coolant pressure on 1996 Chevrolet Lumina

How long should coolant pressure hold when testing it with a pump-up pressure tester? My system is a 15 psi. I'm losing coolant very slowly and the pressure fades off from 15 psi to 10 psi over a half hour. Should it?

Asked by for the 1996 Chevrolet Lumina
1 answer 1 comment
That may just be normal leakage of the tool so check that first. My Stant pressure tester would hold pressure for an hour without dropping but two other fellows at work see their pressure tester loose 5 psi in i/2 hour.
Thanks for the answer. I suspect that's why mine bleeds down too. I replaced an upper radiator hose that was pretty soft so I'm hoping it stops losing coolant now.