Hayward SPX1600Z4 Housing Cap Screw

The Hayward SPX1600Z4 is the housing cap screw used on the Super Pump and Super II and on a number of other Hayward and Jandy Laars products. It is the genuine Hayward part, given as 3/8-16 x 2.

Where it is used

Hayward lists it under the Super Pump SP1600, SP1600X, SP2600 and SP2600X, and the Super II SP3000 and SP3000X including the Heldor EZ-Flo. The same fastener is carried under the Max-Flo 1800 and 2800, the Leslie’s Hydramax II, the Super Spa SP-3500, an HRP sand filter group and several Jandy Laars Series 2 and Lite heater diagrams. That is a broad list for one screw, so measure the one you are replacing against the 3/8-16 x 2 size rather than ordering on the model name alone.

The practical problem

These screws sit in a wet, chlorinated environment for years and then have to come out during a service. Many do not, or they come out with the head chewed. Work them with penetrating oil and time rather than force, because a screw snapped off inside a housing turns a routine job into an extraction. When you do get them out, it is usually worth replacing the whole set: they have all seen the same water and the same heat.