Harbor Freight Pump

I bought a new Harbor Freight Pump. My old one had a problem with the handles not staying on the plunger tube. However this pump will not hold a vacuum. A finger can be held tightly over the end of the pump and the vacuum drops immediately. I resealed all of the fittings around the gauge and coupling to no avail. Forget it with a tube. Anyone else experienced this or have any suggestions short of returning, which I can’t because it’s a month old and no box, no sales receipt. Thanks

Couldn’t edit post, so after blowing through the cylinder back to the pump, air can be heard coming from the back side of the pump—obviously a leak on the pump cylinder but can’t figure how to break the pump apart to check the plunger’s O-rings.

If the pump is new then send it back to the manufacturer for repair or replacement. .

But do not try and open the pump - you will ruin it.

If there is no help from the manufacturer. then as a last resort you culd try putting some olive oil - or other vegetable oil into the hole in the pump body, and working the pump to distribute the oil around the plunger.

But try and get it repaired/ exchanged first.