Hitachi 236464 manual Troubleshooting Chart, Its stroke keep the wet-cup 1/3 filled with a

PROBLEM

CAUSE

SOLUTION

The pump fails to oper-

Valves are closed or clogged.

Clear the air line; increase the air supply.

ate.

Check that the valves are open.

The fluid hose or gun is obstructed.

Clear the hose or gun*;

use a hose with a larger ID.

Fluid has dried on the displacement rod.

Clean the rod; always stop the pump at the bottom

of its stroke; keep the wet-cup 1/3 filled with a

compatible solvent.

Air motor parts are dirty, worn, or dam-

Clean or repair the air motor;

aged.

see the separate motor manual.

The

pump

operates,

The air line is restricted or the air supply

Clear the air line; increase the air supply.

but the output is low on

is inadequate. Valves are closed or

Check that the valves are open.

both strokes.

clogged.

The fluid hose or gun is obstructed;

Clear the hose or gun*;

the fluid hose ID is too small.

use a hose with a larger ID.

Worn packings in the displacement

Replace the packings.

pump.

Air motor parts are dirty, worn, or dam-

Clean or repair the air motor;

aged.

see the separate motor manual.

Held open or worn intake valve.

Clear or service the intake valve.

The

pump

operates,

Held open or worn intake valve.

Clear or service the intake valve.

but the output is low on

the downstroke.

The

pump

operates,

Held open or worn piston valve

Clear the piston valve; replace the packings.

but the output is low on

or packings.

the upstroke.

The

pump’s

speed is

The fluid supply is exhausted.

Refill the supply and prime the pump.

erratic or accelerated.

Held open or worn piston valve

Clear the piston valve; replace the packings.

or packings.

Held open or worn intake valve.

Clear or service the intake valve.