Update. If you take the hand wheel / knob off and put a spanner on the shaft and undo it firmly the splindle, o ring and washer will come out. The splindle is sealed by and o ring between 2 brass washers with the top peened over. Its a bad design and the heat is sure to make the o ring hard and leak after a while.The OEM design has a separate screw in gland so it can be nipped up or changed. Craddocks list the OEM 2 piece type for £20 + £5 P&P when the cheap one piece type is £15 inc post on ebay. Being a natural cynic I phoned Craddocks and asked the person who answered to put up the part (88G588L) on their website, look at the photo, confirm that it has 2 parts with a removable gland nut, confirm that the one of their stock looks like that. Yes to all questions and they even went away for a while to check (or so they said). So I order one for £25 and what turns up? Yep the £15 one peice rubbish one. So I phone Craddocks again expecting something along the lines of "honest mistake, we'll send the right one". But no, what I get is "the small print says it may not look like the picture" and "we haven't had that OEM type for some time.." After I reminded them that they record their calls and I had logged the time and date of the call in which they confirmed the type they stocked looked "exactly" like the picture they agreed a full refund inc postage. But it still leaves open the question as to who in Craddocks you can trust " yes it looks exactly like that sir" or " no we haven't had those for a while..". I got an used OEM 2 part one off ebay in great nick for £13 inc post so its all ended well but I still have to complete an online form to get my refund, and pack and post the wrong item so its a pain that could all have been avoided.