Hi I have a 2003 Yamaha Warrior and yesterday I just bled my back brakes and they where nice and firm and tight. But if you leave the pedal for 10mins then push it down it has no pressure untill you pump it 4-5 times then its fine unless you leave it. I tighened up the bleeder nipple and there doesnt seem to be and fluid leaking. Got any ideas?

 

*bump*

 

Try bleading again but this time attach a suitable size hose to the niple then the other end of hose into a small container with enough brake fluid to have the end of the hose submerged .
Pump several times with nipple open watching for any air bubles coming out into container. Important to keep hose submerged.
Check reservoir fluid level from going dry while pumping.

 

Alright thanks man I was just letting it drain though the hose into the grass.

 

Ive tried bleeding them and they still lose pressure and gain pressure. Anyone have any other ideas (iam tring to stay away from buying a brand new brake system.

 

Your brake master may need a rebuild kit.

 

Forgot to say that my brakes where fine, Just spongy so bled them and they where great but then this problem started to happen. Could it be a way I bled them? (Ive tried 6 times now but still the same problem)

 

Spongy usually means air in fluid.
While keeping hose end submersed in the brake fluid container,
open niple, pump brake pedal down but before releasing pedal close niple.
Do this a few times.
See if you see any air bubles coming out.
If it loses preasure after sitting,
you may as i said earlier , need to get a re-build kit for your brake master cylinder.
New seals and "O" rings and main spring.
They normally are not that exspensive.
You should be able to get them "after market"

 

Before getting a rebuild kit , check how thick your brake pads are.
If they are wore down that could cause excessive travel.