cool air on driver side, warm to cool on passenger side

[Tuesdak]

What i do know is that towards the rear of the compressor there is a bunch of dye visible when using a UV light. Blasting it with brake cleaner didnt dissolve it so im thinking it could be pretty old. Or I had one of those events that @petersonj mentioned in the first reply. Directly on the back of the compressor there is a bit of what looks like old oil. would have to scrub it off as its dry.

Using the UV light I see no signs of dye at the exit of the evaporator, around the accumulator or any of the fittings towards the back of the engine. Only near the compressor is where I can see dye.

So I obviously have a leak somewhere as the shop filled the system 1 month ago.

Quick and dirty test to see if you have a blend door problem or low on charge: feel the inlet and out pipes of the evaporator at the fire wall. They should both be cold and nearly the same temp of cold. If the outlet pipe (going to the accumulator) is warm your system is likely low on charge.

Old dye is easy to figure out. Look for dye on the Oil Filter as it gets painted with oil and dye from the relief valve opening at 450+ psig. Assuming you have changed the oil since the A/C work.

For 2003 and IMO other years: there isn't anything acted on in the ECM to kick out the compressor when the high side hits or goes over 450+ psig. Failed cooling fan, clogged radiator, slow to kick on cooling fan clutch, whatever. The A/C system overheats to the point the relief valve blows 1/2 the system charge out at the safety relief valve. These pickups did this even brand new so they don't need a reason you can fix to dump 1/2 the A/C charge out the safety high pressure relief valve. 500 psig and the word "Safety" don't really go together as nothing is safe at 450+ psig except it keeps the high side of the A/C system from exploding.

In depth.
https://www.turbodieselregister.com...rams-ecm-defect-opening-the-ac-relief.258779/

Although the advice is to treat this like other systems the only way to know the proper charge is to evac and recharge the system. These systems are a flooded evaporator meaning the charge is determined by filling up the evaporator with liquid R134A and adding ~1/4 to 1/2 LB extra liquid R134A into the accumulator. Gauges will not tell you how much is in the accumulator. Some of the extra is a leakage reserve. When the system gets low the accumulator no longer has liquid R134A in it. As the system gets lower the evaporator is no longer full of liquid 134A and the outlet piper becomes warmer than the cold inlet pipe. These systems actually blow colder when they are slightly low and just about to starve the compressor for oil. Our compressors are tough and live through this oil starvation better than some others that would quickly fail. Refrigerant carries oil and low refrigerant conditions leave the oil trapped in the evaporator.

The orifice tube frosts when the pressures are low and defrosts when the fan kicks on.
this cycle repeats twice in a 5 minute span.

Either the orifice tube is clogged with debris, again, or the system is extremely low. These systems can frost the entire line from the orifice tube to the evap and the evap to the accumulator... and the line clear down to the compressor under the right conditions.

Is the frost just at the orifice tube or does it go further all the way to the evaporator inlet? Is the blower on high?

Low side goes from 10 to 30 then drops when the fan kicks on.

Is this psig or F? Doesn't matter as it's below freezing either way. This reading alone is clear you have a problem. IMO low. Clogged orifice tube is possible...

What did they also replace when they said your orifice tube was clogged? Condenser (essentially the first big debris filter and debris collector in the refrigerant flow out of the compressor), compressor, accumulator and flush the system? Debris in the system comes from one of three things: Compressor failure, dryer material coming apart in the accumulator, or internal corrosion from a system running with a leak on the low side that sucks moisture into the system. PAG oil + moisture = corrosive acid.

Did you see the OT and verify it was in fact clogged? I would be asking what from and was it (symptom) source of debris cured. IMO it could look like a clogged orifice tube to a shop if the cooling fan isn't running as described as the defect these trucks have. Fan checks out and shop is scratching their heads wondering why the high side went high and blew the relief when charge is good and fan checks out.

 

[tjm]

Thanks @Tuesdak. Ive' read the threads, very interesting - like going dow the proverbial rabbit hole. Will have to re-read as there is a lot to digest.

My accumulator ports in and out are at different temps - so thanks for that pointer and the pointer on old dye vs new. Yea this is old dye.

Next step is to evacuate and see how much refrigerant is really in there, leak test and then determine next steps. I did order a new accumulator because they're cheap, easy to replace and genos offers a kit with an oriface tube and new seals.

 

[Tuesdak]

My accumulator ports in and out are at different temps

No. Evaporator in and out is what tells you something.

Accumulator doesn't tell you anything as it has some liquid going in from the evaporator and mostly gas coming out aside of what's needed to move the oil in the system via a small hole in a internal pickup tube. It accumulates liquid refrigerant so the compressor doesn't slug itself to death on liquid.

I would make sure the charge is correct before throwing parts at it.

