brake lever feel

[butthead]

i did a brake fluid flush today , i had noticed the lever was a bit too spongy in feel and although the brakes seem to work fine i put the spongy feel down to old fluid but  after changing the fluid and been careful to watch for any air , couldnt say there was any improvement in how the lever felt, i was hoping it was less spongy and less movement in it. strangely though i noticed that my 09 fz6 s2 is pretty similar in feel to my fzs, i also have a triumph Bonneville  and that lever is much harder feel and short movement before you cant move the lever anymore.


so im wondering if both my fz6 and fzs600 have a fairly similar feel to the brake lever , if that is a ' fazer thing' ?


obviously we cant ride atm , but would you say your fazer brake lever has more movement and squashy feel to it , or is it short movement and solid after ?


could be air , though i couldnt see that in the pipe ?

[FILZ6]

Pump the lever a few times to build up the pressure, then tie it back to the throttle grip and leave it overnight. See what it’s like after that. Might not work, but worth a try.

[darrsi]

When you say spongy, does it feel jerky or crunchy at all when you pull the lever?

[butthead]

no not jerky or crunchy jus ta lever that doesnt get firmer the more you pull , its the same resistance fairly much and you can almost get the lever back to the bar.  its all fresh fluid in there now   

[butthead]

Pump the lever a few times to build up the pressure, then tie it back to the throttle grip and leave it overnight. See what it’s like after that. Might not work, but worth a try.

yep i have done that .

[Gnasher]

Providing the system is all serviceable.  You've got air in the system, plain and simple.  I see a lot of this sort of thing owners utterly frustrated after DIY of their brake system.  The standard set up doesn't help either, a lot of right angles.  These help to create and trap micro bubbles, tying back the lever will help but only to a point.

[butthead]

Providing the system is all serviceable.  You've got air in the system, plain and simple.  I see a lot of this sort of thing owners utterly frustrated after DIY of their brake system.  The standard set up doesn't help either, a lot of right angles.  These help to create and trap micro bubbles, tying back the lever will help but only to a point.

im guessing you mean in the T piece ?  im sure you are right , air somewhere !

[Gnasher]

im guessing you mean in the T piece ?  im sure you are right , air somewhere !

Yep  Brake fluid is strange stuff, bit like us and carbon dioxide our bodies love it but it kills us    Brake fluid loves water (hydroscopic) and loves tiny air bubbles, some you can't even see with the naked eye   When many bleed brakes they do so not only wrongly and too fast, but with fluid that's been shaken.  Some of the stories owners tell via forums is utterly laughable, like pushing fluid in from the bottom, this just crates an almost cavitation effect and produces 1000's of tiny bubbles    Brakes are also like hearing and eyesight they fade over time and you get used to it.  It's not until they jump on something else or their brakes are bled properly that they realise just how bad they were.  Spongy brakes will pass an MOT brake test, what you lack is the bite and feel, as you've said your Bonnie, is firm.

It's like everything it's all easy when you know how.

[Disorderlypunk]

do you still have the original brake lines?? the 20 year old rubber!!!
rubber degrades over time, there is various views on this and some say replace after 6 years (preferences may differ)
i replaced mine with a set of braided from wezmoto and felt a huge difference (and looked great)

[butthead]

bikes on the OEM  rubber hoses 2001!
the braking performance  (when i last rode it ) wasnt bad, just that the lever doesnt feel like - small free movement then very firm , its  a small free movement then a squeezable rest of brake only just full stop short of the bar.  i changed the fluid yesterday but not improved the feel of the lever,  the fluid was brand new unopened and not shaken deliberatley by me ,  im guessing its best to open the container  an let it settle an hour before use though going back to gnashers point  ?  certainly didnt shake it intentionally.

[Disorderlypunk]

dont open it- just let it settle - brake fluid is hygroscopic (i think right word) so it takes in water from the air humidity
you keep saying not intentionally (dont let your kids carry the bottle lol)
im gonna stand by the brake lines need replaced they take on UV damage and repeat putting under pressure can give spongy brakes by them expanding under the line pressure as they degrade.

[darrsi]

dont open it- just let it settle - brake fluid is hygroscopic (i think right word) so it takes in water from the air humidity
you keep saying not intentionally (dont let your kids carry the bottle lol)
im gonna stand by the brake lines need replaced they take on UV damage and repeat putting under pressure can give spongy brakes by them expanding under the line pressure as they degrade.

+1 for the braided brake lines, i think you need to give your bike a treat that you will reap the benefits from. 

[butthead]

yes they say you do get a squashy feel out of rubber lines compared to braided when i looked that up today and i think thats likely the reason for how it feels .
as the brakes before the fluid change were good but the lever was squashy as it still is post fluid change stayed the same , i cant for obvious reasons ride it to double check actual braking performance yet.

[Dave48]

I know Yamaha always state change brake hoses & all rubber seals both in the master cylinder and on the brake Pistons at 4 yearly intervals. This might be a bit OTT but after 20 years there will be deterioration in all these components. From past experience of the blue spot brakes both on the 600 & 1000 FZS Fazers I always found the brakes to be light,sensitive and powerful in action with plenty of rider "feedback" through the lever.
If it was my bike I would be looking to do a complete brake overhaul and then you will have confidence & peace of mind. I use to buy the overhaul kits from Powerhouse Automotive and the braided lines can be had on a forum users discount if memory serves me right?

