Juicy breather holes

[Nuffy]

I've got a set of Juicy 5s. I've noticed, usually after turning the bike upside down, that some fluid escapes from the little breather hole on the reservoir cap. I asked someone at a bike shop about it, and he said that you shouldn't squeeze the brakes when the bike is upside down or suspended by the front wheel, as the air bubble in the reservoir is at the top and gets pushed into the system, and fluid gets pushed out the hole. I understand what he's talking about, but does this mean that I shouldn't use my brakes when I wheelie? It's also rather inconvenient to not be able to use the brakes when pushing the bike around with the front wheel up. Does a little fluid leakage like this necessetate a bleed of the system?

 

[AndreZA]

...but does this mean that I shouldn't use my brakes when I wheelie?

 

no, you should not use your brakes when you wheelie upside down.

 

 

[Hog_]

 

...but does this mean that I shouldn't use my brakes when I wheelie?

 

no' date=' you should not use your brakes when you wheelie upside down.

 

 

[/quote']

 

Normally by then it's too late anyways!

 

 

 

[Dirtbreath]

Should there be an air bubble there in the first place?

[Nuffy]

Okay, perhaps my wording wasn't so good.  Even if the bike isn't upside down, if the front wheel is raised high enough the reservoir becomes inverted, so that if there is a small air bubble it gets pushed into the system when the lever is pulled.

 

As I understand it, it's fine for there to be a little air in the reservoir in normal hydraulic systems. It allows for fluid expansion from heat, etc., and the design means that this air usually wouldn't enter the active system. However, the flip-flop design of the juicy levers means that the breather hole isn't at the highest point, and when the front wheel is raised the hole is at the lowest point and fluid gets pushed out.

 

What I'm trying to work out is if this is a design fault and the brakes shouldn't be used upside down, or if the fluid leakage is normal and I have nothing to worry about. And I'm trying to find out if a little leakage requires a bleed of the system.

 

Or something like that. Just give me answers!