If you pump it up and then put a light pressure on the pedal does it hold pressure or slowly sink to the floor? If it sinks, then the master is bad. I've seen "brand new" rebuilt masters that were bad, so don't rule that out because it is new to you.

Jon,

That is exactly what is happening. Funny thing is that both my new and old M/C's do it.

I'll try returning my master cylinder to Napa and get a new one. Will update on progress later this weekend.

Thanks for the input everybody!

If you pump it up and then put a light pressure on the pedal does it hold pressure or slowly sink to the floor? If it sinks, then the master is bad. I've seen "brand new" rebuilt masters that were bad, so don't rule that out because it is new to you.

Jon, could that also be indicative of a leak some where in the system? Basically it is bleeding pressure through some means, either a bad master, leaks around the bleeders, etc.

Jon, could that also be indicative of a leak some where in the system? Basically it is bleeding pressure through some means, either a bad master, leaks around the bleeders, etc.

No. If it were leaking through a fitting it would leak faster when you step on the brake pedal faster. What happens is the primary seals in the master don't seal against the bore anymore when they are relaxed or there is little pedal pressure. When you stomp on the pedal the fluid pressure pushes the seal against the bore and you get a hard pedal.