(Alachua, Florida)
Makita 700
4 years old
Will run continuously but only build 40 psi.

Used in Florida garage shop, light use with a pin nailer.
Just got a framing nailer to build a 20 foot fence and it just wouldn’t work a few days into the project.
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Makita mac700 won’t build pressure
by: Bill
Howdy Bill… that’s a pain, isn’t it, when you go to use your compressor and it won’t work properly.
Any air huffing back out of the intake port when the compressor is running?
If so, that suggests the intake valve is compromised. There are a number of valve plates for this compressor, so you might as well change them all if you are changing one. Replacing the valve plate should help stop air from backing back out and improve pressure build. Make sure if you do you replace the gaskets too.
Any air coming out of the oil fill tube when the compressor is running? That’s pointing to piston seals if there is, and you’ll need to tear down the pump to check the condition of the piston, the seals, and the cylinder wall.
Give us some idea if any of this helps, K?
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Thanks
I will definitely check both of those.
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I found this same compressor that a neighbor was throwing out. It won’t build pressure either. Mine has air coming out of the oil fill tube which points to your suspicion of bad compression rings. I’ve tore down part of the pump partially to where I can see the cylinder wall.There is no scoring. The connecting rod does have play. Not Up, Down, Right, Left. But it does have play along the crankshaft (about 1/4″ each way) if I pull/push it. Not sure if that is normal for these Makitas. From what I saw from the parts breakdown I got… Read more »