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Gast K704 Service Kit for 71R135 71R142 Rocking Piston Oilless Pump Rebuild KIT. AT258, AT256, AT272, AT329, AF817. Fits All Single Piston Models Starting with 71R1.

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Used  US$39.80
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Product details

Management number 222668573 Release Date 2026/05/04 List Price US$39.80 Model Number 222668573
Category

Gast K704 service kit returns your unit to original factory performance specifications. Recommend for service every 2 years. Kit include 1 x AT258 HEAD O RING 2 x AF817 LEAF VALVE 1 x AT256 CYLINDER O-RING 1 x AT272 CYLINDER Sleeve 1 x AT329 PISTON CUP Does NOT include any other parts, pieces, filters, etc. Fits 71R135-P001B 71R142-P001B 71R142-P001B-D300X 71R142-P001B-D301X 71R142-P075T-D300X All 71R135 models. 1. Disconnect electrical power to pump. 2. Disconnect air supply and vent all air lines to release pressure or vacuum. 3. Mark the orientation of the ports so cover will be reinstalled correctly. 4. Remove screws from the head of the pump. Remove the head of the pump. 5. Mark orientation of valve plate(s). Remove valve plate(s). 6. Remove and discard old cups(s), retainer screws, cylinder O-ring(s), head O-ring(s), valves and valve retainers. 7. Install new cup(s) on rod(s) facing up. 8. Reinstall retainer plates. 9. Apply a thread locking compound to retainer screws. Torque screws to 34-38 in. lbs. 10. Carefully install cylinder(s) over cup(s) at an angle to avoid damaging cup(s). 11. Clean valve plates with water based solvent. Take care to not scratch valve seats. 12. Install valves and valve retainers. Check that the orientation with the ports is correct. 13. Apply a thread locking compound to retainer screws. Torque screws to 10-13 in. lbs. 14. Install cylinder O-ring(s) in the bottom of valve plate(s). 15. Check that the orientation of valve plate(s) with the ports is correct. 16. Install head O-rings in the O-ring grooves on top of valve plate. 17. Reinstall head over valve plate(s) checking that orientation with ports is correct. 18. Torque screws to 50 in. lbs. Check that all external accessories such as relief valves and gauges are not damaged before re-operating product.

  • Kit include 1 x AT258 HEAD O RING 2 x AF817 LEAF VALVE 1 x AT256 CYLINDER O-RING 1 x AT272 CYLINDER Sleeve 1 x AT329 PISTON CUP
  • Does NOT include any other parts, pieces, filters, etc.
Manufacturer DIY Pond Aeration

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