• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

240 1993 A/C recharge w/ duracool overly high low side reading

Texas240

Texas240

Prius Owner
300+ Club
Joined
Jul 27, 2008
Location
Dallas, TX
First off. I know some of you purist are going to tell me not and I should only stick to what came in the car blablabla and that some of yo are going to moan and ground and grunt that its dangerous cause its a highly flammable blablabla. If I didn't have three cans of duracool and a can of duradry laying around I would use R134a.

Car currently has a 2004 lm7 in it using the stock ac compressor which turns on and off when ac is running.

the issue that lies:

Using my ****ty Harbor Freight A/C gauges which I should just chunk but whatever. Im reading 170+ psi on the low side and 150 on the high side. Im suppose to see no more then 35 psi on the low side and some where around 150 psi on the high side. First can of duradry sucked right up without any issues. First can of duracool is well..... I have maybe been able to get a 1/4 can to get sucked in then it stops or just seems to go at a extremely slow rate of suction of duracool.

The pressure is whats worrying me on the low side and not being able to get any more refrigerant to go onto the system. A friend said that the 58% humidity could be part of it but i call bull.

any ideas? Been about 5 years since Ive touch an A/C system.
 
Compressor isn't pulling it down. Is the compressor kicking on? If not you may need to jumper the low pressure switch.

Also, did you evac the system, pull a vacuum on it?

As for the new stuff going in, I've had a LOT of issues with the trigger setups you get from the chain stores. I finally found one that's a press-button type so you actually press down and it opens the valve on the can, seems to work FAR better.

Just charged the system on my wagon with straight 134 yesterday, works but not great. System pressures will be high until the compressor pulls it down.
 
gsellstr said:
Compressor isn't pulling it down. Is the compressor kicking on? If not you may need to jumper the low pressure switch.

Also, did you evac the system, pull a vacuum on it?

As for the new stuff going in, I've had a LOT of issues with the trigger setups you get from the chain stores. I finally found one that's a press-button type so you actually press down and it opens the valve on the can, seems to work FAR better.

Just charged the system on my wagon with straight 134 yesterday, works but not great. System pressures will be high until the compressor pulls it down.
Click to expand...

Compressor is kicking on and off as it should. Jumper workers too on low side switch. I evac the system for about4 hours and held a vacuum over night. Im using an actual a/c manifold gauge set with screw on connectors to the can.

I flushed the system with two 16oz cans of pressurized flush stuff. Was a little dirty and replaced the orifice tube which was ironically dirty and a bit clogged on one side. Was replaced a year ago but the system was never charged. Will see how this second go around goes.
 
Metal bits in the orifice tube? Could be the compressor is wasted. Are you getting pressure fluctuations when the compressor kicks on and off? If not I would suspect the compressor may be done.
 
gsellstr said:
Metal bits in the orifice tube? Could be the compressor is wasted. Are you getting pressure fluctuations when the compressor kicks on and off? If not I would suspect the compressor may be done.
Click to expand...

Didn't look like metal bits. Was black and brown. Different compressor, compressor that came with the lm7. Pressure does fluctuate 20 psi. Will see what comes form the flush and new orifice tube.
 
I have been doing lots of self training and hands on experience on AC recently. Got me $20 EPA 608 certification to handle R12, R134a, and R1234yf.

I was balls deep in a Ford Escape AC system yesterday that was hitting 300psi on the high side and compressor was disengaging. Customer was complaining of intermittent AC even after a recent service. Clues were it was slightly overcharged 1.7lbs came out 1.5lbs was spec. This is with a high end AC service machine. TSB's and other research showed the drier falls apart and sends chunks thru the system and causes clogs on the Escape and the Super Duty. I put it all back together, vacuumed down and got it to keep the AC compressor staying on but the pressure would skyrocket to almost 300psi on the high side, the fan would then kick on, the pressure would drop down to under 200. I also was doing temp differential tests where I was feeling for temp changes on certain areas to detect restrictions. The drier was suspect and it was hot going in and less hot going out. I was developing a test yesterday where I blew thru components with a hose in my mouth to feel for restrictions, but it was inconclusive. I don't even know how legit that test is to be honest. Still learning. I recommended a new drier since it is possibly restricted and known to fail, and also an expansion valve because it's suspect and debris make them fail when the drier dies. Please chime in about this above paragraph of threadjack if you have any help.


