• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

A/C no cold air after total rebuilt

T

Tonybeirut

NAXJA Forum User
Location
Lebanon
Guys.
I totaly rebuilt my a/c compressor from scratch...
It worked fine for almost 3 month.
Yesterday it was blowing cold air normally, today I turned my heater on to the max for about 2 minutes then I turned the a/c and no cold air at all.

Checked the door leveler under passenger side and it's working both ways to the end.
A/c clutch is engaging, efan turns on, serpentine is not loose, freon is circulating (can see it circulating in the guage/eye checker), both lines that goes to the havc are warm not cold.

What else I have to check/fix and does activating the heater caused that problem.?
Thank you
 
make sure the blend door is acutally closing completely. the lines from the evaporator should be hot to the expansion valve, cold after the expansion valve exiting the evap should not be hot, more like warm.

sounds like the door didn't move since air will always flow over the evap, this is to dehumidify the air.
 
The heater won't make the AC lines warm.

If you don't have gauges on it, its hard to say, but at a guess, if its pumping, but not cold, you may have lost your expansion valve.
 
I have to remove the dash to reach the blend door right?
Payed 200 last time to change the heater core hope I won't be needing that again :(
Expansion valve is the part under the compressor (the one where I can see the freon circulating)?
Learning correct parts names in english sorry. :)
 
the expansion valve is the metering device that seperates the high and low sides. my 94 is located right by the evap, engine side of the firewall. i think they are all located similarly.

the sight glass is located on the reciver drier/ acumultor. (small tank)
 
Dragonlich1961 said:
the expansion valve is the metering device that seperates the high and low sides. my 94 is located right by the evap, engine side of the firewall. i think they are all located similarly.

the sight glass is located on the reciver drier/ acumultor. (small tank)
Click to expand...

Ok got it. Mine is a 1994 too.
Just felt a bit of cool air from the vents now and when I touched the line connected to the evaporator it's a bit cooler then before. But none is cold. Dunno if this narrows the problem.
I'll put gouges tomorrow at the shop and check everything.
 
If you can see the freon moving it means you have air in the system and could also have moisture. I agree that you need to put a manifold on the system paying particular attention to the high side pressures as a high reading will mean a blockage. When you did the rebuild did you replace the receiver/dryer and vacuum the system down completely? If not it is possible that moisture in the system collected and then blocked the system when you cycled it. A/C's don't like air or moisture in freon.
 
gauge showed 60 , should be 120, so there is a leak.
when i turn a/c on it gives warm air , even the normal air flow without a/c on is much cooler
 
Tonybeirut said:
gauge showed 60 , should be 120, so there is a leak.
when i turn a/c on it gives warm air , even the normal air flow without a/c on is much cooler
Click to expand...

60 what? What units? is this R-12 or R-134a refrigerant? Gauge on what side?

R-134a should be about 35 psi low side, 220 psi High side or higher, up to a max of about 50/300 max.

Any flow visible in the sight gauge indicates it is undercharged, a leak has formed, if it was working properly before and filled and service properly before.
 
Ecomike said:
60 what? What units? is this R-12 or R-134a refrigerant? Gauge on what side?

R-134a should be about 35 psi low side, 220 psi High side or higher, up to a max of about 50/300 max.

Any flow visible in the sight gauge indicates it is undercharged, a leak has formed, if it was working properly before and filled and service properly before.
Click to expand...

R-134a. I dont remember if the compressor was off or On when he took the low side pressure and it showed 60 psi. Flow is visible yes.
 
Tonybeirut said:
R-134a. I dont remember if the compressor was off or On when he took the low side pressure and it showed 60 psi. Flow is visible yes.
Click to expand...

OK, I might add that at 100F (approximately) you should see about 90-100 psi in the system, high or low side, when it is off and has been off for say 20-30 minutes, as I recall.

There is a great AC only chat site run by experts on AC in Arizona at www.ackits.com that know a lot more about vehicle ACs than we do, but there is great info here specific to jeep AC's too.
 
Sometimes its hard to diagnose over the the Internet, do you have a full set of gauges, high and low? Cycling on low side should be 25-40 psi, I can look up better numbers but without knowing the high side... May be a leak or low charge. 60 seems too high on low side on a properly running system.
 
did freon recharge today after checking if there are any leaks at the compressor , lines, expansion valve.. nothing showed, cold air is ok now. Maybe its the ac evaporator leaking.
if i loose the freon again they will inject a phosphor liquid and see where it comes out from.
 
The electronic sniff detectors work far better than the UV fluorescent dye does and they find much smaller leaks. I had a from shaft seal leak that sniffer found that the dye did not show. We ran the AC to get the pressure up and hot, turned it off (no fans running) and sniffed it out. Try to find and borrow one
 
Ecomike said:
The electronic sniff detectors work far better than the UV fluorescent dye does and they find much smaller leaks. I had a from shaft seal leak that sniffer found that the dye did not show. We ran the AC to get the pressure up and hot, turned it off (no fans running) and sniffed it out. Try to find and borrow one
Click to expand...

I still have to remove the HVAC to do the test at ac evaporator, hard job again...
 
Best way to test for a leak, is to pull a vacuum with a vacuum pump, BEFORE you install the refrigerant. Pull the vacuum for an hour and then see if it holds the vacuum for about 12 hours. But too late for that now.
 
Ecomike said:
Best way to test for a leak, is to pull a vacuum with a vacuum pump, BEFORE you install the refrigerant. Pull the vacuum for an hour and then see if it holds the vacuum for about 12 hours. But too late for that now.
Click to expand...

The best way is to pull vacuum AND to fill the system with dry nitrogen. I have seen systems hold pressure but not vacuum and vice versa.
 
md21722 said:
The best way is to pull vacuum AND to fill the system with dry nitrogen. I have seen systems hold pressure but not vacuum and vice versa.
Click to expand...

I have seen the same with the compressor shaft seal once before as well.
 
You must log in or register to reply here.

Similar threads

M
1992 XJ A/C Air Conditioning Replacement - Parts List
Replies
7
Views
2K
Rob Mayercik
R
B
All new A/C, cool but not cold.
Replies
10
Views
1K
old_man
old_man
S
A/C compressor kicking in with heater (no heat)
Replies
4
Views
642
Tim_MN
Tim_MN
B
Dang a/c problem...
Replies
4
Views
520
bradleyheathhays
B
O
A/C not cold?
Replies
8
Views
459
Tony_SS
Tony_SS
Back
Top