[Mike the bike]

This is the first time I'm bleeding my brakes (or any hydraulic brakes for that matter), I have only recently bought the bike second had off a friend and he'd always take it into the shop to get done.. but I'd like to do it myself.

I'm just wondering what are the best tools and d.o.t. fluid to use.

I mean should I bother buying a "Hayes Pro Bleed Kit"
or should I just use a syringe with a hose?
and is the Hayes d.o.t. 4 the best fluid to use?

thanks in advance

 

[sanjuro]

At the shop, we use an industrial syringe, hose, bottle, and a derailleur ferrule with a tip, cut diagonally.

After you cut the tip diagonally, you can screw that end into the bleed port on the lever.

We use just auto DOT fluid.

 

[Mike the bike]

I attempted my first bleed earlier tonight, regular d.o.t. 4 auto fluid and a syringe with a hose,
the method I was told by my friend was to attach the hose to the hydraulic point on the calliper(loosen it slightly first) and push the fluid from the syringe up the cable filling the master cylinder then re-attach the master cylinder cap and pop the bleed cap back.
is this correct?

 

[sanjuro]

Except where does the excess fluid go? All over your bike?

That's what's the bottle is for, to catch the overflow. The Hayes kit (which I just bought) has a screw-in adaptor.

You can even order just the adaptor.

 

[zebrahum]

The hayes pro kit isn't amazing, I think the regular old kit is sufficient. I would add a syringe in place of the squeeze bottle if anything and that makes it nicer than the pro kit.

 

[Mike the bike]

thanks for your advice I'm going to order the kit tonight as I have to get some more bits anyway.

also I don't like my brakes to be overly responsive I like to have a bit of room in my lever not to much that I'm pulling it to the bar though but enough room so I don't lock up my wheel straight away, what's the best method for achieving this?

 

[Mike the bike]

@ zebrahum
thanks for chiming in it's always nice to get a few different opinions.

p.s. i had a bit of a laugh when i seen you location with my tired eyes it looked like
it said Slut.
SL,UT

 

[zebrahum]

I suppose you could say it was intentional... because it was You could play with the amount of fluid you put into the system to adjust the pad contact, but I would reccomend trying to play with the 2mm reach adjusting screw that is hidden in the hinge near the grip on the lever. While it actually adjusts the reach, it makes a huge difference in the feel of the lever.

 

[sanjuro]

thanks for your advice I'm going to order the kit tonight as I have to get some more bits anyway.

also I don't like my brakes to be overly responsive I like to have a bit of room in my lever not to much that I'm pulling it to the bar though but enough room so I don't lock up my wheel straight away, what's the best method for achieving this?

Adjust the throw.

Can't really do it with the bleed.

 

[Mike the bike]

After the first bleed.. the next morning the front brake was just about non responsive
the back was a bit soft but worked. but i had to ride to work and by the time i got there
they were both to soft and couldn't stop (had to use my foot in the back wheel)

so what do you guys think i might have done wrong.. air in the line? or something more serious.

I have the bleed kit coming and it should be here tomorrow.

thanks for the advice guys

 

[jbro]

When i had my brakes setup slack, after i bled them i would put 2 business cards between the pads and the caliper.

Loosen the caliper, stick the business cards inbetween the rotor and caliper. Squeeze the hell out of the lever, hold pressure on the lever while you tighten the caliper. make adjustments by using less/more business cards.

 

[Mike the bike]

When i had my brakes setup slack, after i bled them i would put 2 business cards between the pads and the caliper.

Loosen the caliper, stick the business cards inbetween the rotor and caliper. Squeeze the hell out of the lever, hold pressure on the lever while you tighten the caliper. make adjustments by using less/more business cards.

Great idea

hey i was reading this thread on bikeforums.net and it says to use the bleed method reversed.

http://www.bikeforums.net/archive/index.php/t-118797.html

1) Filled syringe by drawing fluid into it from the can.
2) Pointed the syringe vertically and shot a little fluid out so that we had no air in the line
3) Attached a hose to the bleed fitting on the caliper and stuck the other end in a can with a piece of wire taped to the side-- hung the can from the rear stay.
4) Attached the syringe to the bladder at the brake handle.
5) Put some pressure on the syringe
6) Opened the bleed fitting on the caliper
7) Pumped brake lever at a normal rate until all air was out of line-- no bubbles coming out.
8) Closed bleed fitting.
9) Removed hose, replaced plastic plug-- what a stupid design!
10) Tried it-- worked perfect-- better than from the factory.

