Yesterday was the first real hot day (85+) since I've had my dmax. The AC was cool at best after running for over 1/2 hour in recirculate mode. I was thinking that I was low on r134 but once I got out of the traffic and started moving it got cooler.. Not icy cold but cooler. Sitting still at 2000 RPM the AC was still just cool so engine RPM has no effect. I suspect the condenser needs more airflow at idle to dissapate the heat.

Is this normal? Would a can of r134 help keep the AC cooler eventhough the problem appears to be airflow across the condenser?

Sitting in traffic on a hot day sucks when you don't have ICE COLD AC.

Thanks..

I believe there is a TSB on the AC. I took mine in and they removed some of the Freon and it worked better. You might check on this.

Thanks rmjdmax!!
I just checked the TSB section and guess what I found? (http://www.dieselplace.com/forum/showthread.php?t=220) :)

I was just going to post the same thing about the poor A/C. It's been terrible since I bought the truck, but GM has been issuing Technical Service BANDAIDS and I've been waiting for a final-final fix. This may be my last summer before the warranty runs out, so I'll probably have to get something done in the next couple months while it's hot. Today was the first day I drove in warm weather this year and I think I got hotter being PO'd at the bad A/C then by the outside heat. My '02 would freeze you out. I guess I'll rip out the Edge and call for an appointment.

Hmm

Mine works great! have to turn it down half the time,no kidding :)

Hmm

Mine works great! have to turn it down half the time,no kidding :)

That's because you have a 2001 truck. GM changed the system for 2003, most of the 2004s and maybe some of of the 2002s. The new accumulator covered in the TSB is a big improvement.

Mine is an 03 and never had no problems with a/c cooling. With rec. on I dont want the blower on above #2. 43* at idle and 38-39* going down the road.

Just a word about the TSB, Document ID# 1539443: The new accumulator and associated parts are for trucks equipped with Denso compressors. Mine has a Delphi compressor. They did do the "lower the charge" thing and it is better, but not like some I have had. At least in 2002, they were using these two compressors. Be sure you have a Denso compressor before going in for this. The dealer did order all the parts for this but wasn't upset at all after seeing I had a Delphi as they will surely use them on a truck with a Denso.

Steve

I've owned an '04 for about a month now, yesterday (6/6), it was over 90 degrees here and I had the A/C cranked and I was not impressed. So I thought that maybe once I got moving that it would help, and it did not!! So I assumed that there was a problem with the system. As I got checking, I found that my wife had previously turned the vents off on the passenger side, as soon as I opened them I could instantly feel the temp drop dramatically! Evidentally, it needed more air flow! So be sure that all your vents are open! But even after that, I ran it full blast all day, even on recirculate and it was just tolerable. My '95 GMC would cool easily on #1 fan setting. The crew cab and the fact that the truck is black probably doesn't help any either, but I'm not impressed at all. Plus this R134a has never been the A/C that R12 was.

R134a is a totally different animal than R12. More R134a is NOT better. A propoerly functioning R134a system should cool just as well as R12, but it takes a little bigger system to do it.

My AC is the worst. I've had it in when it was under warranty, no real change. Now its out of warranty, and this past weekend it was blowing warm air. What a joke. It is the #1 complaint I've had on this truck. And GM wants to give you some garbage about it's only supposed to blow a certain temp, and even if it's not cold it's still cooling.. ya whatever. Doublespeak for an absolute POS engineering mistake.
I'm done.

WOW.... another reason to keep my 02... cold A/C... First thing to check is to make sure A/C compressor is actually ON, the low press cycling switch can be bad, keeping compressor off. And also many other inputs to ECM, ie: P/S pressure, idle speed, coolant temp, if any are wrong,even if just a sensor, will keep compressor off

If you have a tune uploaded in the truck remove it and return to stock. I have had heater/ac malfunctions after loading a tune. Returned it back to stock and reloaded and all worked well afterwards. Just thinking.

My 03 has been horrible since the day I purchased it as well. I've had it to the dealer many times. Responses the first year were always along the line of, 'It's working as designed'. Finally I put food thermometers in each vent and then another one up near the roof console so show the 'cabin temperature' and took it to the dealer. Althought they claimed to have adjusted the coolant level previously, they did it again and that helped. It does blow cooler, but it's still not good.

This is my single biggest complaint with this truck. I live in Texas and when it's hot, it takes about 20 minutes at full blast for it to get down to blowing 62 degrees.

My 03 AC works good

It was about 90* yesterday and with just AC on the vent temp was 65*

But with Recirculate on the vent temp was 48*

That's because you have a 2001 truck. GM changed the system for 2003, most of the 2004s and maybe some of of the 2002s. The new accumulator covered in the TSB is a big improvement.

