Front Brake Bleeding
 

I just brought home a new (to me) 2003 CBR 954 RR. The front brake is "spongy" so I plan to purge the system, removing all the old brake fluid, then put in new DOT 4 fluid.

My question: How many bottles of Honda Brake Fluid should I have on hand before I start the job?

I want to be sure to have enough to thoroughly bleed the system.

Thanks for any advice you can offer.

Sandy

I would say two small bottles should do front and back.As far as the process goes , get a vacuum pump and it makes it much easier. No need to drain the system, it will only make more bubbles. Just add new fluid and use a clear tube from the bleeder to watch the fluid color change. Keep adding, pushing the old fluid out with the new. Don't let your reservoir go dry. If you do drain the system ya might as well put on some ss lines, ya can prolly get em for like 100 bucks. If you have problems with bubbles you can take the caliper off and hold it in the air. The bubbles will rise and make it a bit easier.

if it feels spongy, you can bleed it all day and not get rid of it. what you need to do is prime the master cylinder. you have to do this anytime you let the reservoir run out of fluid. let me know if you need directions on how to do that.

+1

I think I got mine for $15 at Autozone. Well worth it!

I have been having a hell of a time getting my brakes firm. I can still squeeze them to the bar when I pull very hard. I have SS lines. I opened up my calipers and cleaned everything. Bleed them compeltly again and it is still the same issue pulls to the bar when I squeeze hard. What is this prime the master cylinder? I have heard of bleeding a master cylinder but I dont know anything about that either, I have tried leaving them bungyied (sp?) overnight and then bleeding again with no help.

It can take up to 100 times or more of the pump/release method. The thing is, its not like a car where your moving and inch or so of fluid, your only moving 1/16 of an inch or so of fluid, so you can imagine if you have air in the system, how long it is going to take to get that air moving that far. Even then, sometimes the air is in a spot that small amount the fluid is moving, doesnt move the air any further down the line and you can never bleed them.


My suggestion is as MC_spirited said, get a vaccum pump and it will be bled in a matter of minutes. I see them on ebay all the time for around 30 shipped. I don't know the quality of them, but if I was pinching pennies, I think I would go that route. It is a wise investment. You can pump a lot of volume through your entire system and clean it while you bleed it as already mentioned.

I posted the procedure in the "how to" section. it has to be approved by a MOD and hopefully Patric will move it into here...

Check out this thread

https://cbrforum.com/forum/how-mechanical-40/how-bleeding-your-brakes-prime-master-cylinder-104677/

This is true a mastercylinder can need to be bled, Fill it with fuel and lightly pump the lever. Air bubbles will come up, when the bubbles stop you are good