I was experiencing a spongy rear mini mono, so I tried bleeding it repeatedly, but was getting no power from it. When fluid started leaking from it, I took it to my LBS who fitted and serviced it with a new seal kit.
I made the school boy error of spinning the rear wheel, pulled the brake lever and the wheel stopped. Job done. Fast forward one day and tested the brake whilst actually riding the bike (lesson learned), in the Glen Tress car park and it still has a spongy feel. If I fisted the brake it would stop, but nothing like I was expecting or my front brake.
The obvious answer would be to return the bike to the LBS, but is there anything I should consider first? Can the new seals take time to bed in, does the brake need pumped more or left overnight with the lever closed? The bike had sat for a few days before it was collected.
I think the shop had missed adjusting the caliper too, so did a little trail adjustment to help things runs smoother, but still only getting 7-8 revolutions before the wheel turns to a halt. I need to look at that properly and perhaps fit another spacer to imporve adjustment.
The mini mono's replaced Avid Juicy's. The power and feel of my front brake is fantastic, I just wish I could get the rear to perform similarly.
Sounds like they just need another bleed, possibly some air trapped from the service. For a quick fix.... zip tie/elastic band the lever to the bar overnight, remove the top cap and top the fluid up in the morning.
what mike said.
chances are if you have got used pads in there the pistons have been pushed all the way back in when they have been bled. so when you pumped them up thefluid level would drop. then if the bike has been in the car air from the top of the resv has moved in to the system.
brake bleeding: best done yourself imho.
what you want from the shop: someone experienced, who'll take the time to make sure it's done well, for £10 or less.
what you'll get for £10: the trainee for half an hour.
All of the above. My experience with brakes: DIY or send to Hope.
the above is what i would have advised too....also check that the bite point on the lever has not been altered...unwinding this out could also make the lever feel mushy
Thanks for the responses. At least I know the seals are new. I think I will tie off the lever overnight and then top up the reservoir first.
The next time I bleed, I will also ensure I have a mate standing by to check the resevoir levels. A bit tricky to do when bleeding the rear brake.
It is a shame you cannot loosen off the caliper and re-tighten at the bite point, like other brakes to centre it though.
there are videos on youtube showing you how to achieve 'centring'
if they arent truly central then you will get sponginess...although once they are centred, they are excellent
It is a shame you cannot loosen off the caliper and re-tighten at the bite point, like other brakes to centre it though.
Worth a try, sometimes it works, but I don't think it would fix your current issue.
They are really good those you tube videos. Although I can understand why he chose to bleed the front brake single-handed.
The caliper adjustment is a secondary issue, but the video shows that it is easier to do than described. Still a bit of a faff, but once done, looking forward to having excellent brakes again.
I persevered with hopes for years, in fact I still have some mono m4 on my 29r, and am underwhelmed with them.
They don't hold a candle to the xt brakes on my other bikes
I am always tinkering and messing with the hope set up, the xt are just fit and forget for me, pull the lever and stop.
I know that's not what you asked, but
I had trouble bleeding my rear Hope brake. I took it to the LBS who bled it, felt so much better.
He explained that due to the frame design, the bleed nipple is at the lowest point. So you have to remove the rear caliper so it's at the top.
Milkie
nipple at the lowest point - doesn't really make any difference.
you are pumping the fluid through using the lever. you should be pushing all the air out.
Bleeding hopes (as many others) is a easy process to do but there is a knack to doing 100% right.
I'd recommend you keep going until you have 100% clean fluid coming through then do a bit more.
the hope vids are good and its defo worth rolling the diaphram on as per vid.
what levers you got on the bike
Hope Tech Levers if not bleed correct can hide a few cheeky air bubbles in the master cylinder
you have to do the normal bleed then rotate the lever as to get any air trapped in the master cylinder out
http://www.youtube.com/embed/QzGQpS6fd3E
http://www.youtube.com/embed/8LPd_cpZ6KU
ps, does any one know how easy it is to strip down and rebuild a tech lever , my rear lever is slowing dying and needs some tlc and new seals I think