Hi,
It is possible to repair the leaking filter head quite easily.
Usually the problem lies with either the hose end connectors themselves or the hose connection unit.
If its the hose end connectors you'll usually see water on top of the filter housing itself and the best course of action is to first check for good seals to the hosing and if thats good to replace the hose end connectors themselves which are about a tenner a pair. I've tried dismantling them but its very tricky and the lugs holding the screw ring on snap off easily.
However more often the case is that the connection unit itself is the problem as this has a bit of an inherent design problem associated with it. If this is leaking then the water trickles down the outside of the canister so that it appears to be a faulty canister filter seal but there is an overflow channel which the water follows and it comes out underneath the canister clips.
The solution to this problem is to dismantle the hose connector unit by undoing the 4 screws underneath it, take it apart noting how it has to go back together paying particular attention to the sealing rings and the ball valves. Its quite self explanatory once you've seen it apart. Anyway on the plastic angled tails that the hose end connectors screw onto there is a two raised ridges with a gap between them. IMO there should have been a seal fitted in this gap and its been omitted for some reason as this is were the unit leaks from. What I do is to get some standard PTFE tape and wrap it round and round very tightly in that gap until it's few mm proud of the raised plastic ridges then reassemble the unit which will now need a little force to do and screw everything back together. Its worked for me on more than one occation.
Hope this helps.
Regards, Chris.
