Quesiton on hydraulic disc brakes

DePurpereWolf

I recently drove over a 2 inch nail which skewered my tyre. I have Schwalbe Marathon tyres, which are great for the glass shard covered roads of Cork, but nails are a bit too much.

When I replaced said tyre, I must have inadvertently touched the brake lever and so my brake pads were out of alignment. I have hardly any experience with hydraulic disc brakes. I think I fixed it, but now there doesn't seem to be any pressure on the pads, some oil had come out and I think there isn't enough oil in the reservoir to build up pressure.

Can I just get some hydraulic disc brake oil and top up the reservoir? Or is it more complicated than that. So, add a bit of oil, wait, screw the reservoir cover back on and try to see if it works. If not, repeat?

I have these brakes: http://www.shimano.com/publish/content/global_cycle/en/us/index/products/0/alfine/product.-code-BR-S500.-type-..html

Whitehawk

Are the pads locked together? as if you hit the brake and there is no disc in this happens and you need to unlock them, few vids on you tube on how to do it, even something like this vid may do - http://www.youtube.com/watch?v=E-xe5SurfME

If not this and seen as some fluid did come out maby some air got in i have no exp in this area but when getting my first hydraulic disc brakes i did look in to it and from what i know you need something like this Shimano Bleed Kit & Oil so that you can add in some new brake fluid and get rid of air or what ever is messing up brakes

After that im not to sure what else it could be! even just takeing out the pads on the brake and putting them back in may do the job!
best of luck with it tho.

Icyseanfitz

if oil got out you will have to bleed them, you need to get a bleed kit for whatever type of brakes you've got, but if oil escaped you may have to check your pads and rotor to make sure no oil got on them as they wont work correctly if it did,
you would nearly be better off going to a lbs to get it sorted as hydraulic disk brakes can be a real pain in the arse to fix

Ricky91t

I'd agree with Icyseanfitz, I recently replaced mechanical disk brakes to Hydraulic disk brakes(hayes HFX9's) and it wasn't easy. Saying that the hayes bleeding kit isn't meant to be very good and in the end I went into the local vets and got a 30ML syringe.

These brakes were completely empty and it took me 2( I put the bike back in the shed the first time after getting covered in brake fluid) attempts to get them working, First with the filler bottle hayes recommends and second with the syringe. It's all very easy filling the cylinder with DOT4 fluid(I think Shimanos use that) but getting the bubbles out of the system is tough as this give the leavers a 'spongy' feeling when braking.

Saying that, once you've done it once, you'll know what to do the next time and as long as you have the kit available you could easily get it done in 30 minutes and although it's not a very regular thing to do I was charged €30 to set up my breaks before so I'd rather do it myself :pac:

kona

Did the pistons come out? Shimano are a piece of pish to bleed, you only need basically abit of tubing and some mineral Brake fluid. DONT USE DOT.4 or .5

If the pistons are still in just open the reservoir and lever the pistons back into postition.

boomdocker

it's easy....bring them to your local bike shop.....

if you are inexperienced in these things better to let an expert do it. an experienced bike mechanic will fix that in 10 mins for about €25...

langdang

Ricky91t wrote: »

I'd agree with Icyseanfitz, I recently replaced mechanical disk brakes to Hydraulic disk brakes(hayes HFX9's)

I've had em on two bikes - took me a few goes too. Still using em on one bike. I'm guessing you got them cheepcheep (they have a lot of bad reports online), but they're grand brakes unless you get a troublesome set.

GTDolanator

ok where did oil/fluid come from?cause it shouldnt have leaked at all,not unless the pistons popped out.what brakes are they?

Lemag

GTDolanator wrote: »

ok where did oil/fluid come from?cause it shouldnt have leaked at all,not unless the pistons popped out.what brakes are they?

If I were to hazzard a guess it'd be that the OP inadvertently loosened the bleed nipple.

Only thing for it OP is to bring it to a shop. I'd suggest bringing it to an mtb specialist shop as they'd be more likely to do a better job. Noone likes spongy brakes.

DePurpereWolf

I opened up the top reservoir to push back in the pistons, as I believe to have read somewhere that that's the thing to do.
After talking to my lbs the whole bleeding shouldn't be such an ordeal as some make it out to be. It's my rear brake so I'm not adverse to giving it a try. I don't think I can do much harm in trying to add oil to the reservoir and bleeding the air out.

I did it last winter with my heater when I ran out of oil ...