Had a look at the Twose hedgetrimmer we bought 11 months ago, its just been hitched on and the hydraulic tank filler breather soon made a messy film over the tank, something we had noticed back in the spring. Knowing its getting near the end of its warranty period I was just going to look the filler over, clean it and see if there was anything that needed emailing the dealer about.

The filler is made by Parker and we also have two on the Bateman RB26 both which have given no problem so it seemed odd to be leaking like this.

The filler is a bit flimsy plastic unlike the old traditional UCC steel type. Its easy to pop the cap apart to reveal the foam filter which sits in a recess- this was full right up with the foam filter just sat there in this circular ring of oil. Nothing seemed to be wrong that may be causing the weeping so I'm banking on it being a case where there is a lot of oil flowing in and out of the tank and the short filler neck makes the filler/breather fairly close to the oil level. (On the bateman it is just the opposite- the oil flow is a lot less and the max level to filler is a lot further.

Once it was all apart after checking the imbedded oring that seals the cap to the base I then studied the way the air moved through the cap, it then dawned that the designers had made the recess the foam filter sits in the same height so if the foam becomes soaked in oil as in our case, it will flow over both inner and outer edges of the recess- one way back into the tank the other out through the vent holes and all over the tank. Looking at the vent holes around the outside of the cap it looked very difficult for water to get into the cap unless it was totally immersed in water so thinking that its very unlikely to get water ingress I decided to modify the inner edge of the foams groove by drilling four 3mm holes about mid-way up so its possible for the oil to drain back into the tank.

Heres it shows the slots in the fillers base on the left (the lower part of the cap is in place to show where it sits) and the line on the right shows how the two sides of the foam filters slot are both the same height. The 2nd image shows the 4 drainage holes.

Sent all this off to Twose to see if they are happy with this or want to do something else, meanwhile after a couple of hours hard hedge thrashing it seems to of done the trick as there is very little, if not zero leakage from the breather now