You are hereForums / By Discipline / Mountain (off road) / MTB Gear / Hydraulic Disc Brakes - Problem
Hydraulic Disc Brakes - Problem
Yesterday I received my disc brakes from CRC. A set of Avid Elixir 3.
I think there may be a problem with the pistons or pads?? There is very little room between the pads on the rear calliper. The wheel side pad/piston doesn't seem to fully open and I cannot get the calliper aligned so the pads dont rub on the rotor(even with he Avid CPS system).
Earlier when I was installing the brakes and went to remove the rear pad block/spacer, it wouldn't come out easy. Was jammed. I had to pull hard to remove it. The lever was still in bubble wrap and had NOT been pulled.
Does it sound like a problem with the wheel side piston? Can they be realigned? Do I need to bleed the brakes to realign?
I have contacted CRC but thought someone on the forum might offer advice faster.
Thanks.
- Login to post comments
- Bookmark & share
Are the pistons flush with the calipers, or even retracted slightly.? I had a similar issue with Elixir 5s when changing pads.
I might need to have a closer look to see exactly where the pistons are (flush, partially retracted etc). The wheelside pad wont fully retract/open even if I carefully try to push it over. So I assume the piston mustn't be fully retracted?? But dont know for sure.
I had to really put some pressure on mine to open them up. I put the olds pads back in for protection and used a large flat blade screw driver to lever them open.
Thanks. Will try that tonight. DOnt have old pads but will use something softer than a screwdriver. Maybe a tyre lever.
Not.
It sounds very much like the brakes are over, or very, full of fluid. I've come against a similar issue when bleeding Elixir CRs with worn pads, then tried fitting new pads a short time later. I know, I know..... always remove the pads and fit a spacer block blah blah blah... anyway, bleeding off a little fluid at the caliper by cracking the bleed screw and pushing back on the pads/pistons at the same time seemed to work for me.
One would like to think that Avid had the process down pat, and they could fill and bleed a new set of brakes perfectly, every time.
Do you need to adjust
cablehose length? If so I'd suggest waiting until that was done then bleeding the system from scratch if you have time on your side.I actually got really lucky and the hose length is OK. But not perfect.
I will probably shorten the hose slightly in the future. But if I have to let a little fluid out to push the pads/pistons back, I will take your advice and also shorten the hose at the same time and do a full bleed (with spacer/block in.
Just waiting for the bleed kit to arrive.
I hope you got an amazing deal. Especially since the excellent XT brakes should be close to $100 each.
I always had problems with my avid brakes. Spent an hour each end de-gassing brake fluid, flushing, bleeding, changing pads, and after 5min they were spongy again and squealed like hell. Even the bike shop couldn't do any better. Did each end ~5 times over 3 months before I gave up.
XT's ran maintenance free for the year I had them until I sold the bike. XTR's have been hassle free to install and zero maintenance for 6 months so far.
As for the problem... I was also going to suggest opening the lever bleed screw, then pushing the pistons apart. Ideally you should be able to pull the lever and have both pistons move together, and be able to push both back apart. If one is sticking more, id think there was a problem.
I don't know what the CPS system is, but when I installed the XTR's, I just grabbed a fist full of brake (with the wheel and disc installed), held it and tightened the calliper bolts. When I let go and spun the wheel everything was perfect.
Thanks Mr Mez. I managed to track down an Avid setup guide here http://www.evanscycles.com/product_document/file...
And it says to do exactly wot u recommended (open bleed screw and push pads/pistons apart to remove excess dot fluid).
I think I got a good deal on the brakes. $42 each.
CPS is Avids mounting system that uses ball washers (??) to align the calliper on a 3d axis instead of just left/right. In theory it looks great, but I am yet to see it Actually work properly coz of my piston issue.
Well, I tried several times to advance the pads as per the SRAM brake setup guide. It definately got the pads/pistons all the way open (retracted). But everytime I pull the lever, the wheel side piston will close but not fully retract. It is left rubbing on the rotor.
Then I tried the next suggestion in the setup guide (and as suggested by forum members above). Opening the bleed port and letting a little DOT fluid out while retracting the pistons using the spacer/block.
Wheelside piston still not behaving.
The only good news I have is that CRC are sending me a new rear brake for free. A pity they have such slow postage to Oz. But I do get to keep the malfunctioning brake. So I end up with spare pads and parts. Yay.
So today I have learnt that Avid brakes suck.... and CRC have great customer service (as always).
Try a dab of copaslip on they piston that sticks. Not too much and be careful not to contaminate the pads.
Avids tend to squeal even when set up perfectly. There's a reason they were cheap. Having said that I had a rock hopper that had juicy 3sl and pace rc303 with juicy 5s and never had trouble.
Now running Formula and absolutely love them.
Oh and crc slow? 3 to 4 days to me. Quicker than ordering stuff from over east! And cheaper...
Thanks aphex2k
Where can I get copaslip? And approx how much is it?
I ended up getting a replacement. They sent it DHL express and got it I. 5 days. I used to always get stuff in 4-5 days but the last 10 orders have taken nearly 20 days each. Very frustrating. I think sometimes u can get lucky and they send it DHL express for free.