Bleeding brakes on kat f/e

[bucks1605]

I've been trying to bleed my brakes for quite some time now, and I just can't seem to get a firm feeling at the lever. Does anybody have any fool proof bleeding techniques? I'm really getting frustrated with this. It seems like I've purged all the air from the system, but I can easily squeeze the brake lever all the way to the grip. I'm using the gs master cylinder, if that makes any difference.

[joshr08]

i think the gs master is your problem from what i hear you need to upgrade to get a better feel with the double front calipers

[bucks1605]

I'm starting to think that's the problem too. I just went out again, and I'm about 99.5% sure there's no air in there, at least not enough to make the lever as soft as it is. So what's the common upgrade? Isn't a gsxr master?

[The Buddha]

GSXR master cyl from the 90's were not that great. I run katana master. However the standard problem is that at the master you're not pushing fluid. if it gets crap in there in just the right way, well, I ahve had 2 bikes with this problem so I'd say its not even that uncommon, I will venture to guess its got no pushing power. I have typically been able to get all fluid out, then put in acetone and push that through and use it to clean and flush the stsyem. It has to be dry and clean. Pumping with acetone is bad, but letting it sit and soak and getting the fluid out is not too bad. Use a bleeding pump and suck it out. Top or bottom, no big deal. In a way, you're better off sucking out of the top with dirty fluid if its very dirty. If its clean enough, you can push into the system and remove from the caliper bleed while filling in the top.
Anyway ... I prefer to tip the reservoir thing out, suck the rest from the bottom, flushing with acetone, and then using DOT5.
Cool.
Buddha.

[ineedanap]

if the buddah says run the kat master you probably should run the kat master 

If it helps, when you do brake lines or something major it is pretty common to get an air bubble (and crud like buddah said) stuck in the master so it won't pump correctly.   I usually use a giant syringe and some hose and force fluid up from the bleeder thru the system.  that way all the air bubbles work their way out the top.  Then I bleed it normally.

And if you run dot 5, make sure you flush it like buddah says.  Dot 3,4, and 5.1 are compatable with eachother.  Dot 5 isn't.  Mixing any of those with 5 is bad. 

[bucks1605]

I think I might have a kat master out in the garage somewhere, I'll give that a try tomorrow.

Edit: Just found the kat master and threw it on. I'll have to wait until tomorrow to bleed the system. On a side note, the lever on the kat master would stick when I squeezed it in, so I removed up a nut on the underside and now it returns freely. Is it ok to leave the nut off?

[ineedanap]

You should be able to screw the nut and the bolt as tight as you want since there is a step built into the bolt to prevent it from squeezing too tight.  You probably just need to pull the nut and bolt.  The lever will pull right off and i bet you'll find a bunch of crap between the lever and the perch.  It acts like a shim and the little extra squeeze from the nut is all it takes to make it stick.  A good cleaning and a dab of grease on the bolt should take care of it.  I used to have this problem pretty often when I raced motocross (badly) since people were always throwing dirt on me.

[bucks1605]

You should be able to screw the nut and the bolt as tight as you want since there is a step built into the bolt to prevent it from squeezing too tight.  You probably just need to pull the nut and bolt.  The lever will pull right off and i bet you'll find a bunch of crap between the lever and the perch.  It acts like a shim and the little extra squeeze from the nut is all it takes to make it stick.  A good cleaning and a dab of grease on the bolt should take care of it.  I used to have this problem pretty often when I raced motocross (badly) since people were always throwing dirt on me.

Thanks, I'll give that a try in the morning.