home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 06-09-2018, 01:20 AM   #1
leecatd8209
Newbie
 
Join Date: Jul 2015
Location: NCPA
Default 1990 NA 240 AC inop

I recently picked up a clean, low mileage 240 and I'm in the process of shining it up, and making everything work. The latest project has been the AC, but it's been a struggle. I had some minor success with it earlier in the week. At one point, charged with r134-a, it worked somewhat poorly for a short time. After some reading I'm wanting to use air duster, but right now everything is screwed up. I've changed the compressor oil, receiver/drier, and added R-134a fittings. The weather here is mid 90s with 95%+ humidity every day.

Currently:

I had everything evacuated, it seems to hold pressure well, pulled a vacuum for about an hour, then let it sit. After I kill the vacuum pump it slowly creeps up to ~18psi vacuum, but then holds there indefinitely.

When I charge the system the compressor kicks on, and then never shuts off. I added the appropriate amount of refrigerant and my low side has almost no pressure, the high side is at 130lbs all the time. At rest they both equalize at ~90lbs. I've tried undercharging, overcharging, air duster, R-134a, no difference. Hot ass air out the dash.

When it's charged the the proper pressure the thermal expansion valve before the evaporator is very cold, and covered in condensation, but the evaporator is warm. I'm sure this is some of my problem, but my pressures aren't really indicating that. (unless they are, I'm pretty new at this).

Anybody have any ideas? Maybe there's an AC guru in here? If I left anything important out let me know, and I'll get you some info.

Thanks!
leecatd8209 is offline   Reply With Quote
Old 06-09-2018, 02:33 AM   #2
dartheyeball
Board Member
 
Join Date: Aug 2012
Location: Overland Park, KS
Default

Have you checked the orifice tube to make sure it isn't clogged and is also installed in the right direction? When I replaced the ac compressor on my 740, I also replaced the reciever driver and oriface tube. I charged up the system and it worked poorly. Turned out that the orifice tube was installed backwards. I also replaced my condenser as well.
dartheyeball is offline   Reply With Quote
Old 06-09-2018, 11:52 PM   #3
leecatd8209
Newbie
 
Join Date: Jul 2015
Location: NCPA
Default

Quote:
Originally Posted by dartheyeball View Post
Have you checked the orifice tube to make sure it isn't clogged and is also installed in the right direction? When I replaced the ac compressor on my 740, I also replaced the reciever driver and oriface tube. I charged up the system and it worked poorly. Turned out that the orifice tube was installed backwards. I also replaced my condenser as well.
This system uses a thermal expansion valve instead of an orifice tube. I'm suspecting it's blocked up for sure.
leecatd8209 is offline   Reply With Quote
Old 06-10-2018, 04:02 PM   #4
dl242gt
Can play the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

I had the expansion valve clog on an 84 turbo I used to have. A shop cleared it with their machine. Worked great after clearing the blockage and a fresh batch of R12.
__________________
Dave,
1982 242 turbo. 340k miles. Good stuff and lots of rust.
1993 245 Classic, 417k miles, enem V15. IPD bars and chassis braces. Simons sport exhaust from Scandix. sbabbs ezk chip. Been a good road warrior. Genuine Volvo rebuilt leaky M47.
dl242gt is offline   Reply With Quote
Old 06-10-2018, 04:34 PM   #5
leecatd8209
Newbie
 
Join Date: Jul 2015
Location: NCPA
Default

Quote:
Originally Posted by dl242gt View Post
I had the expansion valve clog on an 84 turbo I used to have. A shop cleared it with their machine. Worked great after clearing the blockage and a fresh batch of R12.
I wish R12 were still available easily. I even have some at my old shop, but that's 1800 miles away. Air duster supposedly behaves much like R12, so hopefully once I get stuff straightened out it'll work just fine. I've got a leak somewhere now, so it's time to find that.
leecatd8209 is offline   Reply With Quote
Old 06-10-2018, 05:08 PM   #6
90volvo
Board Member
 
Join Date: May 2017
Location: Eldorado Springs Mo.
Default

I tried air duster on my own car. I did not get much cooling out of it. you can find R12 on craigslist. Myself I like duracool. Its super hot here in the ozarks and im getting 38 degrees at stop lights. I have original equipment except dryer and expansion valve. I have the exp. valve set at 3 turns out.
90volvo is offline   Reply With Quote
Old 06-10-2018, 05:10 PM   #7
90volvo
Board Member
 
Join Date: May 2017
Location: Eldorado Springs Mo.
Default

original dryer bag could of broke and put beads in your system which wold plug you expansion valve. I know happened to me once. Where are you located.
90volvo is offline   Reply With Quote
Old 06-10-2018, 10:23 PM   #8
jjona5
Board Member
 
Join Date: Nov 2017
Default

Quote:
Originally Posted by 90volvo View Post
original dryer bag could of broke and put beads in your system which wold plug you expansion valve. I know happened to me once. Where are you located.
This happened to my 90.
jjona5 is offline   Reply With Quote
Old 06-10-2018, 10:43 PM   #9
leecatd8209
Newbie
 
Join Date: Jul 2015
Location: NCPA
Default

I'm in South Texas, it's hot as balls all the time. I put a new receiver drier in it already as part of the "retrofit". Now that it's empty again I'm gonna take a look at the expansion valve setting, change some o-rings, and order some duracool. It was my next choice after the air duster. I had it working on R134-a, but not well.
leecatd8209 is offline   Reply With Quote
Old 06-10-2018, 11:09 PM   #10
jjona5
Board Member
 
Join Date: Nov 2017
Default

I'm in Houston. I installed a newer universal parallel condenser in mine as the old one had a hole and it does pretty well with the duracool.
jjona5 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 06:11 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.