rear disk brake help

Icyseanfitz

hey guys im fairly new to the whole biking scene and im a bit worried about the rear brake on my mtb its a avid juicy 3 hydraulic disk brake and its making a small squeaking noise every time i move the bike forward, im thinking i might have lost one of the brake pads for the disk as i can only see one whereas i think there should be two (are these expensive to buy?), also does anyone know a good reliable bike shop in kerry where i could take my bike to get serviced as i think the rear derrailleur isnt working correctly at the moment

Greyspoke

To check if you still have both pads, take the wheel out and turn the bike upside down and have a look - it should be much easier to see that way. It'd be unusual for one to fall out as they're usually held in by some form of pin and also a flimsy spring clip that keeps the two pads apart. If you do still have both pads, put the wheel back in and spin it to see if it runs freely - if it does and there's still the squeeky noise, I shouldn't worry too much as a slight bit of pad rub is quite common and not really a problem. There is also the possibility that the disc itself is slightly bent or warped - again you can see if this is the case by spinning the wheel slowly and looking directly down at the caliper where you'll be able to see any side to side movement. It can usually be quite easily fixed by carefully bending it with an adjustable spanner or pliers - just do it little by little and be careful.
Replacement pads aren't too expensive, perhaps 15-25eu. Make sure you get the correct pattern.
Sorry can't advise on Kerry bike shops!

CheGuedara

+1 On what Greyspoke says - get the wheel off, make sure all the pads and clips are present and if they're still squeaking you could be looking at a warped rotor or contaminants on the surface (MucOff do a good disc brake cleaner if you want to try it. Making sure that the wheel is reinstalled properly and the quick releases correctly closed should help things also. At the same time so long as the brakes are doing their job I wouldn't unduly worry about it.

Re. Kerry bike shops - only place in Tralee that would be allowed near any of my bikes is O'Hallorans in Boherbee and if based in Killarney 'The Big Little Bike Shop' on Woodlawn Rd. Both owners know their stuff.

Icyseanfitz

thanks for all the help guys im pretty sure im missing a rear pad il put some photos up so ye can have a look (there is meant to be two pads in the rear right?).
is O'Hallorans the gas supply shop next to the veterinary and the charity shop? i live in Tralee so it would be great if they know their stuff down there so i can get the bike serviced(although my bike is a little different than a normal mtb because it has bionicon's on the fly suspension system hopefully that wont be a major servicing problem )
the two pics are of the rear disk brake

langdang

Yup, that's missing a pad.

Icyseanfitz

suppose i better stop riding it till i get one then these are what i should be looking at right? whats the difference between organic and sintered pads?

Biopace

Looking at the pic the piston itself has come right over to rest against the opposite pad, watch out that no fluid is leaking from around the piston, if it has you will need to bleed out the brake and put in new fluid, a tricky enough job with Juicy 3's requiring a special kit.

As regards sintered vs organic, I'd go with sintered for better wear.

Icyseanfitz

crap a bike shop would be able to help with that right? i was wondering why the piston was out so far

Icyseanfitz

Biopace wrote: »

Looking at the pic the piston itself has come right over to rest against the opposite pad, watch out that no fluid is leaking from around the piston, if it has you will need to bleed out the brake and put in new fluid, a tricky enough job with Juicy 3's requiring a special kit.

As regards sintered vs organic, I'd go with sintered for better wear.

i cant find any fluid escaping and i also have brake pressure (the brakes work just not as well as with a pad)

Single Malt

The piston may need replacing, it usually gets damaged touching the rotor if the bike was used in this way.

Icyseanfitz

well i only used the bike this morning without the pad (i know i had two yesterday or the day before) so there shouldnt be too much damage (hopefully) out of interest how much is a new piston?

Single Malt

It only takes one brake activation for the piston to touch the moving rotor. This damages the pad retaining protrusion, and the piston will not hold a pad in place.

Icyseanfitz

well arse any idea how much total this is going to cost to fix? im better off just buying a new rear brake system?