In my experience, most pumps lose their effectiveness on the upstroke.There is an o-ring in the pump cap that keeps air from escaping on the upstroke. This o-ring takes a beating from sand and any other debris that sticks to the pump shaft. In order to replace the o-ring you need to remove the handle which is screwed and glued to the pump shaft. you can use a pipe wrench or an oil filter wrench. I used an oil filter wrench as you will see in the pics below. You can use a pipe wrench by grabbing the small collar that is on the "piston head" where it connects to the shaft.
You can see where the o-ring is placed in the cap in the picture below. it can easily be removed and replaced. Note the damage on the inside of the pump cap. It is no wonder why the o-ring is damaged and not performing well on the upstroke.
- gasket in cap.jpg (85.62 KiB) Viewed 21370 times
- pulling gasket in cap out.jpg (86.99 KiB) Viewed 21350 times
This is what you will need to fix your pump
New o-ring part # 727-2215 at Napa 80 cents each
White Lithium Grease $4.00
Oil filter wrench or pipe wrench
- oil filter wrench.jpg (101.69 KiB) Viewed 21370 times
- oil filter wrench 1.jpg (91.26 KiB) Viewed 21370 times
Look at how much sand I found in one of the pumps. Before reassembling the pump, clean it out and spray some white lithium grease in the pump casing and on the pump shaft. Even it your pump is working decently now, it is still important to open it up to clean and re-grease it so it will last longer.
- Sand from pump.jpg (136.56 KiB) Viewed 21370 times
I definitely felt improvement in the pump performance after I installed a new o-ring and reassembled the pump.
Good luck with your repairs.
