Bleeding brakes

[alan sherman]

Having not changed the brake fluid for ages i had forgotten just how shit a job it is.  The problem is the pipe on the bleed nipples.  I had a kit with a one way valve, but the valve needed too much pressure so the pipe was just popping off the nipple covering everything with fluid. 
I got the job done by cutting the valve off and just using the rubber and clear pipe.   This was better but still feels a bit hit and miss as I never got enough flow from the brake system to actually see if there were any bubbles in the fluid (maybe the pipe diameter is too big - meaning fluid and air just swap sides inside the pipe).
note that I have stainless bleed nipples that may be more slippery / smaller than the standard FZS600 ones.


So what do you do?  Apart from use lots of water to clean the fluid off the discs, brakes and wheel.....

[slappy]

http://www.ebay.co.uk/itm/300mm-Solo-One-Man-Brake-Clutch-Bleeder-Automatic-Bleed-Pipe-Tube-Tool-/200345014236




I use one of these, simple, effective and best of all cheap,
The silicone hose seems to grip the bleed nipple better than the usual plastic hose,
I actually bought the 600mm long one, about a £1 more.

[andybesy]

Hey,

Last time I used a little jubilee clip on the nipple.

There's a difference between bleeding from dry and simply flushing through the old fluid with new fluid.

If your brakes are good and you just want to change the fluid then just use the bleeding method described below and you should be fine.

If you've let air in to the system or your brakes are otherwise not good then you'll need to bleed them properly. In my experience it's not so bad a job.

I've used one way values and mighty vac systems etc but for me nothing works so well as the old fashioned manual method followed by tying up the lever and leaving it over night.

I recently bled from dry after fitting new caliper's and brake lines, and found I was able to get the brakes 'okay, just about passable' within 10 minutes of manual bleeding.

But then after tying up the lever and leaving overnight you ought to wake up to find them spot on in the morning. (You'll never really bleed all the air out from dry by pushing it down, the brakes auto bleed as used).

I won't go in to tremendous detail on the bleed process as I'm sure you know it and there's loads of videos showing the process, but they key point is to proceed slowly and carefully so as to not mix up the steps and suck air in. Remembering that, it's just a matter of first popping your spanner on the bleed nipple and then a bit of tube over that, and then repeating these steps:

1) With the value still closed apply gentle pressure to brake
2) Whilst maintaining gentle pressure on the brake, open the bleed value. As you open the value the brake will give and fluid will be expelled.
3) Whilst maintaining gentle pressure on the brake, close the bleed value. Don't over-tighten.
4) Release the brake. Fresh fluid will be pulled from the reservoir.

Repeat as above, and take care not to let the reservoir run dry or you have to start over.

Don't stress about getting them perfect - get them okay, tie back the brake lever with a strong rubber band or tape or whatever then leave it over night.

It'll be better in the morning (technically it'll be better after the first couple of pumps of the lever in the morning).

If you look at the reservoir when you pump the brake (even with the bleed value closed) you'll see it expelling bubbles via the top of the system and pulling fresh fluid in.

Hope that helps, Andy

[fazersharp]

I dare not change min after last time I couldnt stop the nipple from weeeping and kept giving it and extra twist. I dont think they will come out again without snapping

[Bretty]

If your profile location is correct, you're only down the road from me. I'm in NW6 and have a Halfords kit that works fine. Your welcome to borrow it, and or tools and do it here if you like. Although it is on street parking around here.

[Bretty]

Cheap but one of the better ones I've used:
http://www.halfords.com/workshop-tools/tools/hand-tools/europat-vizibleed-brake-and-clutch-bleeding-kit

[alan sherman]

Hmm jubilee clip is an idea. I was thinking zip tie but didn't think it'd get tight enough.

My bleed kit was from Halfords.  I think the stainless bleed nipples might be smaller than the original ones.  Although the plastic retainer piece broke immediately! I might try putting the pipe direct onto the nipple rather than the rubber connector pipe.

[midden]

http://www.ebay.co.uk/itm/300mm-Solo-One-Man-Brake-Clutch-Bleeder-Automatic-Bleed-Pipe-Tube-Tool-/200345014236




I use one of these, simple, effective and best of all cheap,
The silicone hose seems to grip the bleed nipple better than the usual plastic hose,
I actually bought the 600mm long one, about a £1 more.

One problem, they're orange, how do you see bubbles in fluid?

[Fazerider]

I gave up trying to use bits of hose on the bleed nipple after finding it gets in the way and knocks the jar over when tightening the nipple. Plus, not all the fluid come out that way… a fair bit leaks around the threads.
To drain lots out to replace the fluid I’ll take the calliper off and hold it upside down over a jar.
If just getting air bubbles out and there’s not going to be much to catch, holding a rag around the nipple is sufficient.
A useful tip is to squirt some WD40 or equivalent into the nipple once it’s tightened (poke the straw down the nipple). This displaces the remaining brake fluid which would attract moisture… I’ve never had a seized nipple since I started doing that.

[celticdog]

I gave up trying to use bits of hose on the bleed nipple after finding it gets in the way and knocks the jar over when tightening the nipple. Plus, not all the fluid come out that way… a fair bit leaks around the threads.
To drain lots out to replace the fluid I’ll take the calliper off and hold it upside down over a jar.
If just getting air bubbles out and there’s not going to be much to catch, holding a rag around the nipple is sufficient.
A useful tip is to squirt some WD40 or equivalent into the nipple once it’s tightened (poke the straw down the nipple). This displaces the remaining brake fluid which would attract moisture… I’ve never had a seized nipple since I started doing that.

You've definitely got 3 hands fella! That's a good tip with the straw & wd40 

[slappy]

http://www.ebay.co.uk/itm/300mm-Solo-One-Man-Brake-Clutch-Bleeder-Automatic-Bleed-Pipe-Tube-Tool-/200345014236




I use one of these, simple, effective and best of all cheap,
The silicone hose seems to grip the bleed nipple better than the usual plastic hose,
I actually bought the 600mm long one, about a £1 more.

One problem, they're orange, how do you see bubbles in fluid?

I don't look for bubbles, when I the brake lever feels firm I just cable tie it back to the handlebar and leave it overnight.

[Fazerider]

I gave up trying to use bits of hose on the bleed nipple after finding it gets in the way and knocks the jar over when tightening the nipple. Plus, not all the fluid come out that way… a fair bit leaks around the threads.
To drain lots out to replace the fluid I’ll take the calliper off and hold it upside down over a jar.
If just getting air bubbles out and there’s not going to be much to catch, holding a rag around the nipple is sufficient.
A useful tip is to squirt some WD40 or equivalent into the nipple once it’s tightened (poke the straw down the nipple). This displaces the remaining brake fluid which would attract moisture… I’ve never had a seized nipple since I started doing that.

You've definitely got 3 hands fella! That's a good tip with the straw & wd40 

To save on the number of hands needed you can leave the brake lever where it is and let gravity do the job.