TMaas--Good luck on the 3000 series pump today! I liked your comment about the noise! I've lost a lot of my hearing due to the P pumps(lots of Macks), the Cummins PT stand and the Model 100's. It's not a good thing, but it could make it kind of peaceful if your wife starts yelling... . although, I must say, the second time around is much better, and this one has been good to me. I am just sorry that I can't hear this one clearly when she speaks when I'm in another room. Be sure to wear your hearing protection. We didn't have that when I started working these things!
"gtobey, you've cleared up a few area's but im now confused about how the rack corelates (spelling?) with the plungers and cam, barrell, but i guess i just need to see a pump or some pictures maybe a diagram, but if those arent available i'll just have to take it for what its worth untill i see one. "
BManis- The rack in a P7100 Pump is a 90 degree bar of steel about 1/2" on each side and about as long as the pump housing with 6 slots cut in one of the bent sides (one for each cylinder) to connect to the segments that the plungers ride up and down in. The rack moves within the pump housing in guides. When the rack is moved toward the front of the pump, more fuel is delivered to the injectors. When the rack is pulled back toward the governor, less fuel or no fuel is delivered. The rack is in basic terms, the direct accelerator within the pump. Keep in mind, the rack is controlled by the governor, and the accelerator pedal in the truck tells the governor what you want, and the governor then controls the rack within the pump within the calibration settings.
The segments are like steel cylinders that fit around the barrel which becomes it's guide for rotating when the rack turns it. The segment has a small arm with a ball on it that fits into the slot in the rack so that the rack can turn it, and at the bottom of the segment is a flattened area on both sides that the plunger indexes into so that the segment can turn the plunger and yet allow it to have up and down motion. The plunger bottom rides on top of a roller tappet much like a roller valve tappet in an engine, and to keep all of this following the camshaft there is a spring around it all to keep the tappet in contact with the camshaft at all times. This lower part of the pump, below the fuel gallery, is lubricated with engine oil fed from the engine. The camshaft, tappet, rack, and segment area is sealed off from the upper fuel gallery area via o-rings so that you do not contaminate your engine oil with fuel and vice-versa. Image a camshaft and roller lifters in an engine, but instead of pushrods there are plungers on top of the lifters, and they are going up and down inside of the barrels so that they can deliver fuel to the cylinders. If you want an exploded diagram which may help you visualize what you are reading, pm or e-mail me and I can send one to you.
Take care...
Attention: TDR Forum Junkies 
Course they don't compare to all the pulling pumps, they're pretty overboard. 
haha and to think i started lookin for lifter forum and kind got side tracked. dam that always happens.
