88-94 5.7 Suburban A/C Diagnosis and Tuning

[cjcb1100]

Hate to keep bothering your thread but is the oem condenser sealed to the rad support with any kind of ducting or foam i have a large gab that air is getting around the condenser i guess i didn't notice before ??


Gona be tough finding that foam piece probably will have to make one

 

[L31MaxExpress]

Hate to keep bothering your thread but is the oem condenser sealed to the rad support with any kind of ducting or foam i have a large gab that air is getting around the condenser i guess i didn't notice before ??


Gona be tough finding that foam piece probably will have to make one

GM did not seal them with anything, hence no OE parts available. Anything one does will be custom.

 

[Schurkey]

...and easily accomplished with closed-cell self-adhesive foam weatherstripping. Available at any decent hardware/home-improvement store.

 

[L31MaxExpress]

...and easily accomplished with closed-cell self-adhesive foam weatherstripping. Available at any decent hardware/home-improvement store.

Air guides are a bit more of a challenge, but those are accomplished with thin sheet aluminum and a way to bend said aluminum.

I used two of these to seal the gap between the grille opening and the condenser, forcing air through the cooling stack instead of allowing it to travel around the stack by flowing toward and through the headlight openings.

https://www.lowes.com/pd/Hillman-6-in-x-18-in-Aluminum-Solid/3057643

 

[L31MaxExpress]

I noticed these on a newer van, then started noticing them on many vehicles. My 2011 Pathfinder has them and my mom's 2019 Titan.

On the later Express the OE air guides are 15801541 and 15801542 to get an idea of what GM is doing. It is easier to see the purpose with the grille shell removed. They force airflow coming through the grille, through the cooling stack.

You must be registered for see images attach

 

[cjcb1100]

well i installed the red tube not much of a change it was 74 outside and high humidity 60% . getting 34 - 175 ish witch is better but i put 60oz in the system seems like alot, lowest temp while driving was 42. witch sounds great but at 75 degrees i have been getting 40s its when it gets hot outside it struggles . guess we will see in a few days i added a secound electric pusher fan and i moved the orifice tube into the condenser. all id like to get is 45 ish at idle when its 100 out but i dont see it happening

 

[L31MaxExpress]

well i installed the red tube not much of a change it was 74 outside and high humidity 60% . getting 34 - 175 ish witch is better but i put 60oz in the system seems like alot, lowest temp while driving was 42. witch sounds great but at 75 degrees i have been getting 40s its when it gets hot outside it struggles . guess we will see in a few days i added a secound electric pusher fan and i moved the orifice tube into the condenser. all id like to get is 45 ish at idle when its 100 out but i dont see it happening

Humidity has more effect than temperature on ac vent temps, meaning the ac will stuggle to cool more with high humidity than it will with high heat.

 

[cjcb1100]

does 60 oz seem like way to much? i doubt my capacity increased that much

 

[Wildblue19]

Once you start changing the factory system, IE different orifice tube and a change in volume with a parallel flow condenser, factory specs become only a suggestion. I would think the refrigerant volume would be lower than 60oz, but you will have to read back through this thread to see recommended superheat values and operating pressures.

 

[L31MaxExpress]

well i installed the red tube not much of a change it was 74 outside and high humidity 60% . getting 34 - 175 ish witch is better but i put 60oz in the system seems like alot, lowest temp while driving was 42. witch sounds great but at 75 degrees i have been getting 40s its when it gets hot outside it struggles . guess we will see in a few days i added a secound electric pusher fan and i moved the orifice tube into the condenser. all id like to get is 45 ish at idle when its 100 out but i dont see it happening

Where did you pull the 60oz figure from? I really only charge 100% stock systems with specific charge amounts. Everything else I do by pressure, temperature and feel. By monitoring the evaporator inlet and accumulator outlet, when you hit the correct charge, it becomes very obvious. The lines get very close to the same temperature and the pressures drop on both sides of the system.