MK1 - MK2 Piston Seal Kit

MK1 and MK2 Piston Seal Kit (not for use in the MK3 or MK4 pumps).
A kit of 3 replacement piston seals. The classic symptom of a problem with this seal is resistance on the upstroke and tendency to recoil back downwards. The piston seal is the workhorse of the pump and it's life can be dramatically shortened by overheating and a lack of lubrication. To maximise the life of this seal please follow the advice on pumping and lubrication in our instructions.