Air compressor

[jjrbus]

I have a MZB 1100-24 quiet air compressor, need to sort this out but do not know what I am doing. Compressor quickly reaches 115 psi. I am trying to fill a tire that requires 80 psi. I can get about 73 psi in the tire and it will not fill anymore. Looks like the tire pressure and the tank pressure have eqalized? The compressor low cut in psi looks like 72 psi. Thinking tire pressure is stopping psi from dropping low enough to restart compressor? I can fill front tires to 65 psi with no issue.

Owners manual is no help. Am I on the right path? Any thoughts, ideas, suggestions, advice or wise cracks greatly appreciated. I can fill front tires to 65 psi with no issue.

 

[mikedodge]

Yeah that's what's happened. It's equalled out so there's no higher pressure to force air into the tire. Pull the chuck off and open up a line to get the compressor low enough to restart.

If that's a constant problem and you don't use the compressor for much else you could always bump up the low side of the switch so it kicks on at a higher pressure, but that might make it run more for no reason if you use it for a lot of other things.

 

[The Cobbler]

72 seems low for kick on, but it all depends on the rated tank pressure etc.
I agree the cut in is what's affecting your tire fill. drain some air to get the compressor to kick on and build to it's max, then fill the tire to required pressure.
If it was me I'd be exploring raising the high side of the pressure switch... but caveat emptor

 

[mm08822]

A quick search of that model number states it has a max pressure of 115psi. Cut-in at 72 seems very low as others have stated.

Unless this low cut-in pressure is something new and was higher before, it seems like the setting is too low. I'd raise it to 90-95 psi and make sure the cut out pressure doesn't exceed 115psi. Check tank for MAWP pressure also. There should also be a pressure relief valve as a backup to the pressure switch cut-out.

 

[RTM]

Do you have a regulator on your output? I have a tank pressure and regulated pressure outputs on one compressor.

 

[jjrbus]

Thanks for the input, greatly appreciated. So I go to You tube and look for low pressure adjustment and piece of cake, adjust the screw. Except I do not seem to have a screw, noting on the bottom either. There is one hex head bolt to control pressure. I tried but cannot post of video.

This low pressure is not new but have only used the compressor a few times. Regulator on output, yes.

 

[RTM]

Regulator on output, yes.

Is that regulator cranked all the way up?

 

[jjrbus]

Is that regulator cranked all the way up?

Not all the way no, cannot output anymore psi than is in the tank.

 

[david3921]

You have this style of pressure switch.

 

[jjrbus]

The hex nut controls the cut in and cut off pressure. In order to raise the cut in pressure to 80 psi I have to increase the cut off pressure over the 115 psi rating of the tank. Raising the pressure past the rating on a cheap chinese tank, what could go wrong??

 

[mikedodge]

So you're down to what I suggested before or buy a new pressure switch.

 

[gimpyrobb]

What happens at 80psi that 73 isn't good enough for? Are you certain your gauge is reading correctly?

 

[jjrbus]

I am **** about tire pressure and gauges. I have a HF inflator but swapped the gauge for an oil filled gauge that I can read! This is also verified by a Eez TPMS. Manufacturer specs tires at 80 psi, load and inflation tables spec 74 psi so at the sped 80 I also have a buffer of almost 10% The tires are load range E and max psi is 80.

 

[PoorUB]

Two options, Fill the tires as far as you can, then let the compressor cycle, you might have to blow off some air to get the switch to kick in, and then fill the tires the rest of the way when the tank is nearly full, or swap out the pressure switch with one that has a narrower off/on set points.

 

[MacMcMacmac]

Unplug it. Take off the switch cover. You can usually manually trip it back on with a little trial and error even if it's above the cut in pressure.

 

[gimpyrobb]

I am **** about tire pressure and gauges. I have a HF inflator but swapped the gauge for an oil filled gauge that I can read! This is also verified by a Eez TPMS. Manufacturer specs tires at 80 psi, load and inflation tables spec 74 psi so at the sped 80 I also have a buffer of almost 10% The tires are load range E and max psi is 80.

So you are going by the max psi the tire is rated for, not the recommended psi by the car manufacturer?

"The most accurate way to find your vehicle’s proper tire pressure is to check the manufacturer’s sticker, usually located on the driver-side door jamb, inside the fuel-filler door, or in the glove box. The owner’s manual also lists the recommended pressures for both front and rear tires, and sometimes for heavy loads. Do not rely on the numbers printed on the tire sidewall, as these indicate the maximum pressure the tire can handle, not the recommended operating pressure."

Just an FYI.

 

[jjrbus]

So you are going by the max psi the tire is rated for, not the recommended psi by the car manufacturer?

"The most accurate way to find your vehicle’s proper tire pressure is to check the manufacturer’s sticker, usually located on the driver-side door jamb, inside the fuel-filler door, or in the glove box. The owner’s manual also lists the recommended pressures for both front and rear tires, and sometimes for heavy loads. Do not rely on the numbers printed on the tire sidewall, as these indicate the maximum pressure the tire can handle, not the recommended operating pressure."

Just an FYI.

Max pressure on side wall load range E tire is 80 psi, CYA PSI recommended by RV manufacturer is 80 PSI. Load and inflation table for actual scale weight is 74 psi.