my ac isnt cooling that great, so i thought i'd check the ac pressure.
i found the high pressure port, but cant find the low pressure port. anyone know where it is?

They are both on the same tube. Low pressure is to the back closer to the firewall and the high pressure is closer to the front of the truck.

Here is the parts diagram
The low side service charge fitting is on the accumlator(round can)number 23
The low side service charge fitting cap is number 15
If you are using a manifold set the high side service fitting is number 30
Do not charge on the high side of the system,Low side only.

http://www.compnine.com/largeimg/070112TG09-706.gif

With rear A/C the service charge fitting location is the same.

http://www.compnine.com/largeimg/050617TG09-717.gif

CC

119045

black cap in the back is low
greyer colored cap in the front is high. Different sizes so if you go to add, the fitting from the can is only going to fit on the right one anyway

And yes, I just ran out and took the picture of my 06 a/c lines.

Here is the parts diagram
The low side service charge fitting is on the accumlator(round can)number 23
The low side service charge fitting cap is number 15
If you are using a manifold set the high side service fitting is number 30
Do not charge on the high side of the system,Low side only.

http://www.compnine.com/largeimg/070112TG09-706.gif


CC

ok, i'll have to look again. i think there was a wiring harness blocking my view of the top of the accumulator.

And yes, I just ran out and took the picture of my 06 a/c lines.
i appreciate the help, but this is the van subforum......and i have a van.;) and the ac setup is different.

ok, i'll have to look again. i think there was a wiring harness blocking my view of the top of the accumulator.


i appreciate the help, but this is the van subforum......and i have a van.;) and the ac setup is different.

I know that I looked at your sig. before I posted it is from the catalog


2006 G2,3 Express 3500 Cargo/Passenger A/C Refrigeration system (LLY/6.6)

CC

I didnt even notice it was the van forum, I saw the question from the side and clicked on it.
At any rate, hope you get it worked out.

Glossed over that whole chevy express thing in your sig, just saw 06 and 3500

well, thats weird, my ac was working pretty nice today. although it was a little cooler outside...80 today vs 85 yesterday.
the low pressure valve is indeed on the accumulator, but what a b*tch of a location. i tried to connect my gauge to it, but it was tough, and everything around was hot, plus the foam on the accumulator may need to be trimmed to get the gauge on properly. i gave up and let it be, since the ac seemed ok today. if it acts up again, then i may have to take out the battery to get better access to the valve.
thats the one thing i hate about these vans....is working under the hood. lol

Post what the temp is and the pressure reading on the gauge,Is the comp. clutch cycling a lot or is it running continuously.

CC

Post what the temp is and the pressure reading on the gauge,Is the comp. clutch cycling a lot or is it running continuously.

CC

i couldnt get the gauge hooked up. like i said in my previous post, its a tough spot. and since it was working ok now, i gave up.
the compressor runs normal....continously for the most part. no cycling on and off. i just dont understand why it wasnt cooling as good the other day.

If it acts like its not working well again when it gets hot, here are some basic numbers to check with the guages.

Low side...............Evaporator Temp...........High side.........Ambient temp
...PSI........................Fahrenheit.......... ........PSI................Fahrenheit
16 - 29 ...................33 - 50...................115 - 200...............70 - 80
19 - 39....................33 - 60...................140 - 235...............80 - 90
25 - 43....................40 - 65...................165 - 270...............90 - 100
37 - 51....................48 - 65...................210 - 310..............100 - 110

these are general numbers, you might vary slightly and still be in a good range. But you can see that as the tempurature outside increases, it is possible that the charge on your system is a bit low and not allowing the system to work properly when it is perfectly fine at lower tempuratures.

well i finally got around to this again. ac worked good until the weather got in the 90's. so i decided to put the gauge on. it read ok(i only have the low pressure gauge), but i added about a half can of r134a and now she cools better.