After the first several minutes of driving, my wife is losing most of the cooling at stoplights, and it resumes as she picks up speed again.

It's a 2002 E-150 traveller, with the 5.4 and dual air conditioning. About 180k miles, we've had it since new, and I can't recall ever having serviced the AC in any way.

She's driving in 100-110F heat, with minimal (about 10%) humidity.


I picked up a R134a refill hose/guage, and it showed high pressure, just fairly into the red. I tried again ion a cold engine, and got the same result. Both AC on, Max, both fans on high.

What do I look at next?

If I didn't need it as recoil mass while two more kids start driving, we'd probably replace it, but I'll sleep a lot better with that steel around them (even while walking lopsided from the hole in my wallet from buying gas . . . )

 

A couple of things come to mind. If your model has electric fans for the radiator and condenser coil are they running continuously? (They should be when AC is on) At a standstill you loose most of your airflow through the condenser coil and if it's performance is marginal, there goes much of your cooling until you get rolling again. The coils in that era use micro-capillary tubes and anything will clog a path. The van needs to go to a shop that specializes in AC work. Jack legs will end up replacing everything and then give you an improper charge of refrigerant. I hate those guys....

 

For 17 years the A/C system has had absolutely no check up and you're experiencing problems now---see any correlation there?

This is the best path to pursue by far. Because this has an aftermarket A/C component system added by the converter a dealership won't be the least bit interested servicing that portion. Since the rear A/C is integrated into the factory installed system a shop specializing in bus or limousine A/C servicing is really the only good option.

Undoubtedly your systems are low on refrigerant charge and if you're not experienced servicing A/C systems the DIY fill it yourself MIGHT be marginally effective for a short time. You may have a leak that needs to be addressed and the DIY process doesn't take that into consideration or address how to properly repair it.

I would think if this van or camper is so important it would have been attended to long, long before now. Since its been neglected for so long you may need a lot of work other than just squiring some refrigerant into the system.

Good luck with this!

 

rude.

Sarcasm and assumptions are not the way to treat a guy who humbly posted on the forum for help.

I know of no maintenance checks nor procedures for any vehicle a/c system. You just fix it when it fails. And now yours seems to be failing. I agree that you would be wiser to pay a professional.

your issue could be low Freon (which seems unlikely since your test indicated high pressure), or low air flow across the evaporator/condenser.
180,000 miles doesn’t necessarily indicate a problem. My van has 340,000 and the a/c runs strong with all the original components. I have fixed a few leaks along the way though.

Keep us us posted what you do and find.

 

To properly diagnose you need a set of manifold gauges so you can read both the low and high side pressures. This could be a plethora of problems, but its hard to figure it out with only the low side pressure. I'm also starting to look into the AC on our newly acquired van, my low side is high, high side is low (thinking its either a worn compressor, or since its a scroll type, a bad control valve). At 100*F, static pressure in the system should be around 125 psi. Does it cool better if, while parked, the engine is revved to say 2000 rpm's?

 

To be clear, this is a stock, bog-standard factory vehicle. The only options on it are the larger engine, a limited slip differential (not nearly as useful as I had hoped in snow), and the factory Traveller package (custom paint color [why???], leather seats, four captain chairs, serious side-window tinting, dual air conditioners, video tape player and screen, class IV towing, and some odd and ends. It made a *lot* ore sense than a conversion, and doesn't have rust stains from aftermarket windows!).




Over the years, it's been serviced and rotated at any number of places that eagerly check hundreds of things, hoping to charge me. I don't believe that the AC has ever been one.


All that I recall over the years is two occasions of changing a coil (did the first one myself, and happily paid to not do the next one), the passenger door wind seal, having the self-alignment disabled (alignments cost amazingly less than the way that chewed the front left tie) now the side door lock currently broken (may or may not be related to its electric lock failure), passenger window disabled, any number of brake jobs, regular oil and filter changes (most by me), the radiator a couple of years ago (in hindsight, I'm suspicious. Had it not been the day before a thousand mile trip, I would have done it myself), and the transmission shredding itself (including the planetary) a couple of years ago.


