Suburban Owners AC Question - Does Your Truck Get Cold When It's Really Hot Out?

[my name is alex]

I'm contemplating going back to the mechanic that replaced my compressor, but I'm just not sure if I'm expecting too much from this AC.

My dual AC seems to cool the truck off fine when the overhead console tells me it's ~95 or under, but when it's reading hotter than that the truck just never seems to get real cold. It's definitely cooler than if the AC wasn't running, but is still often somewhat uncomfortably warm.

My old 2001 Expedition would quickly get meat locker cold regardless of how hot it was outside, but is the Suburban just not capable of this (larger interior and perhaps inferior cooling system?)

I'd love to hear what other Suburban owners feel about their AC on real hot days.

 

[BowtieBrody]

I really don't even bother with AC, I just drive with windows rolled down.

But I do notice a slow cool time, and my 97 has all new AC components.

 

[slowburb]

The issue is *probably* that the mechanical clutch fan doesn't pull enough air over/through the condenser, which is with the radiator behind your grill. Your evaporator and or conderser may be clogged with dirt/trash/debris also. Some guys replace the mechanical fan with other GM mechanical fan/clutch setups. IIRC, a trailblazer fan is a good swap. The fan is plastic, there are more blades, and they have a different pitch than the fan on your rig. Also, it fits in the shroud with only a little trimming around the opening of the shroud. This means the fan is capable of pulling a lot more air across the condenser. I think I've read that a duramax fan also fits here. The other options is to retrofit an electric fan setup in place of the mechanical fan. There are literally hundreds of threads on this, anywhere from using 4.8/5.3 GM pickup dual fan setups to aftermarket setups from BeCool or Spal, or others. The most popular electric fan setup is a single fan from a Lincoln Mark VIII (or a mid '90's Taurus), because it fits in the factory shroud, and pulls many times the CFM that the clutch fan does. Guys that have done this swap claim you can stand at the front of the truck and feel the air being pulled into the grill opening. Most electric fan setups draw quite a bit of juice and have somewhat complicated wiring setups with relays and switches to get them to work to cool the engine and activate the other fan or higher speed to work with the AC. The elecrtical draw might require a more powerful alternator to not strain your existing charging system.

My Suburban doesn't do so well cooling on hot summer days in stop/go traffic, and my opinion is that it is because of what I've mentioned above. It definitely cools better while ripping down the interstate, and it definitely cools better at night than it does during the day. I cleaned out the condenser and it got a little better. I tried to get my hands on the parts to run the Lincoln Mark VIII fan, but there are literally none left unless you hit the junkyards. This was such a popular swap among hotrodders a few years ago that the fans are now extinct from Ford/Lincoln.

 

[df2x4]

Mine's been like that for a while, it's in the shop right now getting a leak in the system fixed. Finally went out a couple weeks ago. I'll let you know when I pick it up how much of a difference it made, think it's had a slow leak for years.

 

[mistaake]

Mine has never worked since I got my Suburban. When I get the money together to get it diagnosed I will try to remember to update this thread, but unless you whack me in the face with it I probably won't remember lol.

 

[99'Subourbon]

I don't have A/C atm, but when I did have it, it was mediocre at best. Mostly useless in Phoenix Arizona.

I plan on putting in an upgraded system sometime next year.

 

[my name is alex]

Thanks for all the replies guys. I guess I am just expecting too much out of the ac.

slowburb - that's an interesting idea. I have noticed the ac seems to work a bit better on the freeway.

Subourbon - how are you planning on upgrading the system?

 

[Dr.Zoom]

Subourbon - how are you planning on upgrading the system?

Wondering the same.

 

[df2x4]

Thanks for all the replies guys. I guess I am just expecting too much out of the ac.

I really don't remember mine being that bad when everything was fully operational. Like I said, I had a couple system recharges and hot summers before I found out I was leaking from the rear lines. From what I remember mine gets pretty damn cold, it just takes it a little while. Like I said though, I'll let you know how it works when I get it out of the shop next week. Should be early, Tuesday or Wednesday at the latest.

 

[slowburb]

Thanks for all the replies guys. I guess I am just expecting too much out of the ac.

slowburb - that's an interesting idea. I have noticed the ac seems to work a bit better on the freeway.

Subourbon - how are you planning on upgrading the system?

Then it is as I stated. Your AC system is working per its design and intent. The trailblazer fan is probably a good, easy, straightforward upgrade. I believe it fits on the clutch in your truck, and i think they make less 'fan roar' than the stock fan. If you want a more involved upgrade, go for an electric fan setup. Make sure your alternator is up for it and upgrade if necessary with the right one. You have to spend a lot on a turn key setup, or do a lot of research to piece one together. Dual fans will require a new shroud and wiring. Single fan will require trimming factory shroud and wiring. If you Google search for this you will see tons of write ups and tons of threads with pics and wiring diagrams. One really thorough write up has been posted on quite a few of the GM truck message boards, uses the mark VIII fans, and uses OEM relays and connectors from other models. I thought that was clever because oem parts usually have more longevity and durability than aftermarket stuff.

I think gmt4xx trucks were some of the last vehicles equipped with belt driven mechanical fans. AC systems seem cooler at idle in vehicles with electric fans because they move more air across the condenser.

I thought I read once that a version of the gmt4xx SUV's had a helper fan. I can't confirm this because I've never seen one, but want to say it was a pusher fan. Maybe someone else can confirm or correct me on this.