[dzm3]

I have a strange problem that I can't wrap my mind around. After having had Vs on my bike for years, I decided to go with disks for the new bike build, and being a good old weight weenie I ended up getting Hope Mono Minis.
The install was a breeze, and after 1-2 miles of riding they broke in and the breaking is fantastic. But... I'm having strangest leaking problem. One of them (the front brake) is weeping fluid. As far as I can tell it's leaking from under the master cap.
The strange thing is that it's leaking even when the bike is just sitting in a car. It's a truck and I have a bike rack made int he back, so the bike is upright, not on the side or upside-down, so that's not the problem.
For the life of me I don't understandd why the fluid would leak out _UP_ when the brakes are not used and there is no pressure in the system.
When they arrived that level body was wet with fluid and upon later inspection it was low on the fluid, so I thought that maybe the air in the system was expending, we had few hot days here, and creating enough pressure to force the fluid out. But the other day I re-bled them brakes and re-filled with the fluid to the top, so there is no air in there at all, but they still keep leaking.
I called Hope customer Service, and they gladly sent me a new diaphragm (it's in the mail), so I will see if the original one was defective and wasn't creating a good seal.
But even if that's the case, why would the fluid leak up?

Especially puzzling, because the other one, the rear, is flawless and has not a hint of this problem.

If anyone experinced similar problem, or has any ideas, or explanation, I'm all ears.

Thanks
Dmitri

 

[fokof]

Too much oil on the line ?

Have you shorten the brake line when you installed them ?
Have you re-bleeded it?

 

[SteveUK]

The DOT fluid will also expand when it's heated ( that's why the resevoir is there). If the resevoir seal is defective then stuff'll come out. Fluid under pressure cares not about up n' down.
It is possible that you've over filled the resevoir, which would exacerbate the problem. The fluid shouldn't quite reach the top level when you fill it.
Peace,
Steve

 

[dzm3]

Yes the reservoir is filled to the top. I understand that under pressure the fluid doesn't care up or down. The Hope instructions say to fill it to the top, not laving any air in the reservoir.
If this was the problem then I should see both, front and rear leak the same way from sitting in the hot car, but the rear is bone dry, not a spec of the fluidon the outside, while the ffront is leaking like crazy.
I also suspect the defective seal. Waiting for a replacement from Hope. There is hope that it will fix the problem.
Just thought you guys might have some other ideas/suggestions.

Thanks everyone for help.

 

[SteveUK]

The instructions I have from Hope say to fill the fluid to "just below" the top, which is, I think, entirely ambiguous and open to interpretation. I had accepted your idea that the seal was gone, my suggestion was that this problem could be made worse by the system having too much fluid in it.
Peace,
Steve.