I have a leak at the low side Schrader valve on a 2001 Accord EX 4-Cyl. What should the low and high side AC line pressure readings be at idle using R-134a? Plan to change the valve, evacuate the system and recharge this weekend. Does anyone have a manual with oil and refrigerant amounts? Also any other tips I should look far. I have done this before on a Chevrolet R-12 but not on a R-134a.