Forklift, the air pressure is not enough, I didn't hear the air leak, and I hired several repairmen, but they couldn't solve it. What are the problems?

Unloading valve (some use oil-water separator combination valve, both of which have the same main purpose) is broken. If they are replaced, they can actually be adjusted. If the repairman changed it, it's the problem with the air pump and it won't work. The above is the problem of insufficient air pressure. If it means that the air pressure is enough when not in use, but the air pressure drops quickly when you step on the brake and runs out soon, it may be that the pipeline is blocked. Check the pipeline, just open it, and then drain the water from the gas storage tank.