Some people shouldn't be allowed nice things...

[Luckylegs]

The obvious will probably get noticed (this place is full of detectives) but until then I'm not going to say it...

...Bike had a small lie down after falling off side stand. I may or may not have (cos I don't recall but I figure I did) depressed front brake lever in the process of picking it up. I now have one rotor noticeably warmer than the other side and a less than solid brake lever. There is no indication of anything in the brake system, forks or axle having taken any of the impact.

I'm going to be captain obvious and say that I presume this means at a very basic level there's air in the system and that furthermore given one rotor is getting warmer (but not considerably hot) than the other that the air is sitting somewhere between the good (right side) calliper and the pistons in the left.

To be honest, and I'm only commuting currently so its not too bad (I'm not needing to scrub off huge speeds), its not super bad but there's obviously summit wrong. It will be due for a service in the near future and I will get the shop to look at it (cos frankly i've got lazy and don't want to get my hands dirty) however...

My Question:
I'm wondering what the chances are (were) of getting air in the lines given the amount of fluid in the reservoir. Surely this would have been enough fluid to completely cover the entry hole to the master cylinder even when on its side so no air should/would have been sucked in.

What I expect I will get along with the Answer:
Ridicule

[Akzle]

OK, start the ridicule...

you're ugly and your mum dresses you funny

[Luckylegs]

you're ugly and your mum dresses you funny

Perhaps... although I'm a big boy now so it's my wife dressing me, and.... Stating the obvious doesn't help me with my "stoppers" question dude

[Akzle]

Perhaps... although I'm a big boy now so it's my wife dressing me, and.... Stating the obvious doesn't help me with my "stoppers" question dude

you didn't ask for help. you asked for ridicule.

[Luckylegs]

you didn't ask for help. you asked for ridicule.


The obvious will probably get noticed (this place is full of detectives) but until then I'm not going to say it...

...Bike had a small lie down after falling off side stand. I may or may not have (cos I don't recall but I figure I did) depressed front brake lever in the process of picking it up. I now have one rotor noticeably warmer than the other side and a less than solid brake lever. There is no indication of anything in the brake system, forks or axle having taken any of the impact.

I'm going to be captain obvious and say that I presume this means at a very basic level there's air in the system and that furthermore given one rotor is getting warmer (but not considerably hot) than the other that the air is sitting somewhere between the good (right side) calliper and the pistons in the left.

To be honest, and I'm only commuting currently so its not too bad (I'm not needing to scrub off huge speeds), its not super bad but there's obviously summit wrong. It will be due for a service in the near future and I will get the shop to look at it (cos frankly i've got lazy and don't want to get my hands dirty) however...

My Question:
I'm wondering what the chances are (were) of getting air in the lines given the amount of fluid in the reservoir. Surely this would have been enough fluid to completely cover the entry hole to the master cylinder even when on its side so no air should/would have been sucked in.

What I expect I will get along with the Answer:
Ridicule

Thank you for your honesty... I've edited it to be clearerererer

[neels]

Obvious questions would be which side did it fall over on?
If it fell over on the right side, and the left side brake is no longer working, there would probably be some logic to that.

Without operating the brake lever, the master cylinder will be open to the brake line to allow fluid to return from the calipers, so if the caliper ended up higher than the master cylinder it would be possible for the fluid and air in the system to swap ends. Even when returned to upright, there could still be air in the caliper if the brake line inlet is not at the highest point on the caliper.

I'm not going to ridicule, having had bikes end up on their side when stationary also.....

[Luckylegs]

Obvious questions would be...

Which side did it fall over on? Which side brake is not working so good?

If it fell over on the left side, and the right side brake is no longer working, there would probably be some logic to that.

Without operating the brake lever, the master cylinder will be open to the brake line to allow fluid to return from the calipers, so if the right caliper ended up higher than the master cylinder it would be possible for the fluid and air in the system to swap ends. Even when returned to upright, there could still be air in the caliper if the brake line inlet is not at the highest point on the caliper.

I'm not going to ridicule, having had bikes end up on their side when stationary also.....

