Few question on hydraulic brakes

Alston251

Hi all, just a few questions about hydraulic brakes.

Where can i buy the yellow Shimano brake spacer? My Deore 595 brakes didn't come with anything.
How do I know if my brakes are bled properly and cannot get any better?
How do I know if my brake pads are contaminated? Preferably without riding with them.
What is the preferred solution to clean disc brakes? Disc brake cleaner is rather expensive and I've read about it being really nasty. I've also read about using alcohol: some say isopropyl, some denatured, some 50/50 mix with water. Which one is best?

Thanks in advance

Anonymous

Clean your brakes generally with water. If the rotors have any grease on them, clean them with isopropyl alcohol. If the pads are contaminated, then, really, replace them.

explosifpete

Most bike shops will have loads of the yellow spacers as they come in the box with new brakes.
Does the lever have a firm positive feel rather than a spongy feel? Do they stop you?
Have a look at the pads as if they have become contaminated they go darker and shiny, I find a gentle scrape with a razor blade helps
halfords sell car disc brake cleaner for about half the price of the bike stuff and I think is just the same

cooldad

You don't really need it.
If they work well. If they are spongy they need bleeding.
You can't - if they don't work they might be contaminated. Never had the problem - I think it's an overhyped term. Don't get oil/grease etc near the brakes.
Water - hose/rinse after a ride - lots is good. You just need to get mud/sand/grit out.

Anonymous

explosifpete wrote:

Most bike shops will have loads of the yellow spacers as they come in the box with new brakes.
Does the lever have a firm positive feel rather than a spongy feel? Do they stop you?
Have a look at the pads as if they have become contaminated they go darker and shiny, I find a gentle scrape with a razor blade helps
halfords sell car disc brake cleaner for about half the price of the bike stuff and I think is just the same

After having some motorcycle disc brake cleaner turn my brake pads to mush on the mountain bike, I'd stay away from car/motorcycle brake cleaner, just in case. IPA works, and works very very well.

Alston251

Thanks for the quick replies so far.
I tried not to get my pads contaminated when i bled them after i cut the cables down.
But I'm asking just in case and to know what to look for.

My front brake is pretty solid but I can feel a difference in the rear. I know the rear is "less important" but I would like to know that will be able to perform the same. I'll probably bleed them again while using the bottom up method instead.

On a side note, my brakes seem to have poor modulation and multiple people who have ridden my bike has said that. I just to happened to have crashed on my first ride due to that too. I'm getting used to it now having done more riding. But is there anything I can do to improve the modulation?

Thanks a lot

Anonymous

The only thing you can do to improve the modulation is to reduce the size of the brake rotor, but that can possibly have unwanted side effects.
Also worth considering is that sintered pads are more "grabby" than organic resin ones.

Hopefully, in time, you'll adapt to the "feel" of the brake. Deores are extremely powerful, but generally have great modulation.

Alston251

Thanks for telling me now, I was thinking of getting 180mm front rotors to improve the power. But if that makes the modulation worse then I won't.
I think I have resin pads on since i got them with my brakes stock from Merlins.

Thanks

explosifpete

Confirming what Cooldad just said i've never really bothered with disc cleaner as it just seem to make the brake squeak for a while and thats about it

cooldad

Before you bleed the back, just make sure the pads aren't worn, or the pistons aren't too open - take the wheel out, squeeze the brakes a bit, lever the pads open just enough to fit the rotor back in and squeeze again.
This will adjust the pistons a bit. Sometimes they don't self adjust perfectly.

Shouldn't need to bleed brakes for years unless you introduce air in somehow - it's a closed system.

Anonymous

cooldad wrote:

Shouldn't need to bleed brakes for years unless you introduce air in somehow - it's a closed system.

Or boil the fluid - but then you really need to flush them, not bleed them if you've done that.