03’ International 9900i A/C not cooling well

[Redland1]

Hello all. The A/C in my 03’ international 9900i hasn’t been cooling well lately.So far I emptied the system of refrigerant,vacuumed it down to 30Lbs for 20 minutes,and refilled with 4-12oz cans of R-134A.According to everything I pulled up online it’s 3lbs of refrigerant for my truck.Still not cooling well.

[Soulreaver0102]

I have an 07 9900ix. When I bought mine I thought the AC was a little on the warmer side. I have to hit the bunk button and then it blows cold. I’m unsure if that helps you any.

[Redland1]

(06-12-2022 )Soulreaver0102 Wrote:  I have an 07 9900ix. When I bought mine I thought the AC was a little on the warmer side. I have to hit the bunk button and then it blows cold. I’m unsure if that helps you any.

It usually run both at the same time.

[tree98]

Did you put gauges on it? Might be a weak compressor.

[Redland1]

(06-12-2022 )tree98 Wrote:  Did you put gauges on it? Might be a weak compressor.

I did but I went off of a video I saw on YouTube on how to refill it.What should I have been looking for?

[Mikanic]

I did but I went off of a video I saw on YouTube on how to refill it.What should I have been looking for?
[/quote]

When I fill a system and check the pressures of low side and high side here is what I look for:

-high side pressure should float from 200-350 psi, the fan should kick in at around 300-350 psi
-low side pressure should be 12-35 psi, the compressor should kick off around 12-15 psi

-These pressures are ball park but should be close to what you would see on any well functioning system. If you run with a 2 speed fan you should have pretty stable pressures on high side but I always like to see the compressor kick off after a couple minutes of idling. If you don't see the compressor kick off and you don't have good pressures, you either don't have the right amount of refrigerant or have a worn compressor I would say. If your compressor kicks off and you don't have the right pressure, you either don't have the right amount of refrigerant or may have a plugged expansion valve.

If your compressor does not kick off but the system is cold... send it down the road buddy its cold.

But most often than not when a customer comes to see me with a weak A/C system on a older truck like yours, assuming your heater box is original and you replaced your cab air filter, the issue is not the A/C system itself but its in the HVAC system. I'm a KW tech so I'm not familiar with those trucks but here is some things to verify before spending big money in the A/C system.

-malfunctioning blend doors (if applicable)
-malfunctioning water valves (if applicable)
-Plugged Evaporator cores with dust and dirt
-Plugged heater cores with dust and dirt

[Rawze]

A lot of the time on internationals, the system gets cold enough but you can't feel it for stick. This is because as they get older, the blend doors are notorious for not closing all the way, causing the system to blow barely cold or luke-warm air all the time. Shutting off the heater-core lines with shut-off valves helps a lot, and replacing the blend door motors, etc. as necessary to force all the air across the evaporator and away from the heater core is usually the main issues if the rest of the system is checking out ok.

[fast69mopar]

(06-12-2022 )Redland1 Wrote:  Hello all. The A/C in my 03’ international 9900i hasn’t been cooling well lately.So far I emptied the system of refrigerant,vacuumed it down to 30Lbs for 20 minutes,and refilled with 4-12oz cans of R-134A.According to everything I pulled up online it’s 3lbs of refrigerant for my truck.Still not cooling well.

I have two 9900i's. One is a 2005 model and the other one is a 2014. Both of them cool the same and the front A/C just does not cool as well as the bunk but like the others have posted you need to check a few things that are really easy to do.

Remove the passenger seat and the trim cover. Under the passenger seat is the HVAC housing. Remove the bolts around the perimeter and remove the top cover so you can gain access to the HVAC system.

Make sure you do not have any debris inside the HVAC housing that would restrict door movement. Check for leaves, old rags/towels etc. Operate the temperature control knob in the HVAC control head and watch the blend door actuator to see if it is moving the blend door properly from one side to the other.

Once you complete a visual inspection I would install the gauges again and monitor the high and low side pressures.

Like one poster states, blocking off the heater core lines to the heater core makes a huge difference in A/C outlet temps in the dash. I installed a pair of shut-off valves under the hood on the heater hoses. I used a ball valve and when I shut of the coolant flow to the heater core the A/C temps will drop another 10 degrees and really start cooling well.

[DVT873]

Also look at the condenser, usually mounted to the front of the radiator. Just make sure it is clean, and does not have a bunch of crap on it or in the fins.