Bleeding Brakes

I’ve got a 2001 Honda CBR 600 F4i and seeing as I dont know much about its history I thought I would do some simple - often overlooked - maintenance on it.

I’ve decided to try and bleed the front and rear brakes but was just wanting some pointers. This is how I intend to do it - let me know if you think its wrong!

1.) Remove brake resevoir cap

2.) Attach piping to bleeder nipple on calipers

3.) Turn bleeder screw to allow fluid release whilst AT THE SAME TIME! pouring new fluid in resevoir.

4.) Once running clear, screww bleeder nipple back up tight and replace resevoir lid.

THREE QUESTIONS THOUGH:

a.) I dont know if I should touch the brake lever - does it help in pumping old brake fluid out? How do I use this method?

b.) I presume its the same for the rear?

c.) Having 2 brake calipers at the front - served by one resevoir, I presume I have to get this just right to avoid filling one line (say to the right side) and having bubbles go up the next line (on the left side)

Your helpful hints, tips and links would be very much appreciated.

PS - I dont want to buy a fancy kit, but I am willing to stretch to some clear plastic piping - Yeah I’m cheap!

Take the lid off the reservoir.

pull the brake lever in.

Undo the nipple until the brake lever is fully depressed.

Do the nipple back up WITHOUT loosing grip on the brake lever.

Once the nipple is done up then release the brake.

Do this until the fluid runs clear.

EDIT: Only pour new fluid into the reservoir when you are on the minimum line of the reservoir. It tends to spurt out of the reservoir if you pull the brake lever too quickly.

EDIT2 : If you have one reservoir but two calipers, you do one side first, and then the other side. The bubbles won’t swap lines…

I love it when you get all technical Mole, doz things for me :P:)

:P:D

You won’t bleed the air out unless you pump the lever.

You should…

  1. Clean and Remove the reservoir cap and inner rubber.

  2. Remove the caliper nipple rubber cap and push on the clear tubing.

  3. Get a jam jar with an inch of brake fluid in the bottom.

  4. Put the end of the tube in the jar so the end is imersed in the fluid.

  5. This is the tricky bit, you need to pump the lever a few times and then, with pressure on the lever, open the bleed nipple and when the lever has hit the handlebar, do the nipple up again.

  6. Repeat until all the air bubbles have stopped coming out and the fluid is clear coning down the tube.

Tips… Cover the front mudguard, tank and any nearby paintwork with clean rags as brake fluid is like paint stripper.

Never use old brake fluid out of the garage. bin any unused fluid as once opened it doesnt keep.

I prefer to put a small 7mm ring spanner on the bleed nipple before I put the tube on.

Loosen the bleed nipple a tiny bit and re-tighten before you start the job just to check its not seized.

The night before you intend to bleed your brakes, put a cable tie on the brake lever as this forces all the air down to the calipers.

Enjoy:cool:

Some good tips there chaps - will definately apply all of this when I do it - hopefully this weekend!

PS - what mm tubing should I use? (I think B&Q sell it by thew metre!)

Any recommendations as to the Brand/type of brake fluid and where to get it?

5/6mm ID tubing. Best get it from a car spares shop.

Any DOT4 Brake fluid will do it:)

AVOID DOT5 though:w00t:

Your manual should say what DOT rating - it’s usually DOT4, but it should say so on the reservoir cap or the manual. The size tubing, if you’re talking about to fit on the nipple, should be the width of the nipple (ie, just measure it). You only need a bit to get it from the nipple to the floor.

I personally don’t use it cos I can’t see when it’s stopped running properly, I just surround the area with tissue.

Brilliant! - I’ll let you know how it goes - watch this space!

If I dont reply withing the next couple of weeks then you know I did it wrong, the brakes failed…and its all your fault!!! :stuck_out_tongue:

Are we still talking brakes here?:w00t:

Thats a dangerous way to do it if you value your paintwork:cool:

Yeah, I’m aware of the paintwork issues :slight_smile: But I take my side panel off when doing the rears, and I just use damp tissue on the front reservoir…touch wood, but I’ve never ever had a problem… once you figure out how to do it smoothly enough, you shouldn’t spill any fluid from the reservoirs, and there is no paintwork near the actual bleed point :slight_smile: it’s only the way I do it, I’m not suggesting thats the way anyone else should…I know I’m a lazy moo :wink:

I’m halfway there!

Just bought the Dot4 brake fluid and got myself a “One man” bleeding kit which means I dont have to immerse other end of the bleeding hose in fluid - also means I dont have to keep the brake lever depressed so as not to allow fluid (or air!) back up!!

Got some Part synth oil too as the oil level was looking a bit low so it needs a top up - hopefully that should get rid of the slight knock I hear every now and again!

Drumroll please!!

I’VE DONE IT!

It took me two hours instead of the usual 45mins it should take and ironically - would you believe it - the front two were easy peasy and straightforward…but the rear was a right C**T! Managed to spill some brake fluid on the rear wheel rim and also on the caliper but managed to jet wash it 30mins later…paint still on so I think I’ve got away with it.

To be honest the fluid that was in there looked fine and there wasnt any bubbles to be seen anywhere but after taking her out I realised there was less travel in the lever and a harder bite to the brakes so i guess it needed doing - massive difference in my braking confidence now.

PS - In case you’re wondering what im doing at 1:25am!
Currently in the process of taking off all the fairing and cleaning/polishing inside and out - however - after the mess I made in the bath with just the front mudguard I reckon i’ll probably keep the rest of the fairing on and just polish it up.

Gonna get some shut eye now and satisfy my OCD cleaning/polishing tomorrow first thing!

Ciao!

After you finished bleeding or just if your front brake lever seems to have to much travel, try tie wrapping the brake lever to the handle bars overnight. This always seems to make a difference!

Bumblebee,

Looks like the fairly sound advice you got worked o.k. for you, but sometimes life can be a bitch. I used to have to take the calipers off my B.M to make sure the nipple was at the top and no air was being trapped inside the callipers.

Then I discovered a pressure bleeding kit (Gunsons, I think.) It consists of a reservoir (for new brake fluid), a tube to a temporary replacement master cylinder cap and an air line that goes to your tyre that pressurises the fluid in the kit reservoir.

Total replacement of the brake fluid in ten minutes and the s**t that comes out of the lines, etc.,is unbelievable. Rock solid braking after.

It’s a bit off a faff to get sorted the first time you use it, but there ain’t no substitute.

Oldguy.