Hello all, new to the group and hope to learn a thing or two from this forum. I have a 2000 f250 5.4 and I'm having some ac issues, I have replaced the compressor, accumulator, and the orifice . Had the system evacuated and refilled and tested for leaks and all checked good. The issue is I'm only able to get the ac out of the vent down to 70 degrees and that is at an idle, at highway speeds it is higher 80 or so. Anyone have any idea why? I also changed the blend door actuator still no help. Thank you in advance.

 

Condensor or evaporator clogged, could be clogged heater core also
hows the airflow from the vents

 

Ran thru all the vent settings and all have good air flow. One thing I did forget to mention is that the front hubs vacuum lines for the auto 4x4 are not hooked up and the lines are not capped either, could this be part of my issue?

 

No hibs being capped are fine. I've had mine removed and capped since 2007 on my 2004 f350

Is the condensor clean, free of bent fins?
Also heater core of evaporator could be dirty

 

You're going to need to do some checks under the hood to see if you have a lack of refrigeration activity or a re-heating (temperature blend door) problem before doing any more wrenching. This will tell you which side of the firewall the problem is at.

First, check the temperature of the refrigerant line between the accumulator and the evaporator core (after the orifice tube) while it's running. If it's cold (30-45F), the refrigeration system is working. If not, then get the gauges out and measure the system pressures so you can get a picture of what's happening in that sub-system.

If the line was cold, pinch off the hot coolant line that runs to the heater core. This will eliminate any re-heating. You can also set the MODE to VENT and vary the temperature **** through it's range to see if you can vary the outlet temp from slightly above ambient to very hot. If the blend door does not close completely due to, for example, a mechanical obstruction, there will be significant heating of the air when there shouldn't be.

A vacuum issue would manifest as a loss of control of inlet and outlet airflow, not temperature.

 

When servicing first generation Super Duty AC, keep in mind those evaporators are super easy to R&R. Not to mention cost is only about $50 online. If its an orig 2000 evap the fins are prolly full of hair, dirt and lord knows what. When working properly that AC will be icy cold.

 

EXTERNAL contamination of the evaporator won't cause his symptoms. Besides, he said he already replaced it.

 

I have not replaced the evaporator nor have I opened up the housing to check its condition.

 

Ah, I misread your post. You did say "accumulator" which I misinterpreted, probably due to insufficient coffee.... or beer.

In any event, the evap isn't likely to be your problem unless clogged internally. Check the lines like I said for the reason I gave.

 

So here are my temp readings 93 before the orifice, 83 after. Condensor temp in 109, out 103. Temp at accumulator from compressor taken right after the rubber hose is 89 at the connection to the accumulator is 69. Temp coming out of vent is 60. Temp outside is 77 with 81% humidity.

 

Then continue as already advised to do. The refrigeration system isn't working (very much). Do a quick visual check to see if the engine cooling fan is working correctly and that it's actually pulling air through the condenser. Look at the compressor clutch and see if it is actually engaged and spinning the center shaft of the compressor.

It might also be insightful (for us) for you to go back and tell why you opened the can of worms you've now got.

 

You have a 17 degree drop across the evap with 87% humidity. It sounds more like the evaporator is too busy taking water out of the air than cooling the cab. FWIW, a 20 degree drop is pretty close to normal on most ac systems. A 25 degree drop is outstanding but at max performance.

 

The reason was that The ac was not working at all, the compressor was not kicking on i took truck and had it tested and had plenty of freon in it. Had the system evac and changed the parts took back and had it filled and pressure tested. Just opened up the evap housing and visually checked and it was clean no debri at all.

 

How did you get a 17 degree drop across the evap if the compressor wasn't kicking in?

 

I think he was answering my question about the prior history.

FWIW, a 17-25 degree delta across the evap is okay if the inlet is actually cold, but not when the inlet is almost 70 degrees.