Back to you: did you ever get the compressor to kick on when charging? My machine charges on either, or both sides depending on what you chose. I have been trained to fill on BOTH sides. I punch in the desired weight of 134 and the desired oil injection amount, hit a button, and then go take a break.


What are your static pressures? I have seen about 100psi static on both sides in 80 degrees temps as normal. With the exception of this Escape from yesterday that had 300 psi static high side when it came in!

I theorize like Gsellster said, that compressor isn't pulling in the low side. I need more experience, but that sounds like it might be it. Did your AC work at all before?
 
ZVOLV said:
I was balls deep in a Ford Escape AC system yesterday...

The drier was suspect and it was hot going in and less hot going out.

I recommended a new drier since it is possibly restricted and known to fail, and also an expansion valve because it's suspect and debris make them fail when the drier dies. Please chime in about this above paragraph of threadjack if you have any help.
Click to expand...

+1 to new accumulator/drier. Anytime the system fails internally or is "open to the atmosphere" for any length of time with significant changes in humidity, the accumulator/drier is toast. The filter gets internally clogged and the dessicant becomes saturated. New compressor warranties require a new drier when the system has to be opened.

I have done 2 complete AC redos in my old Mercs and without the new driers I have ended up with 1 crappy system with lukewarm air and 1 with a blown compressor. The fix for both was a gut job - new compressor, accumulator/drier, orifice tube/expansion valve, new oil, refrigerant, and seals. Only way I have ever experienced.

The whole "it only needs a charge" theory is a complete myth.
 
ZVOLV said:
I have been doing lots of self training and hands on experience on AC recently. Got me $20 EPA 608 certification to handle R12, R134a, and R1234yf.

I was balls deep in a Ford Escape AC system yesterday that was hitting 300psi on the high side and compressor was disengaging. Customer was complaining of intermittent AC even after a recent service. Clues were it was slightly overcharged 1.7lbs came out 1.5lbs was spec. This is with a high end AC service machine. TSB's and other research showed the drier falls apart and sends chunks thru the system and causes clogs on the Escape and the Super Duty. I put it all back together, vacuumed down and got it to keep the AC compressor staying on but the pressure would skyrocket to almost 300psi on the high side, the fan would then kick on, the pressure would drop down to under 200. I also was doing temp differential tests where I was feeling for temp changes on certain areas to detect restrictions. The drier was suspect and it was hot going in and less hot going out. I was developing a test yesterday where I blew thru components with a hose in my mouth to feel for restrictions, but it was inconclusive. I don't even know how legit that test is to be honest. Still learning. I recommended a new drier since it is possibly restricted and known to fail, and also an expansion valve because it's suspect and debris make them fail when the drier dies. Please chime in about this above paragraph of threadjack if you have any help.


Back to you: did you ever get the compressor to kick on when charging? My machine charges on either, or both sides depending on what you chose. I have been trained to fill on BOTH sides. I punch in the desired weight of 134 and the desired oil injection amount, hit a button, and then go take a break.


What are your static pressures? I have seen about 100psi static on both sides in 80 degrees temps as normal. With the exception of this Escape from yesterday that had 300 psi static high side when it came in!

I theorize like Gsellster said, that compressor isn't pulling in the low side. I need more experience, but that sounds like it might be it. Did your AC work at all before?
Click to expand...

Compressors kicks on and off. Highly doubt thats the problem. Im vacuuming down the system on both sides and charging on low side with both low/high sides hooked up. A/C worked 6 years ago before I did the swap over to 16v not I'm on the LM7 with a modified drier with a -10 suction fitting welded on.
 
I can't tell you what is wrong from here, but I would make sure the proper amount of refrigerant is in there and then I would monitor the pressures and the compressor clutch and temps of different components of the system.

In my threadjack news, I got the Escape to blow frosty yesterday morning. Whatever I did the day before worked. I blew thru the drier, lines, and condenser with a hose in my mouth and didn't feel substantial restrictions except possibly the drier. I put the PROPER amount of refrigerant in (1.5 lbs instead of the 1.7lbs it was overcharged with) and high side pressure still would climb up to 250-300 psi, but the fan would kick on and it would drop back down to under 200 psi. I don't have enough experience to tell if that's normal operation, but the vents stayed cold and the compressor seemed to cycle ok enough. I still recommended the drier and a TXV valve as maintenance and it hopefully will bring those high side pressures back down.


