Charged the A/C system... the high pressure lines are showing over 400 on the pressure. what is the problem

There really isn't too much to the entire system. You have the pump on the front of the motor, attached to it are the high pressure line and the low pressure return line. The low pressure line attaches to the reservoir and the high pressure line attaches to the pump. They both go to the rack-N-pinion. The high pressure line runs to the front of the car and has a big loop to aid in cooling the fluid.

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Typically the the low pressure/suction line is a bigger pipe/tube, as far as location it depends on the car. The bigger AC line is almost 99 percent of the low pressure. Usually on the cap it will say most of the times to there is a different hydraulic fitting for the low and high side. Most cars I have seen have a little tag that will say suction or low pressure line, and or discharge high pressure.

If you are re charging the gas, always use the low pressure side of the system.

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_54ae41aaaffbab00

LOW PRESSURE SIDE IS THE SUCTION CHARGE SIDE WILL BE FROM AC COMPRESSOR REFRIGERANT LINE TO THE ACCUMULATOR OR DRIER TO THE EVAPORATOR IN THE FIRE WALL THE AC COMPRESSOR LINE TO THE CONDENSOR IS THE HIGH PRESSURE SIDE YOUR DISCHARGE SIDE. DONT DONT TRY CHARGING AC SYSTEM AT THE HIGH PRESSURE SIDE. CHARGE AT THE LOW PRESSURE SIDE.

You never ever charge any refrigerant system in the
world from the high side

Always the low side,as you want to add it in a gas form

If you invert the can & charge hi side ,liquid ref will

ruin the compressor, as it can't compress a liquid

You may have created an over charged condition and at this point the a/c compressor will cut off on high head pressures. This can be verified by installing gauges to the systems high and low side service taps and reading the pressures.An overcharged system will start the compressor briefly but soon cuts off once pressure goes to 350 - 400 lbs on the high side. Acceptable pressures for this system should be no greater than 250 high and low suction should drop to 40-50 psi.You might recover the charge and evacuate the system,then try bringing the charge back to proper level.A sight glass in the reciever drier really helps determining proper fill.Once all bubbles have dissipated from the sight glass during charging ,one should stop at that point to avoid overfilling.Too much freon is worse than a low charge especially in hot ambient conditions....

low pressure is coming from the dryer, the canister on the passenger side of fire wall. The high side is next to compressor.

Basic AC system consists of Compressor pump (on engine), Condenser (front grill with radiator) and Evaporator (Firewall). Pump has two ports output (high pressure) and return (low pressure). Follow lines from pump. High side is usually between pump and condenser. Follow lines and find second port this will be low side (refill) port. Paint or replace port caps (red high, blue low). Also, refrigerant in system determines port size (R12 or R34).

there are 2 ports one for low pressure and one for high pressure. the low pressure is bigger in diameter and is usually close to the dryer and or fender and firewall. the high pressure is near the condensor on the fron of the vehicle. if there are caps for the ports low will be blue and high will be red. low side pressure should be 35-50 psi and high pressure should be 135-150 psi

There are two A/C refrigerant lines. The small line is your high pressure line and the larger line is your low pressure line.
Start at the fire wall and follow the "large " low pressure line to the compressor. The low pressure charge port will be some where on that line.
DO NOT try to recharge on the high pressure side ( small line )
Good luck, let me know.
Regards,