Fell on the left, and left rotor is the cooler (and therefore the one I presuming is not functioning). I'd initially wondered whether the disc may have got knocked and bent a smidge but I certainly cant see any evidence of this on the edges of the disc itself or the carrier (especially presuming for that to have been hit there would likely be impact on the bottom of the fork legs as well) and there's no discernible pulsing (or ability to pump up the brake to pressure) or anything when braking.

I think I had my logic on the master cylinder set at "novice" but now you've said it really does confirm there could be air in there. Ho Hum...

Cheers

[neels]

Fell on the left, and left rotor is the cooler (and therefore the one I presuming is not functioning). I'd initially wondered whether the disc may have got knocked and bent a smidge but I certainly cant see any evidence of this on the edges of the disc itself or the carrier (especially presuming for that to have been hit there would likely be impact on the bottom of the fork legs as well) and there's no discernible pulsing (or ability to pump up the brake to pressure) or anything when braking.

I think I had my logic on the master cylinder set at "novice" but now you've said it really does confirm there could be air in there. Ho Hum...

Cheers

It could depend on the arrangement of the brake lines where any air ended up, easy way to find out is get the brakes bled when it's serviced and see if there is any improvement.

[Akzle]

all this to and fro.

bleed the cunts. if it goes away, hurrah! if not, report back.

[Luckylegs]

all this to and fro.

bleed the cunts. if it goes away, hurrah! if not, report back.

Yeh, I will, but... I wanted to know (and I'm not going back to edit the first post again to make it clearer) WHERE DAFUCK DID THE AIR COME FROM. Shirley with the amount of fluid in there it's have to get almost upside down for the air sitting at the top of the reservoir would get near the open hole in the master. Maybe I'm missing some science or there's a whole "sloshy" thing which agitated ze liquid enough to let the air near the hole.

Fucked if I know...


...Think I'll just "bleed the cunts" - Thank you Northland!

[nzspokes]

If when you picked it up and the orifice had no fluid in you could have pumped air in. Bleed time. Not hard.

[FJRider]

... I'm going to be captain obvious and say that I presume this means at a very basic level there's air in the system and that furthermore given one rotor is getting warmer (but not considerably hot) than the other that the air is sitting somewhere between the good (right side) calliper and the pistons in the left.



Captain Obvious might dictate ... that if the master cylinder was the issue ... both calipers would have issues. Hydraulic lines should produce equal pressure on the piston(s) of both calipers, regardless of actual length and layout of the lines. Thus I don't believe air is the issue.

Look more toward the possible issues regarding the seating of the disc pad. Pull out and check for even wear. A bit of grit in the fluids may have caused the piston(s) to stick ... a known issue in the past.

You or someone you trust could pull the caliper off and check/clean the piston(s) and seals. How many pistons in each caliper on your bike .. ???

[skippa1]

Seriously doubt that falling off the side stand onto the left side did anything to your front brakes

[awayatc]

Am fairly certain the warm side has a bent disc.
Rotate wheel and check this....
That means it wobbles and pushes out the pads thus creating the spongy feeling.
Hitting the pads in every turn of wheel will make rotor hot...

[Luckylegs]

Thanks all - appreciate the responses but time to come clean and give away why the title of my thread is what it is.

The bike is pretty much brand spankin' new, it has a grand total of ~250km on it!

So... off to the shop we go. If some of the theories are correct (particularly if its the right rotor) then this might be a warranty job.



Cheers
R

[F5 Dave]

Suzuki started the silly trend of running the connected hose over the front guard. AMA race rules for instance insist on two separate lines. They are easier to bleed and less prone to issues.

But I've never experienced what I assume you are saying.

Actually what are you saying?

Take it for a test ride down the street. Don't touch the lever.
Does either disc get hot?
If they are dragging they will. There will always be a negligible amount of drag, but not enough to get hot.

But I read as saying that after a ride using the brakes as normal, one side stays cool. I'd kinda expect the system to be unable to operate much at all if there were that much air. How much lever travel are we talking?

Can you feel/see either disc flexing when brake lever??? Nah there'd be hell noise.