How do you check to see if the high side is leaking back into the low side on a scroll compressor suction pressure is 90psi R-22 suction line is warm but not hot

That's 2 psi on the suction side of the compressor, which should be about -10 degrees. I suspect the high pressure side will be the 140 psi. If you need to add freon (134), you have a leak and it needs to be fixed.

First check if condenser motor is running, secondary check if condenser coils are clean. If its commercial refrigerator it might have Low pressure switch and High pressure, if pressure of freon is to low on suction side it will shut power to compressor, same with high pressure switch - but thats commercial refrigeration. If it residential fridge and coils clean and fan is on - try to install 3n1 hard start kit, here is my video that might help You.

Ok, basic refrigeration here. The 'high side' contains the high pressure vapor leaving the compressor and going to the condensor to condense into a high pressure liquid. The 'low side' contains low pressure refrigerant vapor within the evaporator and the suction line back to the compressor. The same amount of vapor has to return to the compressor as left the compressor. So thinking about pressure solves the problem....High pressure equals small line...
Low pressure equals larger line. The low pressure vapor will fill a larger space than high pressure vapor so it has to travel in a larger line. The suction side is the bigger of the two and if the unit is functioning, it will be the one cooler to the touch.

Though this is basically correct in theory, it is not a totally perfect way to descsribe an answer to your question, but it was fun to try.

If your running 134 a your short of gas
if your running 404a your short of gas
check the super heat it should be 5 ktd

Did you pull a vacuum from the high side first, then continue on through the low side ?

1.Recover refrigerant from system

2.Remove suction and discharge lines

3.Remove electrical components

4.Remove old compressor

5.Install new compressor

6.Install electrical components

7.Install suction and liquid lines

8.Remove old drier and install new one

9.Connect gauges and evacuate from both high and low sides to at least 500 microns

10.Charge system and check for leaks

Hi,
If you are running that unit with a scroll compressor and a high load then 90 is not that high and you probably are just low on charge...if you were leaking or crossing over the pressure would be much higher then that...
The only other possibilty would be that you are way over charged, but then you should be hearing a rattle in the compressoras the liquid would be running through it...

heatman101

the tracer is the same as the ESCORT, right?? TRY THIS--I WORK ON PLENTY OF ESCORTS--LOOK UNDER THE AIR CLEANER/CONE ASSEMBLY--THERE WILL BE A BLACK METAL BOX(FULL OF RELAYS) ONE OF WHICH IS THE A/C RELAY--TRY TAPPING ON IT WITH A LONG SCREWDRIVER OR SOMETHING SIMILAR WHILE U HAVE THE A/C ON. IF THE A/C SUDDENLY STARTS WORKING U NEED TO GET A NEW RELAY BOX(I THINK ITS CALLED A GEM MODULE) i do have a question- does the blower motor work?? how do u know the compressor is good??do you have 12 volts going to it??? this relay box is pretty common to go bad--u have to remove the air cleaner in order to get to it.get back to me.

check the true psi with the line psi to see if same if psi is good in cooling 225 hi and 70 low on 80'day then compressor is fine and i would start checking for temp difference on the reversing valve sometimes this will cause high suction or high discharge psi shift it manually with by energising it be cooling or heating then pull wire and see how it shifts if shifts good then txv on out door unit could be bad what is the psi in heating on the discharge line going to the indoor unit? most prv's are set at about 350 psi r22 as for suction line size its only hot gas in hp mode os no problem their shows in cooling mode as low suction psi ..hope this helps some also make sure indoor coil is clean!....thanks & rate me

The Freon goes into the "suction" hose/pipe assembly. There will be a service port on this hose. The low side (blue) hose of the manifold gauge set gets connected to this fitting. The suction hose can be identified by it's larger diameter (compared to the discharge and liquid hoses). The suction hose will run from the compressor across the top of the radiator (slightly behind the radiator), then back towards the firewall on the passenger's side of the engine compartment. The service port is generally closer to the firewall, than to the compressor.