Autotrol 1001404 255 O-Ring Group: Interstage (Between Top/Bottom Plates)

This is the genuine-spec Autotrol 1001404 interstage O-ring group for 255-series softener valves, a set of six O-rings that seal between the top and bottom plates of the piston and spacer stack inside the valve body. Search terms like Autotrol 255 valve leaking, 255 valve weeping between plates, or Autotrol interstage O-ring kit 1001404 usually point straight to this seal set reaching the end of its service life. It's a cheap, quick fix over a full valve replacement, and it's in stock at WrekinWater.

Technical specifications

Symptoms that mean you need this part

• Water weeping or leaking from between the top and bottom plates of the 255 valve body
• Damp or dripping around the valve during service or regeneration cycles
• Loss of pressure or reduced flow suggesting internal bypass past worn seals
• Routine service/rebuild of an Autotrol 255 valve where original O-rings have hardened or perished with age

Why it fails / why it matters

Inside the Autotrol 255 valve, the top and bottom plates clamp around a stack of pistons and spacers, and this interstage O-ring group is what keeps that joint watertight under repeated cycling. Rubber O-rings harden, take a compression set, or develop surface nicks over years of regeneration cycles and exposure to treated mains water, and once that happens the seal between the plates weeps rather than holds, which shows up as visible leaking from the valve body rather than any fault with softening performance itself. Because the O-rings sit between structural plates rather than on a moving shaft, wear is usually a slow, age-related failure rather than sudden damage.

Why buy this from WrekinWater

WrekinWater supplies this O-ring group as a genuine-spec match for the Autotrol 255 valve, so installers and DIY customers repairing a leaking valve get the correct six-ring set rather than a generic assortment that may not seal properly. With more than 50,000 customers served over 15 years, an Excellent Trustpilot rating, and daily experience fitting Autotrol, Fleck, Clack and Kinetico parts from its Bettisfield, Shropshire base, WrekinWater is well placed to confirm this is the right O-ring group before you strip down the valve.

How to fit it

1. Isolate the softener and relieve system pressure before removing the control valve.
2. Separate the valve's top plate from the bottom plate/spacer stack, keeping components in order as you go.
3. Remove the old, hardened O-rings from their grooves, taking care not to scratch the plate or spacer sealing faces.
4. Clean the grooves and sealing faces thoroughly, checking the plastic plates for cracks or wear that could stop a new seal holding.
5. Fit the new O-rings into their correct positions, lightly lubricating each with silicone grease to ease reassembly and protect the rubber.
6. Reassemble the plate and spacer stack, refit the valve, restore water pressure, and check the joint carefully for leaks before returning the softener to service.