I have a pair of 07 juicy 5 brakes that have basically never been bled as I use them as spares and stand-ins. They have been off and on a number of bikes and have definatly had a considerable number of descents put into them.

Recently put them on my XC bike and the power just seems less than you would expect. Changed the pads and disc, still no improvement. Brake feels firm as ever, no pumping of the lever or anything.

I was wondering if the age of the hydraulic fluid in the lines may be having an effect on the power? Seems to be the only explaination left.

It shouldn’t have any effect on power. Brake fluid does degrade in two ways – it absorbs water which reduces its boiling point making failure after repeated use more likely and it becomes contaminated with particles from wear and that get past the seals which accelerates wear.

It should be changed every year

Juicys are a bit prone to sticking pistons….this would give symptoms of reduced power and the lever feel neednt feel any different.

We recommend replacing fluid at least every 2 years and Avids seem to like new seals regularly as the levers tend to become slow to return to the parked/off position.

Depends what the fluid is – do Avid use DOT fluids or Mineral Oils?

Mineral oil fluid doesn’t absorb water so that may not be the problem.