 

[zebrahum]

My theory is air bubbles float up, so make the lever the highest point and push the bubbles up and out, the way they want to go. I don't see any point in running the bleed that way.

 

[Mike the bike]

yeah that's a good point.

I'll give it another go tomorrow night.

 

[Mike the bike]

ok front are working fine, got a bit of contamination but nothing you couldnt put up with
but the rear keeps loosing it's fluid from the master cylinder, both of the torx screws wont tighten up at all so the fluid slowly seeps out.

i don't want to spend the money on a new master cylinder and screws because i think the thread in the cylinder body might be ... screwed

has anyone re-tapped these and put a different screw into them before?

 

[zebrahum]

I suppose it's better than doing nothing, but it doesn't seem like it is is likely to work. Do you mean the screws that hold down the reservoir cover? I would make sure that the rubber seal is in good shape all around, but it sounds like you stripped the bolts.

 

[Mike the bike]

Yeah it's the 2 screws that hold that in my friend did the first bleed on them and
one of the screws was already stripped so I had to use a different screw with a longer thread.
I never though they'd be that weak.. but when I got the bike the rear brakes were dry. so think it might have happened before me.
I didn't tighten them any more than the front one's and there fine.

man I'm really starting to hate hydraulic brakes

should have just bought a new bike, A wise man once said
"If you buy second hand goods, you buy other peoples problems"

 

[cycleguru]

Of all the different brakes I've bled the Hayes are probably the easiest. If you can swing the Hayes bleed kit you should because it has all the stuff (ie. fittings) you will need. You can scrounge around and find hoses, syringe, etc., but the only thing you probably can't find is the fitting that goes into the little rubber fluid exit port on the lever. Without this the old fluid you push through the system will just gurgle out the lever and make a big mess all over the place rather than being directed into your catch-bottle.

Also, Hayes DOT4 is the best, but any DOT4 will work.

 

[cycleguru]

OK. so I didn't read all the replies to your original question before I threw in my two cents worth. Sounds like you have the basic bleed proceedure down pretty well. However you did mention that you were having a problem with the brake (rear, I think) getting gradually weaker as you use it. This could mean that the inner wall of the brake line has a break in it (fairly common in old brake line) and needs to be replaced. Your local shop should be able to get you the right hose kit from Hayes.

 

[cycleguru]

I should have explained that when the hose's inner wall gets a break in it the fluid escapes into the space between the walls when you squeeze the lever causing the caliper to fail to close against the rotor. In other words "it don't work no mo"!

 

[Mike the bike]

update: I re-tapped the thread that holds the master cylinder cover and rubber seal on
I'm quite happy with the job as it feels a lot stronger and doesn't feel weak like the original thread.
I used a 4mm thread as the original thread is 3mm and I didn't want to re-tap it only to come lose again.
I can imagine it sounds like a butcher job but it was either do that or spend €30 on a new one this is something I'll do eventually but for now I have working back brakes
The first hole was a dream to tap but the second one closest to the bleed plug is a bitch
as you don't have much room to get the tapper in to make a thread as it's a short hole.
also i have a new Love.... Hope - Sh1t Shifter, I gave my bike a good clean after bleeding my brakes and I can't hear any squeaks out of them (I also use isopropyl alcohol on the brake leavers, calliper's and rotors).

I still think my brakes could be better though so am going to get a guy from my LBS
to look at them and see if any other parts need replacing.

Many thanks to you guys for the help and advise, gonna hit the trails on Sunday

 

[Patrick L]

I just did my first bleed last-night and oh boy what a headache. I have searched and read all i can find about bleeding them and even watched a few videos and i feel like i have a good understanding of how it all is supposed to go but for the love of me i cant get any power back in my breaks. i have used both the little bottle in the bleed kit and a syringe and i think i have gone through 2 bottles of STP trying to get this to work, i have pushed the new fluid up from the caliper and even tried doing it backwards from the leaver down and nothing. what the hell am i doing wrong?

edit: nevermind. after playing with the 2mm leaver reach screw thing, and putting brand new pads on i got it where i like it.