i just take the spring out and shim it with small washers. test the pressure with a air hose.
before taking it apart do some pressure tests on the pump for reference. set the air regulator to zero, apply air hose to bypass passage and crank up the pressure until it bypasses. add washers until you are satified. do not go overboard! tom

Inliner Member 1716
65 Chevelle Wagon and 41 Hudson Pickup
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