My 03 will freeze your a$$ off and that's what I like.:eek: I hope it lasts because its been too freakin' hot for my overly insulated posterior.):h

Finally got the dealer to perform the accumulator TSB on my truck last week (the first one that Classic Cheverolet has done they say). With temps ranging from 90 - 100 degrees in North Texas since the fix, I'm getting cooling temps down in the low 40's within the first 5-10 minutes and roughly 60 degree vent temps almost immediately.

Thanks to the information I found on this web site, and after 2 years / 60,000 miles of griping, my AC works the way it should! whew!

I brought mine to the dealer last Wednesday and they ordered all the parts in the TSB..

Cold A/C here I come.. :)

Just waiting for the parts to come in..

Does anyone know if this applies to 04 models? Mine is ok but its not great. It definitely won't keep up at idle. It just keeps up on the highway.

Mine seems to do pretty good, both idle and on the highway. Maybe I haven't sat long enough in traffic yet to see what others are. I keep it in recirculation all the time, but it's pushed 100 a few times this year, and last year over a few times.

Does anyone know if this applies to 04 models? Mine is ok but its not great. It definitely won't keep up at idle. It just keeps up on the highway.

Looks like it does.. http://www.dieselplace.com/forum/showthread.php?t=12476

Thanks.

Does anyone know if this applies to 04 models? Mine is ok but its not great. It definitely won't keep up at idle. It just keeps up on the highway.

Max,

The TSB applies to most, but not all of the 2004.5 models. GM made a production change to the accumulator during the model run, starting approx. June 1st, 2004. This means for the last month of the 2004.5 model run, the new accumulator was used.

Since you bought your LLY truck in July, 2004, you may have a June 2004 truck. Here are links to a couple of threads with photos of the accumulator:

http://dieselplace.com/forum/showthread.php?t=15670&highlight=accumulator

http://dieselplace.com/forum/showthread.php?t=22238&highlight=accumulator

Another thought is to stop by your local GM dealer and look at the accumulator of a 2005 model. If it is the same as yours, then you have the upgrade.

I am somewhat surprised that you are having a problem. I didn't think it got hot in your part of the world. There are some posts in this thread saying their 2003 or whatever is cooling great. That is because it does not become a big problem till the outside temp gets close to 100(F) degrees. Similar to the LLY overheating problem, everything seems ok to a certain point, then it fails dramatically. If they were at Phoenix Sky Harbor yesterday when it hit 114(F) degrees, they would have a different point of view! No matter where I live, I would try to get it fixed. You never know where you may be visiting or moving. Also, it is a good resale point.

From a post I made back in January when asked if I had the part numbers -

"Found it! Document ID# 1539443. Also refers to #02-01-38-007C (July 27, 2004). Back then anyway, 2002 to 2004 model year LB7, LLY. Four pages long. Applies to DENSO compressors. I have a DELPHI, so the other suggested fix is to lower the charge from 1.8 lbs to 1.6 lbs.

Steve

On edit: The parts required as stated on The Diesel Place before are:
Accumulator - 89018601
Hose Assembly - 15136596
Bracket - 15136597
Insulator - 10372792"

Note that the fix applies to DENSO compressors. They did lower the charge. Not much better.

Steve

Max,

The TSB applies to most, but not all of the 2004.5 models. GM made a production change to the accumulator during the model run, starting approx. June 1st, 2004. This means for the last month of the 2004.5 model run, the new accumulator was used.

Since you bought your LLY truck in July, 2004, you may have a June 2004 truck. Here are links to a couple of threads with photos of the accumulator:

http://dieselplace.com/forum/showthread.php?t=15670&highlight=accumulator

http://dieselplace.com/forum/showthread.php?t=22238&highlight=accumulator

Another thought is to stop by your local GM dealer and look at the accumulator of a 2005 model. If it is the same as yours, then you have the upgrade.

I am somewhat surprised that you are having a problem. I didn't think it got hot in your part of the world. There are some posts in this thread saying their 2003 or whatever is cooling great. That is because it does not become a big problem till the outside temp gets close to 100(F) degrees. Similar to the LLY overheating problem, everything seems ok to a certain point, then it fails dramatically. If they were at Phoenix Sky Harbor yesterday when it hit 114(F) degrees, they would have a different point of view! No matter where I live, I would try to get it fixed. You never know where you may be visiting or moving. Also, it is a good resale point.

Although we do get really cold weather we also get pretty warm weather in the summer. It was 93 degrees today and next Monday they are talking about it getting closer to 100. Last saturday was 96 I believe and very high humidity. We will never see much over 100 but it does happen.

My dealer has the parts on order and I will get the upgrade next week. I have the denso compressor. They said this will be the first they have done.

Max Power ..... Wow! 100 (F) degrees in the summer and as I recall you have said it gets to minus 20 or colder in the winter. That is quite a range.

You should definately notice an improvement after the upgrade. It will probably not be as good as the 2001 or 2002 trucks with the Delphi compressor, but it will be better than what you have now.

