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phill0072
07-18-2008, 09:19
I am looking for a good A/C shop in any of the following states I really need this thing looked at by a pro. I will do what ever it takes to get it working right. Following states I am in alot in no certain order OH,IN,KY,TN,IL,MI,PA,VA,NC,SC,GA,MD,DE,NJ,NY AND SOUTHERN WI. AND EASTERN IA. This is for work on a 06 express van with a lly system runs great while going down the road but when you first start it up and you have been idling for more than 5 mins its starts hissing and blowing warm air if I start to drive it, it will start blowing cold. Also i was sitting in a construction back-up yesterday and the a/c was great while moving but once I hit the back up it started blowing warm air and hissing only after sitting for 7-8 mins. of course the stealership said that the a/c on the diesel's don't work good at idle and so I wasted 98.50 and told him he was full of --well u know. I took the van to my personal mechanic and had the system evaced and had vaccum pulled for 20 mins and then was let sit for a hour and it did not loss any vaccum then they recharged it with the snap-on machine to the correct charge and it worked fine for a day but then on the next cold start up it started doing it again. My personal mechanic is good on alot of things but a/c is not his strong suit, so if there is any one out there that is top notch I will pay top dollar for your services. and if any one has any suggestions on what my be wrong with this please fire away. oh yea system had dye installed and I ran it for 80k and there is no leaks and they did replace the low side switch "the one on the accumalotr " and it still does it.

More Power
07-25-2008, 10:32
I know from experience that some systems will hold a vacuum but can slow-leak under pressure (which is how the system runs).

In the Tampa, Florida area, I'd recommend www.marksair.com (http://www.marksair.com)

Buy a kit from Wal-Mart for testing/recharging the R-134a systems. The instructions can help you understand the process and the gauges in the kit can help you troubleshoot a problem. The kit is pretty cheap.

Jim

phill0072
07-26-2008, 09:57
Thanks for the reply I have a set of snap-on gauges. I have noticed that on a 95 degree day with about 80% humidity the low side runs about 39 psi and the high side will go all the way up to 450psi. 450 seems to high for me but I could be wrong. I noticed that at idle on a cold engine with a/c on the high side builds quick, quicker than I have seen before on any other vehicle I have owned. I have also noticed if I spray the condenser with cold water the pressure will drop to about 220 in like 45 seconds and the a/c will start blowing cold again. The only thing I can thank to do is put a aux fan on the condenser with a switch so I can turn it on and off as needed, but I don't know if that will work. Can anyone tell me if 450 on the high side is okay, or is that the problem, possibly a restriction in the system somewhere? any suggestions would be helpful.

More Power
07-26-2008, 12:41
At 100 degree F ambient temps, the high-side pressure port should be in the range of 230-246 psi. Pressures get progressively lower at lower ambient temps and the high-side pressures get progressively higher with higher ambient temps. For example, at 55 degrees F outside, the high-side pressure will be in the range of 49-123 psi. At 120 degrees F, the high-side pressure could be 300 psi.

Feel along the high-side line from the compressor (discharge) line (without burning yourself), to and out of the condenser, and then along the line leading to the orifice to see whether there is a point where you feel an abrupt drop in temperature. Normally, the high-side line temperature will gradually cool till reaching the orifice, then there will be an abrupt drop in temperature (condensation or a light frost could appear after the orifice).

It sounds like you may have a blockage in the high-side line, somewhere between (or at) the orifice and the discharge port on the compressor.

Let me know,

Jim

phill0072
07-26-2008, 15:00
Thanks for the reply jim, I was thinking a restriction at the orfice tube " had a clogged one on my old van" I thought 450 was way to high. I will take your suggestion on feeling up the hoses :D:D Only problem is the high side gas line out of the compressor is a pain to get to in these vans. And so much for not burning myself on that line. I was changing my cigar lighter fuse last summer and it got me good, it was 100 degrees outside and truck was idling with a/c on and it got me good:eek::eek::eek: I still have the mark on my forearm. I think maybe I will use a themo temp gun on the lines and condenser. Any idea of what the high side line temp should be comming out of the compressor into the condenser??? I was thinking last year when I burnt myself that the line was way to hot.

More Power
07-26-2008, 15:12
Some of these systems contain an inline filter in the liquid line between the condenser and the orifice, which is there to prevent contamination of the orifice (due to junk in the line or a compressor failure). If there is a marked temperature difference before/after that filter, it is plugged. The filter is about 1" or in diameter and about 3" long. It can be serviced - the body screws together with a fine screen inside.

The high pressures you're seeing would seem to indicate a blockage - either due to crap in the system or the orifice is icing up (which could indicate the presense of moisture in the system).

