AC Performance

[andcunning]

I’ve read a lot of threads about AC performance on here, but I can’t tell if my car is performing as expected or not. A lot of people complain about a weak AC system, but another lot say they get 40 out of the center vent.

I have replaced my radiator and heater hoses, fan clutch, heater control valve, compressor, condenser, air drier, expansion valve and at 102 outside I’m still only getting 65 at idle and 55 while out of the center vent. It’s like 80 in the car after an hour.

It doesn’t start to cool off in the car for 10 minutes or so at 102, and I’m still sweaty. After an hour at highway speeds it’s tolerable.

When it’s in the 80s and 90s outside it feels cool quickly.

Is this expected or is there something else for me to look at? The shop charged the system by weight and the nature I have no leaks.

 

[77mustard40]

Personally experience on an original AC system (approximately 284 on the clock), cold AC within a couple of minutes, as of Friday in TX nearly 100. Yes it takes some time for the AC to cool the cabin, even on the highest recycled air setting, but I know it’s working at capacity in minutes at the most. Never have measured the AC temp of the air but I rarely max the temp setting on the dash which dictates the compressor engagement. My $.02 from experience.

 

[Fj80oregon]

With those hot temps and your truck idling with no air moving over the condenser then your temps sound about right. Now if you’re driving with air flowing over the condenser your temps should be in the 40s-50s. Try putting a fan in front of your truck on high at idle and see if it works better. Many upgrade to a fan for these conditions, that’s what I did. I installed a pusher pan in front of the condenser and I get 40-50 degree temps in any condition.

 

[TheBussman]

Are you 100% sure your engine is not overheating? when it overheats it will turn off the AC. i don't know what year your truck is but if you have obd2 its pretty easy to plug in and see the engine coolant temp. im in the 40s when its 80 outside with the smaller pa15 r12 compressor.

 

[alia176]

Our A/C system is old and not the greatest for the current times.

Test #1: when your vent temps are abysmal, spray garden hose water on the front condenser and see if the vent temps drop by a significant amount. You'll need to purchase a cheap vent temp if you don't own one already!

Your coolant system has little effect on the a/c system but it still needs to be up to snuff in the TX heat during summer. This includes the fan clutch lockup condition. After all that, if your vent temps are still crap, but the garden hose makes it to go down to a decent amount, then I'd use a manifold pressure gauges to check the condition of your a/c compressor and orifice valve as well as the amount of R134a in your system. The high/discharge pipe out of the air comp should be too hot to the touch, and the low/suction side should be cold.

From the sounds of it, you threw a lot of parts at this issue, but if all those check out ok, then you can blame the a/c condenser that isn't able to shed the cabin heat fast enough. It's not the fault of the a/c condenser, but the lack of air flow getting "pushed" through it. The only time this happens is when you're on the hwy and the ram air affect takes place. In town traffic is a murder on our a/c system, especially during 100+ days.

I installed two 12" pushers in front of the condenser and life is now MOBETTA. This is a last resort thing, not a first thing to try. I used to have a Toyota pusher fan on the pass side of the condenser for years, but now have two 12" pushers for better performance while sitting in traffic. That is a Ron Davis radiator and it constantly pegs out at 205-212deg during hard climbs with the a/c on the hwy.

 

[Marco Lau]

I installed two 12" pushers in front of the condenser and life is now MOBETTA. This is a last resort thing, not a first thing to try. I used to have a Toyota pusher fan on the pass side of the condenser for years, but now have two 12" pushers for better performance while sitting in traffic. That is a Ron Davis radiator and it constantly pegs out at 205-212deg during hard climbs with the a/c on the hwy.

View attachment 4198162This^
I have this exact setup for many many years, Ron Davis, 2 - 11" Spal pusher fans in front of the condensor, Fan clutch with 20k oil, a vented hood.
A even better setup for colder AC is to ditch the mechanical fan and go with elec. fans. I have had this setup for over a year now with cooler engine temp. and more efficient AC. Not to mention i no longer worry about busted radiator due to fan eaten up the fins., but that is for another discussion all together.

 

[alia176]

View attachment 4198162This^
I have this exact setup for many many years, Ron Davis, 2 - 11" Spal pusher fans in front of the condensor, Fan clutch with 20k oil, a vented hood.
A even better setup for colder AC is to ditch the mechanical fan and go with elec. fans. I have had this setup for over a year now with cooler engine temp. and more efficient AC. Not to mention i no longer worry about busted radiator due to fan eaten up the fins., but that is for another discussion all together.

this is a great feedback, thanks for that. 20K is a thick fluid, holy moly!! Apparently we both have extremely chilled ballz now

 

[Marco Lau]

this is a great feedback, thanks for that. 20K is a thick fluid, holy moly!!

Yeah, 20k might be overkilled...when i had 20k in the fan clutch, my coolant temp pulling long grade in 2nd gear @ 4k rpm for a long duration of time, I have only seen my coolant temp get up to around mid 190s.....I also noticed these fan moves alot of air, and at certain point, the plastic tips of the fan blade will begin to deform or crack...The elec. fans are nice as they are independent of the engine speed and not connected to the engine block so to speak....Both systems have pros and cons, and can't really go wrong with your setup as it is proven...

 

[alia176]

Yeah, 20k might be overkilled...when i had 20k in the fan clutch, my coolant temp pulling long grade in 2nd gear @ 4k rpm for a long duration of time, I have only seen my coolant temp get up to around mid 190s.....I also noticed these fan moves alot of air, and at certain point, the plastic tips of the fan blade will begin to deform or crack...The elec. fans are nice as they are independent of the engine speed and not connected to the engine block so to speak....Both systems have pros and cons, and can't really go wrong with your setup as it is proven...

I totally understand where you're coming from with the electric puller fans. That RD radiator is an investment and having to go through two of them is plain redonk. However, your 3FE was and perhaps still is being pushed really hard for hwy grade climbing so I can understand why the tips were contacting the radiator. I don't pull above 3k for very long, and the turbo has added sufficient amount of torque which enables me to stay under 3k bulk of the time.