Let us know how it works out. You might want to get some vent temp readings before the upgrade so you have some benchmark numbers for a before and after comparision.

I took my 2003 in 2 years ago (1 month after purchase) for taking 15 mins to cool (Texas +98 temps). The work order showed a new orifice and lowering of freon charge. Has worked great since. About 5 mins to get cold when in traffic, less if on highway. The rear view mirror temp can say 98-105 and I usually have the a/c set for fan #1 and drivers side cold/heat set up two clicks. If I set the fan any higher or colder, I get a sore throat and freeze my wife out.

The new accumulator and associated parts are for trucks equipped with Denso compressors

I did mine, and it works. I have the Denso compressor. I replaced the accumulator and the hose ( you have to, the old one will not bolt up to the new accumulator). I can not believe the difference it made.

About 20 degrees at the center vent! From 60 to 40 on a 98+ day.

The fact that they made the new new accumulator not accept the old hose makes me think the problem may be with the hose it self. (the hose mounts in the same position they just moved the bolt for the hose 180 degerees to the opposite side so that it wouldn’t work.)

Currently in New Mexico as I travel this great country of ours.. 95 deg from Oklahoma City to Albequerqe *sp* , and I had to drive with the windows open, since my AC set at 60 kept the cabin temp at a comfortable 88 deg -:t .
Leather seats in an 85+ deg enviornment = massive crack sweat :help2:

To be continued...

For anyone who has had success do you know how much it was charged to? I want to make sure the do it right the first time.

I do a lot of a/c work on heavy duty trucks.More freon is not better.Overcharged system will not cool as good...just as undercharged won't cool as good.My 2004 works great..Stupid truck just keeps serving me well.I feel left out when it comes to problems....Now that I have opened up my big mouth it'll probably not start tomorrow morning.

For anyone who has had success do you know how much it was charged to? I want to make sure the do it right the first time.

My truck calls for 1.6lbs. One pound is 16oz half of that is 8oz. The R134 that I bought was in 12oz cans. I charged it with two full cans, thats 24oz = 1.5lbs and it works great.

Before I installed the accumulator I put about 3oz of RPAG oil in it.

NOTE: IF YOU DONT HAVE A VACUUM PUMP TO PULL A VACUUM, DONT EVEN TRY IT!!!!

My truck calls for 1.6lbs. One pound is 16oz half of that is 8oz. The R134 that I bought was in 12oz cans. I charged it with two full cans, thats 24oz = 1.5lbs and it works great.

Before I installed the accumulator I put about 3oz of RPAG oil in it.

NOTE: IF YOU DONT HAVE A VACUUM PUMP TO PULL A VACUUM, DONT EVEN TRY IT!!!!

The proper correct way is to pull a vacuum. This should pull the contaments out of the system. BTW, I used to work refrigeration.

However, if you don't have access to a vacuum pump, you can still make it work by flushing the system with freon (R134a only) or an inert gas. I have done this twice on family members vehicle in emergencies and have had no problems. Just make sure you change the accumulator, as this device filters out the contaments that you didn't remove. I am not saying for everyone to do this, but it is a "redneck" method that works in an emergency.
:grd:

On the dealer work order for my 2003, the tech stated that the system was overcharged by 1 lbs and was adjusted for "correct" charge.

So what's the right temperature drop across the evaporator sitting idle?

I got my truck back today after the accumulator and associated mounting hardware was replaced as per the TSB. The A/C is colder then I've noticed before, however, today was not a 90+ degree day. The next hot and humid day over 90 degrees I'll be able to tell if the TSB fixed my problem. I hope it did.

I had mine in for the memory seats not working right and the horn not working a week ago, had them do the TSB on the AC. I thought it was fine before, but now, WOW!!! It's cold very quick and at 100 degrees it takes much less fan to keep the truck comfortable. You will like the results I am sure!

Well......... It's official. The TSB fixed my problem.
Today - 95+ degrees - icy cold A/C.

:cool: :cool: :cool:

:cool2:

:help:
I had TSB 02-01-38-007C performed on my truck last August, it seamed to be working OK. I never really had in in any hot weather until last week. I helped my son move to Las Vegas, it was over 100 every day. The AC worked fair driving 50 mph or over, but in slow traffic it would just cool a little. My son's boss has a 2003 GMC, CC 3500 "Dooley", LB7/A, 4x4, with a service bed on it. He took me for a ride is his truck. It would freeze us out if left on 60 setting on the dual climate control. He said his was just like mine until he had it worked on at a GM Truck center in California. He did not know what they did to it, but he said the service man knew just what he was talking about when he told him the problem. Is there any TBS's after 02-01-38-007C? I have an appointment next Tuesday to have mine checked again. I would appreciate any help on this as my truck is just about out of factory warranty.
:help2: