Shurflo 4008 Revolution Water Pump

12V pump3.0 GPMVan water

Overview

The 4008 is a common RV demand pump; the quality of the install decides whether it feels civilized or irritating.

On paper, the useful part is simple: a 12V diaphragm pump that moves up to 3.0 GPM, shuts off around 55 psi, and restarts as line pressure drops. In a van, the real question is whether you can reach the strainer, shut the pump off quickly, find leaks, and drain the system before a freeze.

The pump belongs close to the fresh tank on an individual fused circuit, with a strainer before the inlet and flexible hose on both sides so vibration does not turn the cabinet into an amplifier. Rigid pipe directly at the pump is how a small convenience upgrade becomes noisy.

I would treat this as a system part, not a shopping-cart part. The pump, tank, fittings, hose, switch, fuse, faucet, gray-water path, and winterizing plan all need to make sense together.

Best forCamper sinks, trailer water systems, and wash stations where stored water needs steady pressure and the pump can remain accessible.

Not forUltra-simple kits where gravity flow works, or cramped cabinets where you cannot inspect fittings, clean a strainer, or drain the pump.

The pump is not the whole water system. It is the moving part that reveals whether the rest of the water system was planned.

Where to Buy

Shurflo 4008 Revolution Water Pump

A 12V demand pump for small RV, trailer, and campervan fresh-water systems when the install includes proper filtering, wiring, and service access.

Direct product link for current details and pricing.

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Quick Read

Role

Pressurized water

Best Fit

Small pressurized sink or rinse systems with a fresh tank, gray-water plan, and accessible cabinet space

Why It Works

The built-in pressure switch lets the pump run on demand instead of needing a separate faucet routine

Skip If

You cannot add a strainer, fused circuit, leak access, or freeze-drain path without tearing the build apart

At a Glance

Flow

Rated up to 3.0 GPM at open flow; actual faucet flow drops as pressure and restrictions rise.

Pressure

Factory control is around 55 psi shutoff and 40 psi restart on the 4008-101 model.

Circuit

Plan a dedicated fused 12V circuit; Pentair lists a 10A recommended fuse and a 15A switch.

Inlet

A strainer before the pump is not optional if you want the valves and diaphragm to stay clean.

Hose

Use flexible high-pressure hose at both ports to reduce vibration and protect fittings.

Duty

This is an intermittent-duty fresh-water pump, not a continuous-transfer pump.

System Layout

A sensible simple run is fresh tank, tank shutoff, inlet strainer, short flexible hose, pump, another flexible hose, then the faucet or controlled branch. Keep the pump low enough to prime easily, close enough to the tank to avoid a long suction run, and turned so the strainer bowl and pump head can be reached later.

If a drinking-water filter is part of the build, do not starve the pump by putting a restrictive filter on the inlet side. Give filters their own planned branch or place them where flow restriction will not make the pump chatter.

Install Checks

Before Power

Confirm polarity, fuse size, switch rating, wire gauge, and a clean ground before the first test.

First Fill

Run the pump with doors open and a dry towel under the fittings so even a slow seep shows up.

Noise

If the pump sounds harsh, look for rigid pipe, a flexible cabinet panel, overtightened feet, or a restricted inlet.

Freeze Plan

Drain the tank, lines, pump body, and low points before freezing weather; frozen water can ruin the pump.

My Notes

This is a system part. Buying the pump is easy; routing, filtering, wiring, and draining it cleanly is the work. A loud, buried, impossible-to-service pump gets old fast.

Put the manual pump switch somewhere obvious so it can be shut off when the van is unattended.
Leave enough room to clean the inlet strainer without removing the cabinet.
Do the boring leak test before gear, drawers, and insulation hide the fittings.
If the pump cycles with every tiny faucet movement, look for restrictions, air, leaks, or a clogged strainer before blaming the pump.

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