I noticed yesterday that I was starting to lose air in the rear segment, some quick investigating with a spray bottle and soap solution confirms that I've got a leak at the rubber gasket underneath my overpressure valve. It looks like this is a Halkey Roberts style valve and the user manual shows that this might just unscrew and easily be replaced with a new valve and gasket.
However, the manual shows a hex nut on the front of the valve and mine is round with only a few tiny tabs that the red cover caps screw onto. The manual shows part number 3862 for a replacement and I think I've found one on ebay, but I'm not 100% sure if I've got the right part. I also am not sure what the best way to get the valve in and out is. I'm assuming there's some sort of tool but my searching turned up a lot of different tools that seem to be designed for other variations of the HR valve.
Anyone done this job before, and any tips or suggestions?