Jim

JeepSJ
07-27-2008, 08:46
Go post on the forums over at www.ackits.com. They should be able to help you figure out the problem. You could also probably find a good shop through there.

leolkfrm
07-27-2008, 17:48
Should you get to western ny neals radiator in tonawanda is good... however, are your electric fans and clutch fans engaging as they should?

phill0072
07-29-2008, 07:55
Yes to the clutch fan engaging and this van does not have a electric fan. I got my themo temp gun out and was shooting the a/c lines and here is what I have come up with. The high side line out of the compressor the rubber part is running about 198 degrees then it goes into a metal fitting where it drops to about 180 then goes into the condenser where it steadly losses temp and when it comes out it is about 124 degrees, then goes thru a fitting that is used if you have rear a/c "but I don't" then into the evap which I can not shoot. Line out of evap to accumalator is about 100 degress and there is condensation on it as there should be, then the line from accumalator to the compressor drops temp evenly till it goes back into the compressor. I am thinking since I am showing a high high side pressure the blockage would have to be down stream of the port "between the port and the compressor which would leave that fitting or the evap or the accumalator". I would think that if the blockage was before the port then I would have a low pressure at the port does this make since??? also I can't find the orfice tube I know what the one on my old van looked like but there is nothing on here that looks like it. Can anyone tell me where abouts it maybe and what does it look like nowadays. The only thing that I think the orfice tube could be would be that fitting that I am thinking is for the rear a/c. could this be it?? this fitting is located on the high side line about six inches down stream of the high side port then the line runs into the evap box.

More Power
07-29-2008, 12:14
http://www.thedieselpageforums.com/photopost/data/500/ac09c1.jpg

This is a portion of the A/C system used in a 2001 GMC 2500HD. The orifice is contained within the fitting just above the arrow in the photo. The orifice is the dividing line between the high pressure and low pressure side of the system.

There should be a marked temperature difference before/after that orifice - if it's working correctly.

Jim

phill0072
07-29-2008, 13:31
Thanks for the photo jim mine is set up differently, my low side port is on the accumulator. I don't see anything like your orifice tube on here. The fitting I was referring to is in your pick just above your fuel filter housing. I will keep looking it has got to have a orifice tube or a expansion valve some where on this darn thing. If I can find my camera I will take some pics of the system again thanks for your continuing help in this saga:D:D

More Power
07-29-2008, 14:26
Thanks for the photo jim mine is set up differently, my low side port is on the accumulator. I don't see anything like your orifice tube on here. The fitting I was referring to is in your pick just above your fuel filter housing. I will keep looking it has got to have a orifice tube or a expansion valve some where on this darn thing. If I can find my camera I will take some pics of the system again thanks for your continuing help in this saga:D:D


The A/C line fitting above the fuel filter housing is simply a joiner. It allows bolting the lines together.

The orifice has to be inline in the tubing between the condenser and where that line enters the firewall.

Once the line passes through the firewall, the cold refrigerant circulates through the evaporator (the heat exchanger that the fan blows through to make the cold air). So, the refrigerant has to be cold before it reaches the evaporator.

Jim

phill0072
07-29-2008, 16:07
Ok the orifice tube must be located in the evap box, go figure:rolleyes: I will take a look at that tomorrow or so. When I was shooting the line temps I noticed that the temp's coming out of the condenser then up to where the high side port is and then thru the joiner then into the evap box were steadily dropping in temp. I would have to say that if might of lost 5-10 degrees over the whole 2 feet of tubing. I was hopeing not to have to get in to the evap box but it figures ain't nothing easy to do on this van. :eek:

madmatt
08-02-2008, 22:06
I'm in Southern Indiana about 25 miles from Louisville, KY. Interested in stopping by??? Just seen the same problem on a gas powered express van. Has the compressor been replaced recently by chance????

phill0072
08-03-2008, 15:39
No it has the orginal compressor on it. I found what the problem was, the orifice tube was not manufactured correctly the screen had most of its holes not drilled out. Only about 1/4 of them where drilled all the way thru :eek: so who ever or what ever "could be a machine" that put it together was not paying attention. I took some pics of it but the resolution is not that good on my camara so they are not even worth putting up. thanks for all the help from everyone. And by the way if anyone reading this owns a express van the orifice tube is hidden in the evap box. how nice for gm to do that for us:eek::eek:

phill0072
08-03-2008, 15:44
Hey madmatt are you a diesel shop by any chance???? I am looking for a good one, and I am in scottsburg, seymour and columbus quite often I haul alot of stuff in and out of their for cummins.:D

madmatt
08-03-2008, 19:36
No I work for a GM dealer. We have a location in Scottsburg actually. John Jones GM City is the name of our Locations. I'm at the Corydon location.