Unless it means the pistons are being pushed back by a warped rotor??
Brake fade after parked for 4 days
- Thread starter Parmenion
- Start date
Ok, so here's an interesting piece of info that relates to this situation . . .
I mentioned this issue with our top tech at the Suzuki shop I'm working at and he told me they had a front brake master cylinder recall on a particular GSXR model years ago, turned out it was a similar symptom, the same as described here, after sitting for a short period the brake lever pulled into the handlebar on the initial pull, and then pumped up to normal operation.
Suzuki Japan issued a recall and warranty replacement on the Master Cylinder . . . but here is where it gets interesting . . turned out that there was a certain component in the internal parts assembly of the m/cyl where the material it was constructed with reacted to brake fluid and caused minute air bubbles to form (due to the chemical reaction). The bubbles would accumulate over a period of time and eventually cause a "spongeyness" in the lever on the initial pull, then the air would exit through the reservoir and all pressure was restored to the lever feel on successive pulls.
This was dependent on the bike sitting still for a period of time where the fluid and the component material could react sufficiently to cause this issue.
Obviously while the engine is running and the bike moving, the vibration is nullifying this effect, with any air generated being moved to the reservoir and exiting the system, so as to not cause the brake system to fail.
It will be interesting to watch this and see if it is revealed as to exactly what the cause of this brake pressure issue is.
If I hear anymore I'll post up the info . .
Kiwi over and out!
I mentioned this issue with our top tech at the Suzuki shop I'm working at and he told me they had a front brake master cylinder recall on a particular GSXR model years ago, turned out it was a similar symptom, the same as described here, after sitting for a short period the brake lever pulled into the handlebar on the initial pull, and then pumped up to normal operation.
Suzuki Japan issued a recall and warranty replacement on the Master Cylinder . . . but here is where it gets interesting . . turned out that there was a certain component in the internal parts assembly of the m/cyl where the material it was constructed with reacted to brake fluid and caused minute air bubbles to form (due to the chemical reaction). The bubbles would accumulate over a period of time and eventually cause a "spongeyness" in the lever on the initial pull, then the air would exit through the reservoir and all pressure was restored to the lever feel on successive pulls.
This was dependent on the bike sitting still for a period of time where the fluid and the component material could react sufficiently to cause this issue.
Obviously while the engine is running and the bike moving, the vibration is nullifying this effect, with any air generated being moved to the reservoir and exiting the system, so as to not cause the brake system to fail.
It will be interesting to watch this and see if it is revealed as to exactly what the cause of this brake pressure issue is.
If I hear anymore I'll post up the info . .
Kiwi over and out!
Berlin Germany
Registered
@Kiwi Rider
and @Parmenion
my idea would be
to exclude that issue with the rubber (seal) in the gen3 brake mc
i would change the gen3 mc to a used gen2 / gen1 mc - as far as i see all 3 have the same piston diameter : 5/8"
so the pure mechanic should work
and the weird behavior of the gen3 mc should be ended, i hope.
eventually the brakeswitch of the gen2/1 mc will work also at the gen3 too.
if so, one can test this provisional "repair" while next rides
and also while next 4-6 days paused bike,
means the pressure in the system should no longer disappear and the mc should work as usual.
and @Parmenion
my idea would be
to exclude that issue with the rubber (seal) in the gen3 brake mc
i would change the gen3 mc to a used gen2 / gen1 mc - as far as i see all 3 have the same piston diameter : 5/8"
so the pure mechanic should work
and the weird behavior of the gen3 mc should be ended, i hope.
eventually the brakeswitch of the gen2/1 mc will work also at the gen3 too.
if so, one can test this provisional "repair" while next rides
and also while next 4-6 days paused bike,
means the pressure in the system should no longer disappear and the mc should work as usual.
Almost sounds like they need a recall....this is a serious safety issue...
I'd be calling Suzuki and talking to them.
Hayabusa Wannabe
Registered
QFry
Registered
Sorry for lateness of reply. Here is an article that explains it better than I could.
Pad Knock-Back - What it is, how it happens — and what to do about it - NASA Speed News Magazine
It is a car specific article but it applies to motorcycles as well.
alybry3
Registered
Just got the bike back from the dealer. I was told that there was air in the brakes which they bled out. They could not explain how the air got there as the reservoir still showed full and there are no evidence of leaks. My experience with air in the brake system (in cars) is that they are squishy all the time. The symptoms with my Busa was intermittent. Time will tell. Their first explanation was that I wasn't squeezing the lever correctly. Ummm, yeah, okay. I like my dealer and the service rep though so just let that one go!
InfiniteReality
Registered
I was not aware of this until now and have no felt anything off about the brake feel. I'm around 800 miles.
The Dealer needs to be replacing parts this time, and I'de be calling Suzuki Coperate.
That's at minimum a bad front master cylinder seal, and I would be concerned about the abs pump as well.
If Suzuki had any sense or decency they'de replace the whole brake system.
Braking and someone's life is no place to guess, especially since the problem came back.
That's at minimum a bad front master cylinder seal, and I would be concerned about the abs pump as well.
If Suzuki had any sense or decency they'de replace the whole brake system.
Braking and someone's life is no place to guess, especially since the problem came back.
^^^ yep, there is something drastically wrong with the system from the factory....
Check your state's Lemon Law.
In Va, if the dealer fails to fix it after the 2nd time, you can bring it back a 3rd, leave it, and take your tag off of it.
I'de get a good lawyer that will sue for his fees as well.
Since there are no visible fluid leaks, it's obviously pulling in air somewhere.
With linked brakes and several more feet of brake lines and the abs pump, guessing is out of the question, and from the factory this way.
Again, push for a new brake system.
I'de also get a blacklight marker and mark Every line, caliper, mc's, and abs pump.
Then check after, if they lied, the lawyer, the BBB, local news, and Suzuki would all hear about it.
It's Your life and possibly others at stake.
In Va, if the dealer fails to fix it after the 2nd time, you can bring it back a 3rd, leave it, and take your tag off of it.
I'de get a good lawyer that will sue for his fees as well.
Since there are no visible fluid leaks, it's obviously pulling in air somewhere.
With linked brakes and several more feet of brake lines and the abs pump, guessing is out of the question, and from the factory this way.
Again, push for a new brake system.
I'de also get a blacklight marker and mark Every line, caliper, mc's, and abs pump.
Then check after, if they lied, the lawyer, the BBB, local news, and Suzuki would all hear about it.
It's Your life and possibly others at stake.
Ridgeracer65
Registered
Just had this happen to me pulling out of the garage this morning. I’m at 4000 miles and haven’t had any problems till this morning. Kinda had me shook up on my ride to work this morning. Hopefully my dealer will correct the issue.
Hayabusa Wannabe
Registered
Welcome to the site @Ridgeracer65. Some awesome riding in those Blue Ridge Mountains I presume. I hope you get the brake problem cleared up quickly.
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