if it's priming up longer than it normally does then the fluid is not getting pressureised as quickly, therefore it's either got a leak or the pump is getting tired or the pressure switch is faulty or any number of that sort of problems

normally this is cuased by the fluid being old and taking longer to compress
it's also caused by the fluid getting too hot from the exhaust and setting thigns off as well
and obviously if the pressure switch starts to fail or one of the other components is having a tough time this could also be a problem

as long as none of the lights illuminate it's not really a problem, the granada takes an age to pump up but once it does it's fine so i think you are worrying baout nothign