GSE Compressor Rebuild Kit
Thank you for acquiring the ZW280 Rebuild Kit.
The Rebuild Kit contains:
2 – Teflon Piston Cups,
2 – Anodized Aluminum Cylinder Sleeves,
4 – Stainless steel reed valves,
4 – Reed valve keepers & screws,
4 – Gaskets,
8 – Cylinder head screws
The installation is simple
The installation of the rebuild kit is very simple. Prior to the installation of the rebuild kit, unplug the compressor and remove to a clean workspace. If the intake filter element has not been cleaned, inspect, clean with mild soap and water as necessary and set aside to dry. If the cylinder head screws are removed with a power drill, turn the torque setting down to prevent gauling or stripping of threads. Scribe a mark on each cylinder head assembly down to the compressor body and position the compressor so that after the cylinder head, pressure plate and stainless steel spacer plates are removed – they may be set flat, upside down for inspection, immediately beside the compressor so that the cylinder head and pressure plate orientations do not become confused during reinstallation. (See Figure 1)
With a hair dryer or heat gun (on low) slightly warm up the protective covers on the end of the compressor and remove them. Warm up the bottom connective screws on the connecting rod and the eccentric on the ends of the motor shaft so they can be removed to expose the inner bearings.
If the screw in the centre of each piston offers abnormally high resistance to removal, heat the head of the screw in the center of each piston, only moderately, as their threads may have been treated with a moderate strength “Loctite” compound. Back the screws out and lift the screw, the plate on the top of the piston, the Teflon piston cup, and the replaceable cylinder sleeve out together if the cylinders haven’t come out with the cylinder heads.
Inspect for damage to the piston head. Some scoring of the edge of the piston head is allowable and shouldn’t hurt the new Teflon piston cup but use your personal judgement. If damage is too severe contact us and acquire a new piston.
With a heat gun or hair dryer warm the ears of the protective plastic covers on each end of the compressor and gently pry the covers off. With a pair of narrow flat bladed screwdrivers gently pry the fans off each end of the compressor exposing the bottom end of the con rods and the eccentrics. Moderately warm the eccentrics and the bottoms of the con rods and remove
To Rebuild:
1. Place the new Teflon piston cups on top of the connecting rods. Replace the pistons top plates and screws. Be careful to align the aligning detents with the corresponding holes in the tops of the pistons. No more than 12-14 inch pounds of torque should be required. If Loctite or equivalent is used, no greater than medium strength should be used.
2. With a grease nipple fitted with a hypodermic syringe needle put one shot of premium quality grease in each of the bearings that the motor is running on as well as the two bearings on the eccentrics. This simple operation can as much as double the life of the compressor.
3. Gently place the con rods, piston cups and cylinders over the pistons back into the body of the compressor. Work the piston cups gently down into the cylinders ensuring that the base of the cup is flat around the top of the piston.
4. Replace the eccentrics on the ends of the motor drive shaft and retighten (being careful not to over torque). Realign the eccentric location with the scribe marks that you made on the ends of the shaft and reinstall.
5. Remove and replace the old seals that seal between the top of the cylinders and the underside of the pressure plates.
6. Replace the reed valves and reed valve keeper plates on both sides of the pressure plate being careful not to get the plates orientation confused. Take great care to align the reed valves and keeper plates perfectly over the exhaust and inlet parts on the pressure plate. To put it into perspective, your compressor should have run for at least 2 years in continuous duty. In that time the reed valves should have cycled over 1.7 billion times. They are very high quality spring steel and they may look “OK” and they may be “OK” but if they fail in the next two years your investment in time and the service kit are forfeit. Put the new ones in and do your best to align them and the keeper plates accurately.
7. Replace the stainless steel spacers around the top of the cylinders in the body of the compressor with the cylinder head screw holes aligned with those in the compressor body.
8. Replace the pressure plates on the top of the cylinders making certain that the O-Ring seals seated in the underside of the pressure plate mate perfectly with the top of the new cylinder sleeves and that they won’t be crimped when the cylinder head is tightened down – no sealant or gasket compound should be required for any seals in these compressors. Ensure orientation is correct and that the reed valve screw heads will not contact the top of the piston.
9. Replace the “Figure 8” O-Rings in the cylinder head that seal the cylinder head’s inlet side from the pressure or outlet side, ensuring that they won’t be crimped when placed back on the pressure plate.
10. Carefully replace the cylinder heads back on the pressure plates.
11. Screw the new cylinder head screws in, in a diagonal pattern from one another till they just seat evenly.
12. Remove a fan guard from one end of the compressor and gently rotate the compressors drive shaft a few times to ensure that the rotation is smooth, that compression is evident and that there is no binding through the rotations.
13. If there is binding gently remove the cylinder heads and pressure plates to re-inspect the orientation of the pressure plates and cylinder heads. If there is no binding, tighten down the cylinder heads’ screws in a diagonal pattern in two stages to finish as evenly tightened to a firm but not excessive hand tight. You will know when to quit when you feel the screws bottom out.
14. Turn the fan once again to verify that rotation is smooth and compression is evident. These are “medical specification” compressors and manufacturing tolerances are so exact that roughness in the rotation may not be experienced till final tightening. There should be NO roughness so please check rotation again after final tightening.
15. If rotation and compression are normal, re-thread the 1/4” galvanized header ¼ turn brass ball valve and 0-60 psi glycerine filled gauge assembly into the compressors exhaust port with the ¼ turn ball valve in the “OPEN” position.
16. If the intake filter element is dry, reinstall it.
17. Plug the compressor in and both listen and feel for abnormal sounds or vibrations. If operation is normal, allow the compressor to run open ended for five minutes to warm up. If operation is normal, slowly close the brass ball valve and read pressure on the gauge. If the gauge is accurate, close the valve for a second or less. The pressure relief valve should open at approximately 40 psi (280 kpa). Immediately open the ball valve and allow the compressor to run for a minute or so before unplugging it.
18. If the compressor is operating normally mark the date of the rebuild on the unit and place it back into service.
If you have questions or concerns contact us immediately for assistance.
With thanks – Fresh Water Treatment Systems Ltd.