So I've been having the issue of pulling hard to the right when braking.  Today I bought new calipers and inspected the front brakes.  I noticed that the pads on both sides of the truck have worn evenly.  However when I removed the calipers and pumped the brakes a few times, the right caliper extended near full travel and the left one hadn't moved but a tiny bit.  I put the new caliper on the left side and got the same result.  I then swapped the old caliper back onto the left side and fluid did pour out of the caliper. 

Does this indicate a problem with the master cylinder?  Could it be an issue with a worn brake hose.  I've read they can sometimes close off.  I din't notice any deforities in it but I can't remember replacing it, so its been a long time if ever.

What should I check for next?

thanks

Jon