#31556 Unloader Repair Kit 67DX39G1l Pump.
Refer To Service Manual For Service Procedure.
See photo with parts breakdown.
https://www.catpumps.com/sites/default/files/2020-08/67DX39G1I_H_0.pdf
https://www.catpumps.com/sites/default/files/products/pdfs/31398A_MAN_67DX.pdf