Then inspect the old parts for internal debris. If you find any it's parts shotgun time. Condenser that can't be flushed effectively of debris, compressor, orifice tube, accumulator, and flush the rest of the system. I always replace the high and low side service valves on automotive A/C systems as they love to leak from internal system debris, running hot, etc.

 

[tjm]

No. Evaporator in and out is what tells you something.

Accumulator doesn't tell you anything as it has some liquid going in from the evaporator and mostly gas coming out aside of what's needed to move the oil in the system via a small hole in a internal pickup tube. It accumulates liquid refrigerant so the compressor doesn't slug itself to death on liquid.

I would make sure the charge is correct before throwing parts at it.

Then inspect the old parts for internal debris. If you find any it's parts shotgun time. Condenser that can't be flushed effectively of debris, compressor, orifice tube, accumulator, and flush the rest of the system. I always replace the high and low side service valves on automotive A/C systems as they love to leak from internal system debris, running hot, etc.

Evaporator is what I meant - My bad. Just got home and double checked, input cold output ambient (88F)

I'm gonna try and evacuate and pull a vacuum before I leave for Europe on Saturday. All my Amazon stuff should be here by then. If I have no leak and less than 1 lb 14 oz of refrigerant then I'll fill er up.

I'll update as I know more

 

[tjm]

I'm going to try to evacuate my system tomorrow afternoon. Assuming I have no leaks I'll be adding the required amount of PAG oil through the high side port (remove schrader) and vacuum it in. Question : If i put the system under vacuum again to remove the air and moisture for 30 - 45 minutes will that remove the oil i just added?

I have a robinair vacuum pump 3 CFM so not a lot of sucking power.

 

[Ozymandias]

The oil stays in no matter what you do, it can only be taken out by disassembling the systems parts.
So - no you don't add any oil to a system that is already charged.

Evacuation takes a lot of time, and take the time. I had mine run for at least 45 minutes till the vacuum really stabilized. And I haven't had a great pump to, only reached 1800 Micron which is high, but does the job, lower would be better.

 

[BigPapa]

The oil stays in no matter what you do, it can only be taken out by disassembling the systems parts.

Our recovery/charge machines at the shop can/will/do pull oil out. It goes in a clear jar so you can see how much came out and replace it.

 

[petersonj]

My Snap-On recovery / charge station behaves the same way.

- John

 

[Ozymandias]

That's with a Machine that takes out the fill fast, the oil foams up during the process and is pulled out together with the R134A.
He vents it manually so the oil stays (hopefully) in as he can't measure the exact amount that is lost and it is very important to have the exact amount in the system.

 

[tjm]

ok evacuated and placed under a vacuum late this morning. had 16 oz in. so in 5 days i lost almost 1/2 the refrigerant. I could only vacuum down the system to 27.5 in of Hg over a 1 hr period. In 30 minutes I lost 2-4 inches of mercury.

I recharged the system (new refrigerant) to see what performance i would get with 30 oz. Both the evaporator in and out ports were cold and sweating, 88 F outside at 11am. I didn't measure any driver / passenger vent temps. So maybe a symptom of low charger is the input to the evaporator frosts up? Or maybe the shop didn't purge lines correctly?

I also experienced some rather High AC high side pressure as @Tuesdak outlined in that massive thread on engine start up.

AC off, start engine, turn AC on.. high side pressure climbed to 450 while fan RPMs hovered around 450. I turned the AC off and started driving. When I noticed the Fan RPMs jump to 1000+ I turned the AC back on. Pressure seemed normal 200 ish. 95 degrees out now.

I checked for new dye and there doesn't seem to be any splattered round the engine bay. And there is no die on the oil filter either. so all the dye I'm seeing is when I overcharged the system and the relief blew (ten years ago). The dealer fixed it without cleaning the engine. Anyone know how to remove backed in die? I'm thinking a fine grit sand paper, a littler courser than a scotch pad.

I also examined the system while running for any die leaks - New dye would be bright yellow and the baked on die dye has a burnished, dull cast to it. I didn't see any.

My next steps are R143A leak detector. At the rate I'm losing R134A it has to be a fairly big leak.

Any other things I should be looking at?

Any and all help very much appreciated.

Tim

 

[brucejohnson]

ok evacuated and placed under a vacuum late this morning. had 16 oz in. so in 5 days i lost almost 1/2 the refrigerant. I could only vacuum down the system to 27.5 in of Hg over a 1 hr period. In 30 minutes I lost 2-4 inches of mercury.

I recharged the system (new refrigerant) to see what performance i would get with 30 oz. Both the evaporator in and out ports were cold and sweating, 88 F outside at 11am. I didn't measure any driver / passenger vent temps. So maybe a symptom of low charger is the input to the evaporator frosts up? Or maybe the shop didn't purge lines correctly?

I also experienced some rather High AC high side pressure as @Tuesdak outlined in that massive thread on engine start up.

