A 12V soft wash pump with a drip coming from the seam where the pump head meets the motor looks like a failed seal. Most of the time it is not. The screws that clamp the head down have relaxed a little, and the fix is a small screwdriver and about two minutes. In the video we have two pumps on the bench: a customer's Remco 7 GPM dual control that came in with problems, and a Remco 5.3 straight out of the box that had never been hooked up. Both of them needed it.
Why the head screws loosen
The pump head on a Remco is polypropylene and the seal between the head and the motor housing is a rubber (Viton) seal. Both of those materials flex. The pump gets assembled at the factory, sits on a shelf at Remco, sits on a shelf at a distributor, sits in a box on a truck, and the whole time the plastic and rubber are slowly relaxing under the clamp load. By the time you put it into service, the screws are not as tight as they were the day it was assembled. Add the vibration of a pump running against a bleach mix all day and you have a weep.
That is why the brand-new 5.3 in the video turned. It was not defective. It was normal.
What you need
The head screws take a T20 Torx bit. Use a hand screwdriver, not an impact driver. You are not trying to crush anything; you are taking up the slack that the plastic and rubber gave back. An impact on a polypropylene head is how you end up buying a new pump head.
How to do it
Go around the head one screw at a time and give each one a gentle snug. Watch the screwdriver as you turn it: on the pumps in the video every screw moved somewhere between a sixteenth and an eighth of a turn before it seated. That is the whole adjustment. When the screw stops with light hand pressure, stop. Then flip the pump over and do the screws on the other side the same way.
Remco publishes a torque spec for these, and if you have a small torque driver you can chase it. In practice, light hand pressure on a T20 driver until the screw stops is what we do, and it is what has worked on hundreds of pumps. The failure mode to avoid is going past snug, because an over-torqued screw in polypropylene strips or cracks the boss and now you really do have a bad head.
Do it before the first run, not after the first leak
Every pump that goes onto one of our builds gets this done on the bench before it is plumbed, whether it is a bare pump or one of our plate-mounted Remco assemblies. If you are buying a pump and installing it yourself, do the same thing. It is much easier with the pump in your hand than with it bolted into a skid behind a mixer.
If you already have a pump in service and it has never been checked, check it at the next rinse. It is a two-minute job on the rig.
If it still leaks after snugging
Then it is time to look harder. A pump that has been run dry, run hot, or left full of bleach overnight for a season can have a genuinely damaged diaphragm or seal, and no amount of screw tightening fixes that. The head assembly on the 7 GPM FatBoy is a bolt-on replacement. Also check the obvious: a leak at a fitting or a cracked quick-connect can run down the body and look like a head leak. Remco's quick-connect hose barbs are cheap and worth swapping on suspicion.
The habit that matters more than any of this is rinsing the pump after every job, not once at the end of the day. We go into why in 12V Soft Wash Pump Setup: Why Most of Them Die Early.
Parts mentioned
- Remco 5.3 GPM 12V soft wash pump
- Remco 7 GPM 12V soft wash pump
- Remco 5500 / FatBoy series screw kit — all ten head screws, if any are stripped or missing
- Remco FatBoy 7 GPM pump head assembly
- Remco pressure switch, 5500 series and 7 GPM pressure switch and relay
- All 12V soft wash pumps and parts
Further reading
- 12V Soft Wash Pump Setup: Why Most of Them Die Early
- Remco 5.3 GPM vs 7 GPM Soft Wash Pump: We Tested the Distance
- Pressure Washing Rig Maintenance Guide: Skids, Trailers, and Vans
Pump still leaking, or not sure what you are looking at? Call the shop at 503-403-6185 (landline, no texts), Monday through Thursday, 8am to 4pm, or bring it by 13896 S Fir St Suite B in Oregon City, Oregon. We work on these every day.
