Max A/C PSI

Hey there, I wanted to make sure my air conditioner system was fully charged, as well as my grandfathers system. I was wondering if anyone knew the max psi you can safely have in the system, before it puts too much strain on the compressor. I'm assuming somewhere around 40? He also has a crv, but I'll post this question in that forum too. Also, I've never had the air conditioning system fully serviced, and was wondering if it would be good to do a full flush and then a recharge.

Anyway, here are the specs:
Mine: 98 Accord
His: 89 Accord and a 00/01 CRV...
Any help would be greatly appreciated. Thanks.

If you are using R12, keep it at 30 psi. If you are using R134A, keep it at 45. Anything above and you are overcharged. BTW these numbers are for an ambient temp of 80F.