Hey quick question! The other day in Detroit it was in the 80's and I was idling for a while and found the A/C was not keeping the cabin cool as has in the previous years. Once the rev's go up it chills down quick. The rear air was not on, I turned it on and it made no difference.

I have the Pro Air dual A/C on my 97 Starcraft Conversion and want to confirm I am just checking the pressure as a standard system of if there are not different ports to check pressure at? Here is the link to the manual for the Proair system http://www.proairllc.com/PDFs/van%20...n%20manual.pdf

Is there anything else I should check?

 

hmm... might want to check your fan clutch.

 

My 2005 E350 Chateau air is totally inadequate at idle in 85° and up. I added a clear shower curtain behind the front seats and it helped quite a bit. Now I use a window unit and generator cause I often sleep in the van on the road.

 

Isn't this because of lack of airflow over the condenser coils? That's what I always thought. I thought you had to be moving, not just idled up. I'd love to know more about this myself. It seems like I heard that electric fans on the condenser coils was the answer.

 

Yesterday I spent 5 minutes with my garden hoses and sprayed the condenser thoroughly and got some sandy grit out. The temp was 30c (80F) and humid yesterday. While not cold till driving the A/C cooled the cabin down after a few min of idle time while waiting for the kids.

Both front and back A/C were turned to full. Still gonna check the pressure.

Is there a filter that can be changed in these systems? If so I will have that done next week as I have to send van in for emissions testing.

 

Did you "check" its temperature? For years I've been keeping HVAC thermometers in dash vents. If an AC doesn't chill down near 40F it's out of whack. However to chill cabin adequately you also need a high volume of cold air.

Over years of use AC evaporators gradually collect dirt & mold. Bit by bit this restricts the flow of air passing thru & reduces efficiency of heat exchange. Since evaporators load up slowly it often escapes notice. The effect becomes most pronounced parked at idle.

There's no filter, but the evaporator acts like a sieve & b/c it's normally wet w/condensation tends to collect dust/mold. May be worth having a look. Could see in & confirm evaporator was dirty by removing blower on stock system.

Evaporator can be difficult to clean. Don't know about '97 aftermarket AC, but my '92 OEM unit had just enough hose to allow evaporator to be flipped up & out of box w/o disconnecting. Found Simple Green, special AC cleaner & garden hose inadequate. Pressure washer did the trick.

 

PST you did exactly the right steps cleaning your condenser---using a high pressure power washer has the potential of damaging it or the radiator if not carefully used!

There is a commonly used coil cleaning solution available from most HVAC sources---its designed to dissolve accumulated residues, allowing it to be be removed with no more pressure than a garden hose, about 35 psi typically. Any good detergent is just as good though---cheap dishwashing soap for example. After years of this not being a routine maintenance step it might take a few times to get the condenser really clean so persistence is the key here.

There isn't a cabin air flow filter if that's what you're asking. Do keep in mind as the humidity ramps up the apparent cooling effect is seemingly reduced while the system removes that first. Do get your system pressures tested as it might be a bit low on charge. Pro-Air is a good company as their products are found in countless conversions---I have one of their heat-only units in the rear of my work truck. Your usual pressure testing/charging ports under the dash are the only ones you need to check.

We're about to heat up and suffer through high humidity this weekend here in the mid-west---glad my A/C is working top notch!

 

I was referring to the inline filter in the A/C lines. Do these systems have one?

I realize there is no cabin filter.

 

Okay---wasn't sure PST--sorry for my misunderstanding!

You should have an accumulator that doubles as a dryer mounted between the battery and right side fender. There is a fabric bag filled with moisture absorbent that has been known to tear apart over time.

I purchased a less expensive one from Advance Auto but found it won't fit because of an extra mounting tab added to the very bottom of the unit; connections were perfect though. Space is tight so anything other than an exact match to OEM probably won't fit.

FWIW late last summer I replaced my A/C compressor, line set & orifice tube---in Max Air I'm getting about 40* leaving air temp from the dash vents at 35 MPH or higher, idling maybe 45*. This is a huge improvement since I was struggling to see 55* LAT at 65 MPH--it was very well worth the expense, hopes yours is at least this good!

 

As long as the refrigerant is at the correct level, some if this is attributed to the fact that R-134a will never cool as well as R-12. Every single vehicle I had with R-12 could freeze ya out at idle. The couple I've had with R-134a, never could do as well.

 

Don't know what's in aftermarket AC. However desiccants, receiver driers, expansion valves & orifice tubes can act as "inline filters in the A/C lines".

Trouble is "the A/C lines" are a closed system. The kinds of debris commonly trapped by their filtering effect is shrapnel from compressor failure or decomposing rubber from inside hoses ruined by incompatible fluids.

Sorry, hadn't realized you're "Still gonna check the pressure" - normally the 1st thing you need "to confirm". Without knowing high side pressure it's futile to speculate about other faults. R134a Quick Connections enable hooking up & reading gauges in less time than it takes to type a reply.

As I posted "For years I've been keeping HVAC thermometers in dash vents." this includes R12 & R134a AC. With either refrigerant "If an AC doesn't chill down near 40F it's out of whack".

While it seems to be an article of faith "that R-134a will never cool as well as R-12" that doesn't appear to be the case. IF All Things Were Equal R134a does loose a race to chill down to ~40F, but you'd need to carefully time the race to notice the win. However the only situation where All Things Are Equal is in R12 AC systems converted to R134a. Modern AC's designed for R134a compensate for the slight difference, in most cases actually over compensate.

My '98 F150's R134a AC is like other AC's, including pre '93 R12 units, in that its coldest temp is limited by a thermostat that prevents evaporator from freezing solid. Often called a Freeze Switch, it regulates how cold the AC can get by switching off compressor clutch. If not for this condensation would freeze up evaporator, stopping air flow. When working properly the lowest temp from vents is in the 35F-40F range.