88 burb A/C issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Krosati · 05-19-2004, 03:26 PM

I recently replaced the compressor, condensor, accumulator, orfice tube, rear expansion valve, and belt on my truck. It blew good and cold (60 degrees at the vent with the doors open) for two days. Now the vent temp is 80 degress but a check with the hand held press on guage says the system is charged at about 40psi. WHat went wrong? Did I overfill (3.5 cans of recharge)? Do I have a leak?

eaglelox · 05-19-2004, 08:40 PM

Did you pull a vacuum or evacuate the system which evaporates all the moisture inside, Water can damage your drier and whole system by turning your refriderant to a hydrocloric acid when they mix. Did you change your dryer?

**kwmech** · 05-20-2004, 12:52 AM

My burb with front and rear AC takes a lot more than 3.5 cans. It still may be low on refrigerant

Jonboy · 05-20-2004, 08:39 AM

60 at the vent is a little warm yet. Are you using R134, or R12? I would bet it is undercharged. A can is only 12 oz. , and the system is supposed to take 5.3 lbs. ( a little over 7 cans) if you are using R12.

Grim Reaper · 05-21-2004, 09:48 AM

Did you add Pag oil when you went to R134> If you didn't the coolant becomes acidic and whll eat through the O rings and possibly the hoses as well ad the Drier that was pointed out. My Dual A/C burb take 3 cans of R134 from the point it is low enough that it trips the switch. I need to find the leak because I have to add a can every couple months but 134 is still cheap and to fix the leak means I need to vac the system and extra expense.

Head pressure on 134 is much higher then R12 and still doesn cool as well. Even so it should give you a center vent temp around 45-50 with good airflow in the condensor and 1500RPM. R12 would be around 35-40.

Krosati · 05-22-2004, 08:52 PM

Th system was evacuated and every component was replaced except the front and rear evaporator coils and the lines.
I did charge with r134a. The kit included 3 cans of refridgerant/oil. I installed the first two cans upside down to add the oil, then used the last can and 1/2 of another right side up. Like I said, it blew cold the first 4 or 5 days then started blowing warm.
Can I add more cans of 134a with out fear over overcharging the system?

**kwmech** · 05-23-2004, 10:12 PM

Definately sounds like the system is low probly gonna take 3 more cans.

Krosati · 05-26-2004, 10:55 AM

So if I add the three cans, and it blows cold, then problem solved?
Or do I need to seek professional help because it did blow cold for a week then got hot.
I did add a can of charge with dye in it to look for leaks, but so far, nothing shows up.

Krosati · 06-05-2004, 01:13 AM

I found the leak, it's the large (low pressure side) hose at the firewall for the rear a/c unit. Not cheap to replace but I can get the rubber replaced if I remove the entire line. I just hope I can without damage to the fittings.

I put a hose clamp over the crimp fitting that is leaking, it seemed to slow down the leak as I am still getting 70 degree temps from the vent with 95 plus ambient temps.
I still think it should blow colder though.
I was able to add 4.5 cans this last time so I guess It is still undercharged.
After I replace the line, I think I may need to seek professional help. (for the truck that is!)

05-19-2004, 03:26 PM	#1
Krosati Registered User Join Date: Jul 2003 Location: Texas Posts: 49	88 burb A/C issues I recently replaced the compressor, condensor, accumulator, orfice tube, rear expansion valve, and belt on my truck. It blew good and cold (60 degrees at the vent with the doors open) for two days. Now the vent temp is 80 degress but a check with the hand held press on guage says the system is charged at about 40psi. WHat went wrong? Did I overfill (3.5 cans of recharge)? Do I have a leak?

05-19-2004, 08:40 PM	#2
eaglelox Member Dude Join Date: Aug 2003 Location: reno,nv,usa Posts: 191	Did you pull a vacuum or evacuate the system which evaporates all the moisture inside, Water can damage your drier and whole system by turning your refriderant to a hydrocloric acid when they mix. Did you change your dryer? __________________ Steve 1978 K20 Burb, 4" lift, 33's, 350 Eaglelox@Hotmail.com

05-20-2004, 08:39 AM	#4
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	60 at the vent is a little warm yet. Are you using R134, or R12? I would bet it is undercharged. A can is only 12 oz. , and the system is supposed to take 5.3 lbs. ( a little over 7 cans) if you are using R12. __________________ 1974 Jimmy- 5.3/4L80e/NP241

05-21-2004, 09:48 AM	#5
Grim Reaper Registered User Join Date: Jul 2001 Location: Atlanta GA Posts: 1,704	Did you add Pag oil when you went to R134> If you didn't the coolant becomes acidic and whll eat through the O rings and possibly the hoses as well ad the Drier that was pointed out. My Dual A/C burb take 3 cans of R134 from the point it is low enough that it trips the switch. I need to find the leak because I have to add a can every couple months but 134 is still cheap and to fix the leak means I need to vac the system and extra expense. Head pressure on 134 is much higher then R12 and still doesn cool as well. Even so it should give you a center vent temp around 45-50 with good airflow in the condensor and 1500RPM. R12 would be around 35-40. __________________ Grim-Reaper 70 Pontiac LeMans Sport Convertible, worlds longest resto in progress Looking for 71-72 2wd Blazer or Jimmy Project

05-20-2004, 12:52 AM	#3
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,463	My burb with front and rear AC takes a lot more than 3.5 cans. It still may be low on refrigerant

05-22-2004, 08:52 PM	#6
Krosati Registered User Join Date: Jul 2003 Location: Texas Posts: 49	Th system was evacuated and every component was replaced except the front and rear evaporator coils and the lines. I did charge with r134a. The kit included 3 cans of refridgerant/oil. I installed the first two cans upside down to add the oil, then used the last can and 1/2 of another right side up. Like I said, it blew cold the first 4 or 5 days then started blowing warm. Can I add more cans of 134a with out fear over overcharging the system?

05-23-2004, 10:12 PM	#7
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,463	Definately sounds like the system is low probly gonna take 3 more cans.

05-26-2004, 10:55 AM	#8
Krosati Registered User Join Date: Jul 2003 Location: Texas Posts: 49	So if I add the three cans, and it blows cold, then problem solved? Or do I need to seek professional help because it did blow cold for a week then got hot. I did add a can of charge with dye in it to look for leaks, but so far, nothing shows up.

06-05-2004, 01:13 AM	#9
Krosati Registered User Join Date: Jul 2003 Location: Texas Posts: 49	I found the leak, it's the large (low pressure side) hose at the firewall for the rear a/c unit. Not cheap to replace but I can get the rubber replaced if I remove the entire line. I just hope I can without damage to the fittings. I put a hose clamp over the crimp fitting that is leaking, it seemed to slow down the leak as I am still getting 70 degree temps from the vent with 95 plus ambient temps. I still think it should blow colder though. I was able to add 4.5 cans this last time so I guess It is still undercharged. After I replace the line, I think I may need to seek professional help. (for the truck that is!)



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