Radiator cap markings Jul 22, 2020 18:40:03 GMT Quote Select PostDeselect PostLink to PostMemberGive GiftBack to Top Post by fredinireland on Jul 22, 2020 18:40:03 GMT Can anyone please tell me what pressure rating the Nanni T4.390 rad cap has? Mine is split on the brass disc. The markings are TH21 06 1000 which means nothing to me.Cheers