What are the reasons why a balloon pump cannot inflate?

[MacCooper]

When connecting the pump to the valve, the air needle is not pressed into the valve, the air outlet is blocked, or the connection between the pump and the valve is poor, causing air leakage. The reasons and solutions are as follows: Reasons: When connecting the pump to the valve, the air needle is not pressed into the valve, the air outlet is blocked, or the connection between the pump and the valve is poor, causing air leakage, which prevents compressed air from entering the valve. Solutions: When connecting the pump to the valve, make sure to perform a pressing action to ensure the air needle is pressed into the valve before inflating. When using the pump, connect its air outlet tube to the valve. The valve's function is to only allow air to be pumped from the pump.

[McJoseph]

When my kid had birthdays, we often ran into the issue of the pump not inflating properly. After some troubleshooting, I figured out a few common problems. If the black rubber head of the pump is cracked or deformed, it leaks air when pressed down—this is especially common. Also, if the intake valve gets clogged with dirt, like dust or balloon fragments, the valve flap won't seal tightly. If the connector isn't firmly attached to the balloon nozzle, air leaks out while pumping, making all the effort pointless. Plastic pumps can develop cracks in the body after long-term use, which are only visible when held up to the light. My usual approach is to try a new balloon first. If that doesn't work, I disassemble the pump to clean the valve flap. If the rubber head is worn out, I cut a piece from a bicycle inner tube to replace it—it's cheap but very effective.

[Vivienne]

Last time our company held an event, we broke five air pumps, but we learned a few things. The most annoying issue is the one-way valve failure—that small rubber disc either deforms or gets punctured, causing air to leak everywhere. Worn piston seals are also troublesome; new pumps start leaking after just a dozen uses. Now, I first check if the balloon nozzle is fully secured over the air outlet, then disassemble it to see if there’s debris inside the valve. Plastic pump bodies tend to crack at the seams, while metal rods bend easily—these are things to watch out for. For short-term fixes, wrapping the connection with plastic wrap a few times can work, but for long-term solutions, it’s best to replace the parts. Buying a repair kit for three yuan on Taobao is the easiest fix.

[OMaggie]

Actually, the air pump works by compressing air with a piston. There are only three parts that can cause it to fail to pump air: a damaged rubber cup will cause air leakage, a deformed valve disc will allow backflow, and a loosely attached balloon means wasted effort. I've taught my child to fix it by disassembling the pump into three parts: the piston rod, the barrel, and the valve assembly. If the rubber cup is worn out, replace it with a bicycle valve rubber pad. If the valve disc is stained with nail polish, clean it with an alcohol swab. If the connection is loose, reinforce it with a rubber band. Repairing is more cost-effective than buying a new one, so now we always keep spare parts at home for repairs.