'04 AC orifice tube location

[getdealtwith]

Gents, is the encircled location in the attached pic where the AC orifice tube sits? Thx

 

[Hamfisted]

No. The Gen2 Expy's have expansion valve systems, no orifice tube. What problem are you having ?

Front expansion valve ....






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[getdealtwith]

It's an 04 Navi but the system is probably identical. The air temperature coming out of my vents isn't cold enough, 50F+ degrees at 82F outside, about 10F too high. Warmer at higher outside temps. This is after a complete overhaul: new compressor, dryer, condenser, expansion valve, o-rings, recharge. I assumed they (ASE certified shop) just didn't replace the orifice tube causing a blockage on the high pressure side. From videos I've seen, this location is where it's located in 1st gens.

 

[getdealtwith]

The temperatures were measured inside the vent and while driving for 10 minutes with the AC turned on BTW. The evap core fins are most likely dirty and somewhat blocked but I don't know if that has a huge impact on system performance.

 

[Hamfisted]

Do you have a manifold gauge set that you can read your pressures with ? They might've just not put enough freon in it, but you'd need to read the pressures to tell.

If you want to clean your evaporator you can drill a small hole in the HVAC box just below the glovebox and spray some of that Coil / Evap spray cleaner ( Home Depot ) onto the evaporator through the hole and it will foam clean the junk off it and wash out the box drain hole through the firewall. Just seal the hole with some black duct tape when you're done. Here's a pic . Don't place the hole further left or you risk damage to the evaporator.









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[getdealtwith]

Perfect. I was wondering where a good access point might be... Have you ever checked - with a borescope camera perhaps - how well this stuff was able to get solid matter off the coils without physically rinsing them? I've seen how plugged up the can get on the intake side. I'll try to get in there and take some pics afterwards.

I don't have gauge set BTW.

Thx!

 

[getdealtwith]

Ok, so I got in there and the coils look really clean. Granted, it's the back side so I sprayed them with the cleaning foam but haven't noticed any improvement in performance. I'd already topped off with freon a bit so next step needs to be to get a gauge set or have the pressures looked at again to diagnose. I got a brand new fan clutch in there as well and the condenser and radiator fins are clean.

 

[Vincent Vega]

@getdealtwith Seems like you have replaced most of the AC system. sounds more like a freon leak that the shop missed, but if you don't find problems after double checking the pressures, and can't get the shop to back up their work, you might check the blend doors. These trucks have issues with those. They are vacuum operated, and have little plastic gears in them. The plastic gears go bad with time, and vacuum leaks can cause malfunctions. There are two blend doors behind the dash, one for distribution (panel/floor/defrost, etc) and one for temperature control. Two more in the passenger rear wheel well behind the trim for controlling the rear HVAC (I have replaced those each twice, PIA). Let us know what you find out.

 

[getdealtwith]

Thanks. I previously fixed the vacuum line that connects to the heater valve and that addressed a problem with air not blowing from the front vents intermittently. I'm not hearing any clicking noises from the dash or rear ac blend door actuator.

I'll have them check the pressure again but if there's no leak, logically, the only remaining possible point of congestion are the evap coils. They sit right behind the orifice tube and that usually only gets clogged with aluminum debris from a failing compressor. They said they replaced both and I typically trust them because they share all old parts with me if I ask.

If the pressure ends up checking out, I might take it to another AC specialist for a 2nd opinion. Summer is coming and I need this thing to cool the truck properly when we cross the desert.