hard about this......
BTW if you overtighten the bleed nipple the washers will be crushed and may make it leak worse? Go steady 🙂
REPLACING SEALS IS FAIRLY STRAIGHTFORWARD - BUT HOPE DO A REBUILD SERVICE THAT IS VERY CHEAP -
apologies - caps lock
Thanks again. Three Fish, that guide is brilliant!