I know this is a driveway fix, but you really should consider doing a professional level AC service. My machine weighs the amount of refrigerant down to .001 lbs. Also has an oil recovery feature. And oil injection feature. AND can charge on both sides which may help here.

I completely agree that anything more than about 45lbs on the low side just aint right.
 
Texas240 said:
First off. I know some of you purist are going to tell me not and I should only stick to what came in the car blablabla and that some of yo are going to moan and ground and grunt that its dangerous cause its a highly flammable blablabla. If I didn't have three cans of duracool and a can of duradry laying around I would use R134a.

Car currently has a 2004 lm7 in it using the stock ac compressor which turns on and off when ac is running.

the issue that lies:

Using my ****ty Harbor Freight A/C gauges which I should just chunk but whatever. Im reading 170+ psi on the low side and 150 on the high side. Im suppose to see no more then 35 psi on the low side and some where around 150 psi on the high side. First can of duradry sucked right up without any issues. First can of duracool is well..... I have maybe been able to get a 1/4 can to get sucked in then it stops or just seems to go at a extremely slow rate of suction of duracool.

The pressure is whats worrying me on the low side and not being able to get any more refrigerant to go onto the system. A friend said that the 58% humidity could be part of it but i call bull.

any ideas? Been about 5 years since Ive touch an A/C system.
Click to expand...


you know what else is highly flammable? Gasoline.
 
johfraser said:
Too much gas. The compressor is pumping ok but does not need as much gas as is in the system. Therefore high low-side readings.
Click to expand...

Did you even read the first post? Why the **** do I bother posting when you all can't be bothered to read. I havent even put in a 1/4 can of freon.
 
Suck down the system.
Flush it.
Replace orifice tube and filter/dryer and/or expansion valve.
Refill with appropriate oil and refrigerant.
 
Texas240 said:
" First can of duradry sucked right up without any issues. First can of duracool is well..... I have maybe been able to get a 1/4 can to get sucked in then it stops or just seems to go at a extremely slow rate of suction of duracool. "
Click to expand...

I don't normally jump in to defend someone who gets flamed by a guy having trouble fixing his own car, but I too had the same impression of your first post, generated by the above snip.

My question: What is cycling the compressor if the low side remains higher than the high side? Or am I also misreading your question...
 
Do you know what kind of compressor is on the lm7? GM R style or something newer? I had a GM truck with a 305 and newer R-style compressor act this same way. Never got to the bottom of it, but had an R style compressor act this same way on an old Merc a few years later...gutted everything and started over and had no issues.
 
badvlvo said:
Suck down the system.
Flush it.
Replace orifice tube and filter/dryer and/or expansion valve.
Refill with appropriate oil and refrigerant.
Click to expand...

This was my first idea before I even posted but I thought I would get a reasonable answer based on only able to get 1/4 can in. I would install new dryer and new suction line from dryer to compressor but I have to get onto set at 6pm at the 50 yard line at the cotton bowl for a Texas Lottery Commercial and I won't be done work till 9-12am/pm tomorrow.
 
eurotrash940 said:
Ah ha! Do you have this newer style of GM compressor? V5 or V7?

http://www.aircondition.com/tech/getattachment.php?data=NTN8UmVmcmlnZXJhbnRfQ29udHJvbF9WYWx2ZXMucGRm

Apparently, fairly common for the control valve to fail in these, causing your exact symptoms, no/little low side pressure differential, despite engagement and cycling of the compressor clutch.

Google GM RCV and you will find tons
Click to expand...

You know, I have no idea. I haven't really looked that closely into it. If Im getting the same issue after trying to refill again tomorrow after filming I'll take the compressor and start looking. Thanks for the info, I wold never of guessed this.. THANKS!!!!!!!:nod:
 
Well. Same issue just 50 psi lower. Flushed every tube and and what not of the system, replaced orifice tube, replaced dryer and vacuumed down the system for 5 hours and let everything sit for 3 days, no vac leaks.

Went to go fill the system with duracool and same thing. PSI on low side goes to 90 and high side to 120 psi. Still to high but seems way to close to be a blockage. Something isn't allowing pressure free up. I looked into it being a faulty Compressor Control Valve in the back of compressor since mine doesn't have one. Compressor is a on/off cycle compressor compared to a cycle on all the time type which happens to be more efficient.

Could the compressor be a goner from the get go or could the expansion valve need replacing?
 
You must log in or register to reply here.
Back
Top