[herk74]

I have an 03 and have my bike down for replacing the Water pump and decided to change out the fluid in the front and rear brakes systems. I had the rear caliper off to change out the disk due to being worn. Got everything back togeather and open bleader then whent ahead and pumped the resivoir dry with the pedal then filled up the resivoir and began to bleed the brakes the brakes bled fine but after it sets and you push on the pedal it goes to the bottom have went thru several times but have not gotten any more air out of the system. any ideas or should I rebuild the Master Cyl

Ron

 

[TravelinLite]

Sounds like you have introduced air into the system. You may have to remove the rear Master to correct. PM Rocky. I am pretty sure he has procedure for doing this.

 

[James I. Jones]

You should use a Mity Vac. Then bleed the entire brake system for the rear brake. That includes both front brake calipers and the antidive.

 

[Pigeon Roost]

OP said; "Got everything back togeather and open bleader then whent ahead and pumped the resivoir dry with the pedal then filled up the resivoir and began to bleed the brakes the brakes bled fine but after it sets and you push on the pedal it goes to the bottom have went thru several times but have not gotten any more air out of the system."

Pumping the reservoir dry is your Huckelberry. Honda even describes draining the system before refilling, but I believe you can avoid much aggravation by simply suctioning out almost all of teh brake fluid from the reservoir and then purging the old fluid with new. That way, the prime is not lost. Once the prime is lost, you "should" be able to reprime. I have had success by operating the brake peddle very slowly downward while the first bleeder in the sequence is open and then slowly upward while that bleeder is closed. It may take hundreds of cycles to get a full prime. You will have to follow the sequence in the manual to get all the air out.

prs

 

[LarryM]

Letting the reservoir run dry isn't the big problem everyone makes it out to be. I have done it many times. But if you don't have the proper brake tools, then yes, you have a problem.

The master cylinder can't pump air, so trying to burp air out of it with the brake lever is a waste of time. You will get cramps in your hand before you get lucky and it starts to pump.

You need a fluid fill system, like the Mity Vac, that can suck the fluid and the air through the master cylinder. They are cheap, only about $25 for the plastic version.

You don't have to remove anything or take anything apart.

 

[herk74]

Cornfused

It is pumping up and will get tight like it used to be but if you let it set for a few min then it will push down all the way like you are bleeding it
what gives

 

[LarryM]

It is pumping up and will get tight like it used to be but if you let it set for a few min then it will push down all the way like you are bleeding it
what gives

It's just air in the system. You are looking for something complicated, but it's not.

When you stop pumping the brake lever, it takes time for the air in the system to slowly decompress. If you have your tire off the ground, you will probably also notice that the brakes drag a little right after pumping the lever. It will take a couple of minutes for it to loosen up. Once it does, you have to pump the lever again to build up the pressure.

 

[Rocky]

Like Larry pointed out.Air is in the system and sucking it out via a mity vac or like wise brake suction device is needed to remove the air.

Pumping/bleeding just the pedal will only result in wasted fluid and time as the air moves back and forth in the lines.The air/fluid needs to be sucked out together.
This happens when the reservoir is kept full and it's fluid draws the fluid & air out the bleeder valve of each bleeder in the picture below.

The rear master controls more of the Pistons/ADV/secondary master on the 1800 brake system than the front lever does.


Front Lever

Rear Pedal

 

[herk74]

MityVac

Ive Got A Mighty Vac N Ill Give It A Try

Thanks

 

[Milbear]

seems there are all type / models of the Mity Vac .. which is the one to get?

 

[LarryM]

For home use, the plastic one is all you will ever need. Mine lasted over 20 years, and is just now starting to take a dump.

Mityvac

My advice is to ignore the assembly instructions that say to hook up the bottle to the pump with the little 1 inch hose. Get a 2 foot piece of hose from the hardware store and use that instead. It makes it a lot easier when the bottle is not bouncing around while you are pumping.