Brake Question

[stephenjpauls]

All,

I feel like I'm doing something wrong, and was hoping someone could give me some insight on what I should be doing...

I took my calipers off my bike, took them apart, replaced all of the seals and the dust covers after cleaning everything up. Since then I have been working on bleeding my brakes. I have pumped the brakes over 1000 times, after that didn't work I started to bleed them figuring the issue was that there was just too much air in the system and I had to get it out before anything would work. So I have been pumping my brakes then open the bleeder valve while holding the lever in, close the bleeder valve, release the brake lever and start pumping again. As I have been doing this, I'm to a point that the fluid is coming out (dribbling out, not squirting) and there does not seem to be any more air in the system (I have a clear tube attached to the bleeder and I don't seen any bubbles in the fluid coming out). There is just enough pressure when the brake lever is all the way in to stop the wheel from spinning. So I decided to ask a question here to see if there is something I'm doing wrong.

This is the stock calipers and stock master cylinder on a GSX-R600. The brakes were working well when I took the system apart... I just wanted to make sure that everything was clean which is why I did the rebuild.

Thanks for your help,
Steve

 

[jimgl3]

did you draw the fluid up with a pump or try to pour it in the master cylinder and send it down?
if the latter you may never succeed. if you don't have a pump go buy one or take your bike to the shop. otherwise you are in for much pain

 

[JVance]

Wall mart sells a syringe type thing next to the gas can accessories for 2 stroke oil measurements. That is what I use to draw fluid through the brake lines when service my brakes. That will be a lot faster than trying to pump the fluid through with the master cylinder.

John

 

[nevada]

do NOT pump the lever repeatedly.
thats BAD.
it will aerate the fluid. and you'll NEVER get all the air out.

does that MC, have a bleeder?
if so, bleed the MC first.

run a clear tube, from the bleeder, back into the res.
pull the lever. do so, until your not getting anymore bubbles.

if the fluid is cloudy looking(those are millions of bubbles)
just walk away, and take a break.
give it 10 min or so, then try again.
once u get clean/clear brake fluid from the MC.
move onto the calipers.


for every time you pull the lever, open the bleeder.

 

[lunchmeat]

There is an air bubble hung up in the banjo fitting by the MC. Try bleeding from the MC bleed screw if it has one like nevada said. If not, pump up the lever, hold it down, and crack the banjo bolt loose like a bleeder screw. The air will come out there and then you will get pressure back after a few times. All the bleeding in the world at the calipers won't do anything until you get the air out at the MC. Good luck.

 

[stephenjpauls]

I'm going to try this today... I read in another post to zip tie the brake lever, I did that and its 25% better after letting it sit like that over night. But it still needs work. Unfortunately for me the stock master cylinder doesn't have a bleeder so I will try the banjo bolt trick. I'll post results this afternoon.

Cheers,
Steve

lunchmeat;23431 wrote: There is an air bubble hung up in the banjo fitting by the MC. Try bleeding from the MC bleed screw if it has one like nevada said. If not, pump up the lever, hold it down, and crack the banjo bolt loose like a bleeder screw. The air will come out there and then you will get pressure back after a few times. All the bleeding in the world at the calipers won't do anything until you get the air out at the MC. Good luck.

 

[bigkaley]

You had said that you had disassembled the calipers and installed new seals and dust covers (seals??). Did you install new O-rings in the caliper halves? New washers at all banjo bolts that were removed? Were caliper half bolts and banjo bolts torqued to spec (not too tight)? Does the bike have braided lines? How old is the master cylinder? When was it last rebuilt?
Then like suggested above, start at the top and work down. If you're gonna do it, do it right and do it once. Good luck and be patient.

 

[stephenjpauls]

bigkaley;23516 wrote: You had said that you had disassembled the calipers and installed new seals and dust covers (seals??). Did you install new O-rings in the caliper halves? New washers at all banjo bolts that were removed? Were caliper half bolts and banjo bolts torqued to spec (not too tight)? Does the bike have braided lines? How old is the master cylinder? When was it last rebuilt?
Then like suggested above, start at the top and work down. If you're gonna do it, do it right and do it once. Good luck and be patient.

New O-Rings (Yes)
New Washers (Yes)
Torque on Banjo Bolts (Yes)
Torque on caliper halves (No, I don't have a metric Allan socket that will work with my torque wrench) - They are not leaking
Lines - (Not sure if they are braided... they are not stock, blue with Teflon coating, both lines come from the master. Came with the bike)
Master cylinder, not sure how old or when it was last rebuilt, it was working great 3 days ago before I started this job.


I bleed the master from the banjo that comes out of it and now I have good pressure in my system... I think there is still a touch of air in it so I'm going to bleed the master 3 more times then re-bleed at the calipers.

Cheers,
Steve

 

[Thunderace]

I bought the Mighty Vac from Harbor Freight and it's been a breeze to bleed the brakes. I use it to get 99% of the bleeding done and then do it manually just to make sure. Well worth the price.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39522

 

[physicistkev]

no offense to anyone here but I just do it

fill reservoir
uncork bleeder
squeeze brake
recork bleeder
let go of brake
uncork bleeder
squeeze brake
recork bleeder
let go of brake...

check the reservoir about every 8 cycles and add fluid as needed

I just serviced 2 sets of calipers (Tokico 6 pistons) in this fashion. I have a bleed type banjo bolt on the master cylinder. I recommend this to anyone. I started with the right side caliper, unless you use a series style brake setup (master to one brake caliper then from that caliper to the other brake caliper) it doesn't matter which one you start with. Do both calipers, then do the master cylinder then do the calipers again. If it feels good then your set, if not then start at the master and then do the calipers again. Repeat until it feels right. It's usually right the first time.

Kevin

 

[nevada]

physicistkev;23729 wrote: no offense to anyone here but I just do it

fill reservoir
uncork bleeder
squeeze brake
recork bleeder
let go of brake
uncork bleeder
squeeze brake
recork bleeder
let go of brake...

check the reservoir about every 8 cycles and add fluid as needed

I just serviced 2 sets of calipers (Tokico 6 pistons) in this fashion. I have a bleed type banjo bolt on the master cylinder. I recommend this to anyone. I started with the right side caliper, unless you use a series style brake setup (master to one brake caliper then from that caliper to the other brake caliper) it doesn't matter which one you start with. Do both calipers, then do the master cylinder then do the calipers again. If it feels good then your set, if not then start at the master and then do the calipers again. Repeat until it feels right. It's usually right the first time.

Kevin

thats exactly how i do it.

on a bike, a mighty vac really isnt necessary. with a car/truck, where you cant operate the brake, WHILE reaching the calipers...thats fine. but the bike is EASILY done by yourself.

also, u have to be careful..if it doesnt seal up right, you can pull air into the system with it.