AC off, start engine, turn AC on.. high side pressure climbed to 450 while fan RPMs hovered around 450. I turned the AC off and started driving. When I noticed the Fan RPMs jump to 1000+ I turned the AC back on. Pressure seemed normal 200 ish. 95 degrees out now.

I checked for new dye and there doesn't seem to be any splattered round the engine bay. And there is no die on the oil filter either. so all the dye I'm seeing is when I overcharged the system and the relief blew (ten years ago). The dealer fixed it without cleaning the engine. Anyone know how to remove backed in die? I'm thinking a fine grit sand paper, a littler courser than a scotch pad.

I also examined the system while running for any die leaks - New dye would be bright yellow and the baked on die dye has a burnished, dull cast to it. I didn't see any.

My next steps are R143A leak detector. At the rate I'm losing R134A it has to be a fairly big leak.

Any other things I should be looking at?

Any and all help very much appreciated.

Tim

I had a similar loss of refrigerant in my '02 2500 a several years back. For about three consecutive years I would have to get the A/C system charged due to a slow leak. Seems like when we would go on vacation the A/C would feel OK at home in the cool Pacific Northwest. When we got into hot desert weather (>100*) the A/C would not cool very well...OK, miserable...about >85* in cab @ +117* outside. Eventually get back home and get it recharged. Would last a couple months over the winter. Then off to vacation in more hot climates and the suffering continued. A number of key parts were changed over the three-year period. (most covered under the dealer's service warranty, or customer satisfaction repair for repeat issues) Each time there was no dye leakage detected. After so many returns, I got with the tech AND my favorite diesel mechanic (best expert and go to man in all things automotive and diesel) at the dealership for some serious discussion. Barring a couple obviously non-leaking lines and small pieces in the A/C system not changed in all that time, there was only one part that was not changed at least once, the A/C compressor. My good buddy, the diesel mechanic, said (and provided a learning experience for the A/C tech) the compressor would be the most likely item causing the issue as the routing design of the internal works could very well mask the escaping dye under certain conditions. One compressor later, the A/C worked great for the last four years I owned that wonderful truck.

 

[tjm]

I had a similar loss of refrigerant in my '02 2500 a several years back. For about three consecutive years I would have to get the A/C system charged due to a slow leak. Seems like when we would go on vacation the A/C would feel OK at home in the cool Pacific Northwest. When we got into hot desert weather (>100*) the A/C would not cool very well...OK, miserable...about >85* in cab @ +117* outside. Eventually get back home and get it recharged. Would last a couple months over the winter. Then off to vacation in more hot climates and the suffering continued. A number of key parts were changed over the three-year period. (most covered under the dealer's service warranty, or customer satisfaction repair for repeat issues) Each time there was no dye leakage detected. After so many returns, I got with the tech AND my favorite diesel mechanic (best expert and go to man in all things automotive and diesel) at the dealership for some serious discussion. Barring a couple obviously non-leaking lines and small pieces in the A/C system not changed in all that time, there was only one part that was not changed at least once, the A/C compressor. My good buddy, the diesel mechanic, said (and provided a learning experience for the A/C tech) the compressor would be the most likely item causing the issue as the routing design of the internal works could very well mask the escaping dye under certain conditions. One compressor later, the A/C worked great for the last four years I owned that wonderful truck.

That's a good bit of insight there Bruce.

I have a new evaporator for the blend door install - no dye at the water outlight. I bought a new accumulator. I have a new oriface tube I think Im just going to buy a new condenser, compressor, and schrader valves as I'll have a week in july to Diagnose, order parts, and repair.

does anyone have any suggestions on either of those 2 units. Condenser will have to be aftermarket.

 

[BigPapa]

The orifice tube is made into the liquid line.

 

[tjm]

The orifice tube is made into the liquid line.

Yep. - Shop installed a new line

 

[tjm]

Here is a pic of the high pressure situation right after startup and after the fan RPMs kick in to 1k+

 

[tjm]

Here's AC pressure high while I'm driving.

 

[petersonj]

One compressor later, the A/C worked great for the last four years I owned that wonderful truck.

Bruce, I had a similar experience losing refrigerant each year for two or three years. I decided to just replace the compressor as opposed to any other component. I based my decision on the likelihood of a dynamic seal leaking (compressor shaft seal) would greater than a static seal or another component leaking. Turned out to be a good decision as the AC is working fine now 100,000 miles later.

- John

 

[BigPapa]

Good deal. I was just going off your post.

I have a new oriface tube…

 

[Ozymandias]

With the sniffer you should find the leak rather quick. They are very sensitive.
First place to sniff is the center dashboard louver with the fan on.
If there is nothing you can relax as you don't have to pull the dash.

 

[tjm]

With the sniffer you should find the leak rather quick. They are very sensitive.
First place to sniff is the center dashboard louver with the fan on.
If there is nothing you can relax as you don't have to pull the dash.

dash passed the sniff test.

Thanks for that Pointer @Ozymandias