My Ridgid gas powered wheelbarrow, 5.5hp 9 gal air compressor bought at home depot, shaking?

It starts up runs fine, when i disconnect pump exhaust from the unloader valve when hooked up runs to up to 100psi, starts to shake a lot.

Then when it reaches max psi at 150 it dies and  the air output gauge reads 0 psi , no pressure but tank gauge says its maxed at 150psi?

A number of issues here on your Ridgid wheelbarrow type air compressor.

I took a look at the manual for model GP90135, which is the same as or similar to yours. Interesting to see that this round of Ridgid air compressors is made by Campbell Hausfeld.

As far as the shaking goes, make sure all mounts are secure, and watch (carefully) the action of the drive belt as the air pressure reaches the “shaking point”. It sounds to me like it might be belt misalignment causing part of this.

When cut out pressure is reached, the unloader is supposed to allow the gas motor to idle until the tank pressure drops to cut in. If the motor dies on cut out pressure, throttle adjustment may be out of whack.

If your air tank gauge shows 150 PSI and the regulator gauge shows zero, either the regulator gauge is broken, or you have turned down the pressure setting to the point where the regulator, which is also an on/off valve on some models, is turned off. It can’t read pressure as none is getting to the gauge.


Progress, but still inoperable.
by: Mark

Thanks for the input.

Took motor to repair shop. Someone has put a start capacitor on the run side of the windings. He installed a run capacitor, started it and the amps when from about 26 to 6.5.

Took home, put the motor on and it started right up and shut off at 150.

Bled off some air and the motor would not restart.

Determined had back pressure on cylinder. Took check valve apart and cleaned even though not very dirty.

Got to looking for bleeder valve as described in the manual and it was not there. Someone had changed the pressure switch out eliminating the required bleeder valve.

Now I have to locate a new pressure switch with bleeder valve.

The unit is a RIDGID OF45150.


Ridgid OF45150 air compressor
Ridgid OF45150 air compressor

By bleeder valve I take it you mean the UNLOADER VALVE, Mark?

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