How much oil do I need to put into my electric 2.5hp, 4 gallon air compressor?

Question

I've already added one litre...do I need to put in more or is that too much? It doesn't have a gauge or a dip stick. The compressor was a gift and didn't come with a manual, and the brand is one of those generic brands (probably out of China) called American Force (no, not from the tire company). Any ideas?

Answer 1

there should be a sight glass if there isnt a dipstick but for that small of an compressor you should be pretty close

Answer 2

maybe too late but you need non detergent oil.