I find my kite pump, over time, gets really hard to push and I can't get enough pressure in the kite. I've tried lubricating it with
- vasoline
- axle grease
- WD40
- machine oil
- suntan cream
- spit
I've cleaned the sand out and put vaso on the rubber bits. It works fine for a while but after a week or 2 it slows up again. It has an aluminium shaft. And don't tell me buy an electric one - this is my warmup but I don't want shoulders like Arny.
Any suggestions? 
silicone spray. lasts way longer than anything else. give it all a good clean and then spray just a little bit on the shaft, the seals and inside the cylinder. i'm a pedant and a perfectionist and still i only do mine every 20 kites or so. takes me about two minutes.
I've tried all the lubes...they work for a while but sand sticks to them and they deteriorate the plastics. I find that the pumps work only for so long, but the key is that they are hot....meaning: if you live in a nice hot place like WA just leave the pump in the sun to heat up and you'll find the pumping lots easier.....just my experience and I've use heaps of pumps and used to pump a kite a day of 6 years.
