what is my cooling setup?

Lv1G6He3V2 · March 8, 2012

99 Sierra 1500 5.3L V8 NBS 4l60E G80

After much reading, I'm looking to replace the radiator (28" -> 34"), in preparation for an electric fan setup (and engine mods later on). Radiators for this truck have a variety of options/connectors, so I need to know my connections and choose the correct unit.

The truck has three coolers:

Largest, must be main radiator. 4 hoses (2 metal, 2 rubber) on passenger side and 1 overflow tube on driver's side. I'm guessing this unit cools both engine coolant and engine oil.
Medium size, maybe a transmission cooler. 2 hoses (metal) on passenger side.
Tiny size, 2 lines: 1 on each side. Is this for the a/c?

Basically I want to replace #1, just want confirmation on what is being run through it.

Also if #3 is for the a/c, would replacing it with a larger unit improve cooling capacity? The stock a/c is anemic.

txab · March 8, 2012

#1 is the radiator. Has a transmission cooler mounted in it. (the 2 metal lines on the passenger side)

Radiator will be located last in the airflow line, closest to the fan.

#3. AC condenser will have the same surface area as radiator basically. Will be located in front of the radiator. Visible in this pic below. Note: radiator is completely hidden by the condenser in this pic.You may be looking at a power steering cooler. (Located on right in pic below)

Transmission cooling is done by radiator first, then if equipped an auxiliary cooler. (Center, front in pic. this is an aftermarket unit. OEM is similar, but smaller)

Lv1G6He3V2 · March 8, 2012

Ah, I missed the power steering cooler. That long thing on the right? Let's call that #4.

With #3 I'm referring to the small, rectangular cooler located in front of the condenser. In your picture, its hoses have blue zip ties. Mine is smaller, like half the size.

nickvrebel · March 8, 2012

you don't need the larger radiator.

I have worked on MANY high performance trucks and we never had an issue using the standard radiator for engine cooling.

This includes a 2000 model Z71 truck that was a 1/2 ton with a 6.0L swapped in, aggressive cam, headers and all the other goodies to go along with it. This motor also had an under drive pulley, which slows down the water pump. We used "LS1 fans" which have less cooling capacity than the "2005+ truck fans".

This truck was daily driven on the street and ran a best of 12.8 seconds in the 1/4 mile. It was located in South Louisiana which has some pretty harsh temperatures at times. It also towed small to medium sized loads on a regular basis. If this truck got away with a standard radiator, there is no reason you would need to upgrade your's.

Lv1G6He3V2 · March 8, 2012

My thanks to both of you!

I was anticipating the direct-fit of 2005+ fans on a 34" radiator, if I could get a good price on both. From what I've seen, LS1/LT1 fan shrouds do not appear to match the radiator's core dimensions, and mounting them on my 28" radiator requires some fabrication. But they would be much cheaper...

EDITED: Anyone know how to clean the remains of a bee colony out of my condenser without removing it?

txab · March 8, 2012

Try soaking the condenser with simple green. You may need to do these a couple of times. Then flush with water. There are products used in the HVAC industry to clean condensers. It foams on contact and pushes through the passages. Sometimes Lowes will carry this stuff or you can purchase from HVAC supply outlet. One type will remove paint from whatever it touches, so don't get that type.

If your condenser is pretty restricted your AC performance will be affected as well a radiator performance.

txab · March 8, 2012

Ah, I missed the power steering cooler. That long thing on the right? Let's call that #4.

With #3 I'm referring to the small, rectangular cooler located in front of the condenser. In your picture, its hoses have blue zip ties. Mine is smaller, like half the size.

Sounds like you've got an auxiliary transmission cooler

Next time post some pics.