A/C Cooling Issue

[kozakvod]

Approaching that time of year again when the need for cooling is important. I have had an ongoing issue that I would love to finally fix.

2014 Pete 388; ISX15 2350; 580k miles

Problem on a hot day: Turn on AC. Runs fine. Then after a while it will start getting warm and the air flow decreases. Sometimes I can flip the switch to high fan speed and it will eventually cool back off (NEVER gets cold, just cooler) and it may or may not get warm again, more often than not it will because I will turn my fan speed back down. Or other times I will just turn it off completely, wait 5 mins or so, turn it back on and it blows cold again.

Thinking that the decrease air flow sounds like the Evap Coil is freezing and not allowing air to flow thru it fully. I check, is condensation draining out? I stop, open hood, line from compressor is ice cold with frost on the lines. Once I get stopped it will POUR condensation out the tube, icy lines melt, starts blowing ice cold air again. Get it start driving, we go thru process again. Over and over all day. If I'm idling it will blow air so cold you can't keep on its coldest setting. Start driving there it goes.

I have replaced Hi Press switch. Both sensors. expansion valve. accumulator/dryer. None of these fixed the problem.

Anyone else have any ideas?

[stevesparts]

too much r134 in it (overfilled) get some of it out of there, take it to someone and get the right amount in it and you should be good.

[kozakvod]

(04-16-2020 )stevesparts Wrote:  too much r134 in it (overfilled) get some of it out of there, take it to someone and get the right amount in it and you should be good.

Was in Phoenix last summer and ran it by a shop and yes at that time it was overfilled. They pulled out some of the refrigerant to get the amount set correctly. Headed out of town and started doing the same thing again, BUT I will have it checked again to be sure.

[david24]

I'm having a similar problem with my 2014 Prostar. If I put it on max it be cold for a while then the line will freeze up and it stops being cold but if I put it on normal it blows cold all day without any problems.

[kozakvod]

(04-16-2020 )david24 Wrote:  I'm having a similar problem with my 2014 Prostar. If I put it on max it be cold for a while then the line will freeze up and it stops being cold but if I put it on normal it blows cold all day without any problems.

Sounds just the opposite of mine. Will your blow cold when idling?

[Moose]

When is the last time you cleaned out the evap coils and cabin filter? It does sound like it's freezing. How are the pressures?

The design for that cab series is the shittiest I've ever seen. The blower is AFTER both the heater and evap core and the condensate drain is between the evap and heater cores. So, ANY blockages and/or restrictions even just a slightly dirty cabin filter or fan speed on high create enough of a vacuum to stop the flow of condensate from draining like it should. There is no thermal switch in that system, just a TXV.

[kozakvod]

(04-16-2020 )Moose Wrote:  When is the last time you cleaned out the evap coils and cabin filter? It does sound like it's freezing. How are the pressures?

The design for that cab series is the shittiest I've ever seen. The blower is AFTER both the heater and evap core and the condensate drain is between the evap and heater cores. So, ANY blockages and/or restrictions even just a slightly dirty cabin filter or fan speed on high create enough of a vacuum to stop the flow of condensate from draining like it should. There is no thermal switch in that system, just a TXV.

I clean that filter at least 2 times a year and it probably needs it again now, but I haven't ran the A/C yet, but I know it's going to do the same thing again.

I have never cleaned the Evap coils since I have owned the truck 180k miles worth, and yes that's probably next step. Frustrating as heck though. We have been dealing with this for 2 summers and I'd sure like to find a solution.

[david24]

(04-16-2020 )kozakvod Wrote:  

(04-16-2020 )david24 Wrote:  I'm having a similar problem with my 2014 Prostar. If I put it on max it be cold for a while then the line will freeze up and it stops being cold but if I put it on normal it blows cold all day without any problems.

Sounds just the opposite of mine. Will your blow cold when idling?

Yes, it still blows cold while idling

[Lonestar10]

probably need to make sure the hot water to the heater core is off. might help soon as i put a hose clamp vise grip on one of the hoses to heater core last year my life was never the same as far as how good the truck cooled down on a real humid day i could be throwing fog out the vents it was so cold.