[fazersharp]

Yep its HEL lines tell them you are a member here for your discount. 

[butthead]

i take it if you decide to change to braided brake lines , that you still have to use the T piece splitter ? the master cylinder banjo can only fit one banjo not two?
unless there is a conversion kit , so you can go directly to the calipers with each line ?
 

[fazersharp]

i take it if you decide to change to braided brake lines , that you still have to use the T piece splitter ? the master cylinder banjo can only fit one banjo not two?
unless there is a conversion kit , so you can go directly to the calipers with each line ?
 

Its called a double banjo bolt so you have 2 lines from the master and do away with the cross piece. Look on Hel site and you will see options for a OEM 3 line kit (keeping the cross bar) and a Race line 2 line kit that comes with a double banjo. the 2 line kit is cheaper, I fitted the 2 line kit. I think if I remember right you send them an email saying you are on this forum they will send you a code to apply
Here ( not my picture )

[butthead]

ah thats brilliant! makes sense less right angles less places for air to get trapped , thanks for that 

[NJD]

New braided brake lines will provide a better feel once their fitted and bled properly, but the key in getting a good feel on the lever -- and maintaining that -- is a combination of patience and technique.


Here's how I'd tackle what you'll be doing, and I write this because you're going to need to try a few things to start you off before you can bleed the "conventional" way "ie: attaching a hose with a one way valve, or not, and bleeding the air out a bit at a time until the bubbles are gone and clear fluid flows through."


Before you do anything relating to fitting new lines start by removing the pads and pushing all four pistons in each caliper back into the caliper as far as they'll go. You'll need to remove the M/C cover and soak fluid up with a rag or use a small syringe otherwise it will overflow (pushing the pistons back in pushes the fluid back up the lines and into the M/C). Then you can put the pads and all the little bits back in and attach it to the bike.


From hereon do not press the front brake lever, yet.


Remove the standard lines and install new ones as required. The 3-way set-up may be less desirable, but takes the guessing out of cable routing; but by the same taken two direct lines are easy to "prime."


In either case, and with all the banjo's torque'd up and lines fitted, start by using a small syringe to remove most (but not all) of the old brake fluid from the M/C (make sure you leave some in at the bottom so no air gets into the system (well, more than already is). Then use a small syringe to absorb the new brake fluid from your container. Attach the syringe to a small tube of plastic hose that fits over the bleed nipple. Crack the nipple open and inject fluid through the hose into caliper, and then close the bleed nipple. Do this about four or five times.


Once that's done press the lever continuously, but only push the lever back a small amount. Pushing it all the way to the bar may damage the M/C (general advice). You should get fluid coming up into the M/C and the lever firming up slightly. You'll know you're ready for "conventional" bleeding when all four pistons in each caliper has pushed the pads against each disc. This is a time and patience part, but reverse bleeding will prime the whole system and push air up to the M/C where gravity thinks it belongs.


Once you've reverse bled you can go ahead and bleed as normal. Once you've done both calipers cable tie the lever to the bar for twenty-four hours, or overnight, and that will push the air up into the M/C and keep your lever solid.


As a tip you can also prime the race 2 line set-up by leaving one attached to the caliper and removing the other and hanging it over a jar (ie: its fitted to the M/C and bike and installed as it should be, but keep one on one caliper and remove one from the other). Fill the M/C with fluid and gently press the brake lever continuously until you see brake fluid dripping from the hole in the banjo on the brake line, and once that's done you can re-attach it to the caliper and do the other one.


~


On the whole I'd start with the syringe method, and reverse bleed to get you started. The system will be full of air, and on monoblock calipers there's plenty of space for it to hide. It will save you so much time.


If try and conventially bleed and get a rush of fluid down the caliper, or a short amount of fluid followed by nothing that then ends up back in the caliper, you know you've got a shit load of air in the system. At that point I'd cable tie the lever overnight and then start from the top of my post.


In either case you're going to be filling the entire system with air by replacing the lines. So just make sure you know how time consuming and how much patience is required to bleed a dry monoblock blue-spot system. Its not overly difficult, but as I've said a couple of times by now technique is key.


Make sure you've got plenty of kitchen roll, and those small 5 ml syringes can be gotten from Boots pharmacy (or just about any pharmacy). The same size tube that fits over you bleed nipple will fit onto the end. I wouldn't advise cable tie-ing the hose to the syringe because you're going to need to refill it, so make sure you hold the clear hose full of fluid at the same time (or buy a handful and fill them all and just use them one after the other). It's the force of continuously pushing fluid into the lines that will force the fluid before it into the caliper and push it up the lines.

edit like so:

[butthead]

thanks so much for that very useful helpful description to prime new brake lines and caliper, infact im awaiting the return of my rear caliper that ive sent off for rebuild , once its back , ill try the syringe method for priming the dry caliper before traditional bleeding ,of course ill ensure the pistons are set right back first.