When you drop a new grease cartridge into a gun - say a Miwaukee 18 volt power gun, what happens when you unhook the plunger rod from the cylinder, and push it in? Does the rubber plunger hit the end of the grease, and stop under spring pressure, while the plunger rod sinks into the grease? And as the grease gets expelled from the gun, the spring loaded rubber plunger moves the grease to the front of the gun? Or does the rubber plunger immediately move to the front of the gun, pushing the grease out of the tube? For some reason, my Milwaukee 18 volt gun plunger rod does not want to go more than an inch into the brand new grease tube, and I'm trying to figure out what's going on.
Your gun is working as it should. The rubber plunger pushing the grease is spring loaded to put residual pressure inside the tube to keep grease pushing into the pump. Look at it as a gauge on how much grease you have left in the tube. This can be very handy to know when say for example you're greasing the lift arms on a 953 and about to go on your knees to grease the inside zerks on the front idlers and the inside lift cylinders. Last thing you want to do is crawl down there and run out of grease.
The plunger will not push into the cylinder. It's hanging out about ten inches. Do I need to rotate the plunger rod to get it to push through the rubber dam?
I know sometimes you have to blead the air out of some guns before they will pump, either hand or electric. Seem to recall some had a push button valve on them. Need to do this more with a new gun or one that has been run completely empty.
Just use it, that's normal with a new tube. If the gun is pumping grease the rod will retract into the gun until the tube is empty. If the gun is not pumping grease like Kshan said there is a button on the side of the gun to release the air inside the tube. Push it in until grease comes out the end of the gun. When the rod is sucked up to the tube on the gun you'll be out of grease very soon.
Also forgot to mention that many grease guns have that rod keyed in a way that you can put pressure on the piston then turn it say 1/4 turn and it will slide down into the grease tube.
You need to rotate the rod to get it to push in. I know I read that in the fine manual, but it didn’t register. Rod goes in now.
Install one of these if you don't have already and you'll be happy you did: https://www.amazon.com/dp/B00H7LPKKU/ref=redir_mobile_desktop?_encoding=UTF8&*Version*=1&*entries*=0
I did. I can't imagine screwing and unscrewing a standard grease gun nozzle.