Domestic fridge/freezer pressures

Hi All.
My normal job is in installation of splits/add-ons using R22 and R410.
My fridge and freezers at home are giving me trouble.
1. Freezer. R143. Cabinet temperature slowing decreasing - currently 5.4 C. Fitted piercing valve on suction line. Pressure about 3 psi. What should the running pressure be?

2. Fridge/freezer in garage. R12. Lowest cabinet temperatures are 4.9 and - 9 C. Want to add some SP34E. What pressure should I be expecting on suction?

3. Chest freezer. R12. Lowest temperature - 13 C. Again to top up with SP34E. What is an ideal suction pressure.

Many thanks

Chris Siers

chris , how long have you been working on a/c- fridge ? do you normally guess the temp or have you got any comparitors to see what the psi is temp= happy guessing

dont know about manufacturers now,low temp stuff was 0 psi or less,westinghouse fridges where similar.
probably not handling the heat chris