No front brake at all

Yung41

Registered
Has anyone had any problems with front brake master cylinder or had to replace the master cylinder on the Busa? Brakes won't bleed up and it's driving me mad, can't get a lever at all.
 
When you say you "can't get it to bleed" what exactly are you saying...?
and What brought you to this? Brake pads, new rotors, etc...? From my own experience I can say it takes for ever to bleed new lines on the front. What method are you using?

More questions:
What year Busa?
Stock/aftermarket Brakes, lines, calipers, etc.?
When did you first notice problem?



<!--EDIT|ks-waterbug
Reason for Edit: None given...|1084817387 -->
 
I understand the term Bleed, I just want to make sure were on the same page. When you started to bleed the system did you remove any of the brake components? Lines, brake piston assy, etc... ? This is important as the amount of time it will take to get it up and running very's by how tore apart the system is from factory orginal. Also, aftermarket brake lines tend to run double lines from the master down to the front calipers, OEM is a single with one cross over...
 
Problem started after winter park-up. Had to free up seized pistons & popped the dust seals at the front of the pistons in the process
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. So fitted complete new seal kit put calipers back together & refilled the system with fluid all as per manuel. Bled the brakes by pumping and holding lever while opening bleed nipples. No joy, so fitted seal kit in master cylinder thinking that may be the problem but still no lever. So now i'm f#$ked off. No mods to bike all original.
 
If you're not using a vacuum to bleed the brakes the process can take from a few minutes to several hours...... Seems every time I've done a set that just when I'm about to give up it finally takes! I bet you still have air in the system, there is a brake bleeding kit you can use (not the mighty vac) that only cost around $3. Its nothing more than a plastic bottle with a rubber hose attached to the top. I'm not sure who or where you can get them, but it'll make the job go by real fast..... Is the lever still spongy?
 
With the front wheel off the ground on stands i'm struggling to get enough pressure from lever to stop the front wheel from turning by hand
sad.gif
. Had two mechanics look at it and both gave up after suggesting it was a defective master cylinder. Now trying to get hold of a working cylinder to prove it before buying a knew one.Thanks for replying
smile.gif
.
 
Did you remove "All" the trapped air from the system?
Double check and Recheck to make sure your using DOT 4 brake fluid
Did you make sure the fit up of new parts was correct and nothing was left out. (o-ring comes to mind in the pistion assembly)
Master cylinder: Visually check and make sure there were no visual signs of wear, scratches, pits or dings? What about the piston assy. dbl check this?
Finally is the system holding fluid? No leaks anywhere? I try and keep things simple before I move on to the more expensive/time consuming fixes....
I am most concerned about the fact that over the period of time you stored your bike the pistons became seized. This is most troublesome....
You never did say what year your bike was.



<!--EDIT|ks-waterbug
Reason for Edit: "Regroup thoughts"|1084919407 -->
 
Thought of one more thing...
First the o-rings in your caliper's is generally what is used to retract your piston assembly. When these go bad or are misaligned a stuck piston (brake) often is the result and in your case over the long storage of your bike contributed to this condition. Brake fluid escaping around this o-ring can cause the piston to extend even more (this is due to the corrosive nature of brake fluid). The only other thing that comes to mind is (and this is a long shot) the brake lines up front. If the main line were to collaspe this would also contribute to your inability to bleed the system. The later is not very common, but not unheard of. How old is your bike? Last, as you suggested is the master cylinder. Generally when these go bad they tend to leak, not always but generally!
 
A brief history then. First the bike is a year 2000 model with no mods. I moved to present address only recently and so don't know any local bikers yet (dont know any locals yet!!).
Not much cash either hence doing jobs on it myself (do have engineering background but not mechanical or bike related) working from Suzuki manuel. The bikes done about 18,000 miles in all types of weather. I must have spent days over a couple of weeks trying to bleed brakes and was convinced i must have gotten all the air out, now however i'm not so sure. Was real careful fitting new seals & o-rings but If cylinder proves to be o.k I will have to split the calipers again, check the seals and start from scratch.
 
I know from experience this is a pain in the keyster! Last time I did this to a busa it took almost three hours to get it completely bleed up front! I didn't have a vacum so I had to do it by hand........ I never did figure out why it wouldn't take. The lever was spongy right up to the last minute and then "POW" it finally took. Don't give up I sure its something simple.
 
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