I just turned it on when my wife came back with it. Turned back on a couple of minutes after she arrived, the big fan behind the radiator definitely ran constantly. I reached in with a sheet of paper, and it nearly flipped out of my hands from the flow. Is there another fan I should be checking?[/QUOTE]

The flow seemed somewhat cooler when I revved it. I suppose I should pull out my IR temp reader . . .

I'll have her try that next time she drives, once it feels warm.

thanks

 

Repeating that point... Have you looked for debris (leaves, sticks, nutshells, pine needles etc) or any blockage that may be restricting airflow through the evaporator/condenser? That can be one cause of lowered cooling capacity at lower speeds, one I've encountered myself.

 

Sorry to be unclear by by "dual air conditioners" do you mean this conversion has the Ford factory rear A/C system as installed during the original build? I'm not understanding the Traveller part figures into your situation.

My point was IF there are additional evaporators connected to the factory A/C compressor the lengthy lines running from front to rear are fairly fragile and highly susceptible to leaking especially after all those years. It could you have an issue there---this is where having a professional inspection might save you a bit of money believe it or not.

Either way do update us as you know more--and here's hoping its NOT an expensive fix!

 

The fan clutch on my van failed once, wasn't obvious either, the way you test it, insane, engine off grab fan blade, have someone crank it over, it should pull from your hand, they have fluid in the clutch, it leaks out over time, in reality, they should be replaced every few years.

 

Have you checked a price on one lately? Wow.

 

No, I think mine was $50, I was replacing the radiator and saw it as a great opportunity, when my friend removed it, it was still hot to touch, was freewheeling, pretty much no engagement by hand, thank god the radiator is big, and with rear heat it holds several gallons of coolant. I do remember my 92 Dakota with the same issue, sitting would kill the AC, fan clutch was bad, then later I had to get the charcoal canister replaced, system flush due to it had contaminated it, not cheap.
I know a guy who optimized his AC with 2 small electric fans in front of the condenser, he's a heating and air guy, used to give tips on improving your system, his is an 89 I think, the later body has so much up front, may not be room.

 

Not sure if I’m hearing you correctly but did you replace your two examples?
Im curious if it made a noticeable difference

 

Yes, I replaced it, the van gave little notice other than you could hear the roar of the fan while it was running, something that was near silent before, even feel the air rushing through the fender in the door jam when the door was open, I get complaints from passengers that my van is a meat locker, if I could only stop the vac leak switching to defrost so I could enjoy it more.

 

Wow, so you had a noticeable improvement eh?
I have two e series down here in Florida, and both are weak A/C performance at low speed/low rpm.
My employees drive them most of the time but I’ve driven both recently. I’ve noticed that revving the engine up to about 1500-1800 makes it blow colder.
Maybe its worth replacing the fan clutches...

hey regarding the vacuum issue- I had procrastinated on mine for YEARS but finally fixed it recently. It really is a do-able project. Only about $20 of parts too.
PM me if you need advice or anything.

 

I'm still here, although it's been a few days.

I've driven it twice in the heat, once on her route, and haven't seen the drop (she now describes it as from cold to cool, rather than failing).

In fact, I had to turn it *down* it was blowing so much.

I'd attribute it to the extreme heat and the limits of thermodynamics, except that we've been driving it here since '05, and this is the first time that she's reported this. (there was a problem when we first moved here, but that was a vacuum leak in the actuator that even turned on the compressor. The temporary electrical tape still has it working fine . . .).

Everywhere that I can get to shows no accumulated clogging in the radiator grill (and the radiator was replaced a year or two ago). It does park under a mesquite tree that sheds significantly.

Perhaps I can lower a camera tied to a stick to take a peek at the back side of the fan cowl for bizarre obstructions[1]. As for the fan, it should be either on or off, correct? (no varying speed when stopped?_

[1] Years ago, I had to quickly direct my wife to take the kids around the back of the car rather than the front, as an entire small bird was wedged in the grill of my Crown Victoria, going through the desert on I-80 . . .

There is definitely a heavy blow of air when it sits parked--I can feel not just the breeze but the force when I put my hand down a few inches from the fan.

Could it be that the fan clutch has gone flaky, and engages some times, but not others?