I have printed pounds of PLA also.
It depends where yours is breaking.
Mine was breaking at a built in connector. This was put in to make it easy to change out the heater.
I fixed the connector the first time the second time I just took it out and soldered the wire together.
The thing that helped the most was the black tie in this picture it sends the stress across more of the wire.
I use Trombotine Trombone Slide Lubricant
http://www.amazon.com/Trombotine-338.../dp/B0006VWYB6
For the rails someone recommended this stuff it seems to work well.
The more printing you do the more you need to keep it lubed up.