How to service or repair the Leafield Marine A7 or B7 inflatable boat valve

After a few years of faithful service, the rubber diaphragm on a RIB/Inflatable Boat Leafield Marine A7 or B7 inflation valve can fail as either the rubber material becomes brittle and fails to ‘seat’ properly within the inflation valve, or the spring or plastic diaphragm spindle can fail. Replacing the Leafield Marine A7 or B7 inflation valve diaphragm is a straightforward job and the service kits are available from ribstore.

To service your Leafield Marine A7 or B7 valve, you will need:

The ribstore A7/B7 service kit, which contains a new valve spindle, spring and rubber diaphragm (1 kit per valve) see: https://www.ribstore.co.uk/products/leafield-a7-b7-rib-inflation-valve-service-kit
For A7 - a socket or large pair of grips + cloth to cover wrench jaws and clean components
For B7 - a valve wrench spanner see: https://www.ribstore.co.uk/products/a6-b7-relief-valve-spanner
Pair of long nosed pliers
A small length of masking tape

Refer to diagram below of the valve assembly to familiarise yourself with the inflation valve and its components, before you start the job.

Lock the valve spindle in the open position by pushing-in and twisting anti- clockwise the valve spindle to deflate the inflatable boat collar or tube.
Keep the tube as flat as possible to avoid losing the valve part inside the tube from getting lost. It can be very difficult to retrieve if it falls inside the tube.
Maintain a grip on the inner valve assembly through the inflatable collar or tube fabric to ensure that the inner assembly does not fall loose inside the tube. Unscrewing anti-clockwise remove the nut/outer valve assembly from the inner assembly (plus washer on the A7). For A7 - use a socket/spanner or a large pair of grips (use a cloth to cover the jaws of the grips to prevent damage to the plastic valve). For B7 - use a B7 spanner wrench. Tie some strong cotton thread or string around the screw thread of the inner valve assembly and secure the other end of the string whilst you dismantle the valve. Put a piece of masking tape over the depressed spindle to stop it falling into the tube later. Whilst continuing to grip the inner valve assembly through the inflatable tube fabric, push the inner part of the valve inside the tube and carefully rotate the inflation valve around so you now see the rear of the inner-valve assembly through the valve aperture in the inflatable collar or tube wall.
You can now unscrew the black rubber cup diaphragm from the spindle by using a pair of long nosed pliers to grip the rubber diaphragm and unscrewing it anti-clockwise. Once the diaphragm has been unscrewed the inflation valve can be turned around again. Remove the masking tape and the old spindle and spring. Ensure all surfaces and valve components are clean and free from dirt or objects that could prevent the valve from sealing once re-assembled.
Insert the new spindle and spring into the valve, push and turn to lock the spindle in the open position and put a second piece of masking tape over the valve opening to prevent the spindle from falling out. Once again carefully turn the inflatable boat valve around within the inflatable collar or tube so that you can see the rear of the valve assembly, screw the new black rubber diaphragm onto the spindle – finger tight only. Do not use any tools or you may break the spindle.
Take care not to cross thread or damage the new cup diaphragm.
Carefully turn the inner valve assembly back round once again and pull the thread of the inflation valve body back through the aperture in the tube wall. Remove the masking tape and screw back on the nut/outer-valve assembly.
Inflate the tube and check the valve is airtight.