Can raincoat waterproofing be redone or rejuvenated?

I have a 4 year old Patagonia raincoat w/a separate down liner. It’s still great, but I’ve noticed that rain doesn’t bead up any more - it gets absorbed. As long as I don’t stay out more than an hour, I stay dry. I’ve machine washed & dried - the machine drying is supposed to help maintain the water resistance. I’d hate to replace it, but I need to stay dry! Ideas? Thanks.