Putting shee back together and have a leak from the pro design cool head where water pump tube goes---the tube that runs up between the intakes. I have replaced the tube and the cool head orings but the kit does not come with the oring for the rear water tube. It has two allens--took it apart the oring is shot. Any clue what size it is or if anyone else has had this problem. Tried some orings from work but they are to fat for the grove it fits in--still leaks. Will any oring from Ace hardware work--they have a bunch in the plumbing dept but not sure if they will hold up. Thanks for any input