SDL: low AC output (R12)
 

My 300SDL shows relatively high temperatures at the vents.
Temps are not going any lower than 10 -12C (50 -54F).
I have had the system apart, cleaned, new compressor, new condenser, new evap. and filled with R12. But maybe some air found its way in.
I already topped off one can R12 but still some bubbles at the glass and the pressures already high with not much improvement.
Can there be air in the system?

What would be decent temperatures at the vent on the stock system for the SDL?

Location: I am in Oman, Middle East with high ambient temperatures (recently 110/120F). Here is no one around who could vacuum, recover the R12 and refill. But I have another 4 cans with me, I also have gauges and a vacuum pump.


Martin

Honestly 50* out the vents with ambient temps of 110* is pretty good. I wouldn't expect much more than that.

Did you replace the dryer or expansion valve as well?

I did replace drier and evaporator with expansion valve with the new condenser.
In this country the SDL AC is not enough I have to say and I don't understand why there are still bubbles at the sight glass.
Are there any tests I could run?

What is your high and low side pressure readings?

Bubbles can mean low charge or leak.

This vent temp is at what ambient temp?

if you pressure tested free of leaks, vacuumed it out, and charged with the correct weight of R12, the coils are clean and new, the aux fan is running... it's doing all it can do.
the SDL has which compressor? sanden?

bubbles mean the liquid column of refrigerant is not solid. it's either low on refrigerant, or the ambient temp is above the design... (110°F certainly qualifies) what's the high pressure? what's the condenser liquid temp? I would do everything in my power to VERIFY zero outside air is mixing in.

At 110F., the high side pressure is going to scare you if the electric fan is not running. That's the first thing to check.

It might be possible that the system is low on R-12 with high pressure that appears a bit too high, when, in reality, it's fine at that temperature.

That compressor is quite capable in the SDL and I would expect the system to achieve 40F. at low fan speed at those ambients.

oh, and yes, if air or water is still in the lines, that will also show up as bubbles...

126 A/C Charts:

These might be helpful... didnt see one for the 603..

http://i.imgur.com/8Z5Tql.jpg

Based on a 95F (35C) outdoor temp, one should see between, 55-66 F depending on humidity.

Based on a 77F (25C) outdoor temp, one should see between, 48-53 F depending on humidity.

NFW those charts are accurate for the 603's Nippondenso compressor.

At 25C outdoor temperature, the Nippondenso will absolutely freeze the evaporator with air vent temperatures that are -2C.

At 30C. outdoor temp., the vent temp will still remain under 5C. with high humidity.

I'm not disagreeing with you, just posting the charts I found..

The 603/103's have the 10P15C compressor, the 116/117 have the 10P17C

IIRC, the 17C is a larger displacement unit, shouldn't it cool better than the 15C?

i was doing some AC research, when i came across some info that i believe answers your question in post#1 about seeing bubbles in the dryer window.

from the FSM:
"Note: An accurate check of the charge is not possible using the sight glass. At higher ambient temps(greater than 35C/95F) some bubbles may be visible with correct filling quantity."

I'm not quite sure what these numbers refer?

The 617 typically uses an R4 compressor and the charts appear to be a bit high even with that unit.

The 603 uses a completely different and much larger Nippondenso which does a much better job at cooling than the charts would suggest.

I think I had 225 - 250 psi on high side at maybe 100F ambient, but I need to verify that.

aux fan is running well. Correct amount of R12 I am nor so sure. i think I charged more but I am always a bit uncertain with the old cans...they sometimes seem to be low on R12.
I believe high side is around 250psi at 100F-110F ambient. Outside air is not mixing here.
I can see bubbles at these ambient temperatures...it is never below these temps right now and I see bubble all the time.
No idea about the condenser liquid temps. I can measure. Where? At the out let to the drier? I have a infrared thermometer.