As indicated last weekend Matt took the removed Release Valves home. As their name suggests they are required to release the vacuum within the cylinder to allow a vehicles automatic brakes to be released for shunting or maintenance purposes.

In the evenings he split the valves, most of which put up a struggle as they have not been split for many years.

Once apart, internal components were cleaned up with particular focus on the seal and diaphragm seatings.

Replacement diaphragms and seals were then fitted.

The valves were reassembled and given a protective coat of Hammerite.

Only four of the five valves have received overhaul as the remaining one is the earlier C type with the piston’s ball valve within the release valve rather than the the common E type that has it in the piston it’s self, this will be held separate as will it’s corresponding cylinder as we wish to standardise the components fitted to the fleet.

Paul and Matt on site at Peterborough today. With an aim to overhaul three vacuum cylinders, the first was in exceptional condition inside, having last been split in Feb 1985, it was very quickly overhauled. New piston gland, rolling ring and, dome seals fitted and the cylinder reassembled.

The second one however was in a rather poor condition, needing additional work, having last been split in May 1982.

Although it was eventually reassembled with new seals and is ready to go.
The third selected was in even worse condition, all is possible but unfortunately time was against us and splitting the cylinder was all that was achieved.

The overhauled pair is now ready for transport to Wansford and fitting to two vans, see which next week.