Bleeding Hydralic brakes

[astrocan]

I suspect that the performance of the Hayes 9 brakes on my sons bikes will improve if I bleed them. I found a video clip which shows that I need to fit a tube over the nipple on the caliper and pump the fluid back through another tube fitted to the cylinder.
I have DOT4 fluid (fresh) and I have a clean syringe and I can get tubing, all I really need is the fitting that goes into the cylinder to attach to the tube but at least £14 for that seems a bit steep.
Has anyone successfully used anything else or failing that what size is the external diameter on the fitting?

 

[spandex]

Do they not have a reservoir with a plate with two screws? if so just keep it topped up

 

[spandex]

Before you do that have a look at the adjustment screw on the leaver. It turns out that Hayes 9s have a problem where the adjustment screw that dictates how much reach your brake levers have, can slowly undo itself causing the brake levers to move closer and closer to the handlebars. Just tighten them up and the braking should back to normal.

 

[astrocan]

The cover plate on the reservoir has two screws but it also has a plain hole sealed with a blanking plug. I believe the idea is that the system should be bled from the caliper end and I assume that topping up would be by a similar method. I have also read some reports of people treating the reservoir like one on a motorcycle, taking off the cover plate and getting into some sort of (unspecified) trouble that they would rather not repeat.
Thanks for the advice on the adjusting screw, I will deffo try that out first.