Hey guys, I serviced my cd7 accord daily and had noted previously my ap1 had some cooling issues under 4k rpm, blows pretty much hot air on you. Cools great after you get into VTEC. I got out my gauges after pulling the vacuum on the cd7 and realized my pressures were 150 low/150 high. Got a can of refrigerant dye and went to pull it in and noticed nothing moving through the sight glass. I opened the low side. Then tried the high side neither took the fill. I set the 6oz can upside down and brought up the rpm. It took the can but no pressure change. I suspect a clogged oriface tube or expansion valve. I've read the FSM on the expansion valve and id like to do a back flush first. My long winded questions are:
1. Would anything else cause equalizing pressure?
2. Would a back flush help a faulty/clogged expansion valve?
3. How long is the estimated valve replacement time?
compressor and fans kick on and it DOES cool at high rpm load, just useless at idle in Carolina summers.
thanks
Tony

 

You either have a clog in the dryer or the expansion valve. It's the only two places in the system that can cause a clog. The expansion valve requires removing the battery, and is held on with 2 allen bolts, but takes some finangling probably a good 10-15 minutes to remove.

 

So your pressures were 150/150 with the car off at ambient temperature?

 

That's correct. I'm doing valve stem seals this weekend, I'll double check. It seems to be a failed expansion valve or bad compressor. Something isn't causing the state change like it's supposed to. It was 150/150 psi at around 90 degrees

 

Sorry just read that again, those were the pressures at idle with the car running. But those were ALSO the pressures when it ran, so I assume that there is a failure since there is no change

 

Not an expansion valve or blockage, as the pressures are equal. Did you/have you before serviced it with it running and the can upside down? If so, you have slugged the compressor (bent reed valve). Here's how it works. If there is a blockage of any sort and the compressor is good, the suction side will pull down and the high side will not increase or slightly increase. Those numbers you referenced are about right for the compressor not running. If in fact the clutch is engaging, then the compressor is no bueno.

 

If the compressor was no bueno, you'd know instantly. Because it would sound like bolts in a washing machine.

 

Not true. Only if the bearings are screwed. If the reed valve is bent it just no worky. Like I said though, those pressures are suspiciously close to not running at all (clutch engagement). You can't put liquid in the suction side with it running straight out of the can and expect good results. Better method is to take the can and place it upright into a pan of very warm water to help it "boil off". Maybe it was not running when done, which is perfectly ok.

 

The thing is dead quiet at idle and it cools at 4k rpm. So I'll check out the clutch to make sure. Need to run the pressures at 4k and see if they are in fact moving when it cools.

 

If you want to know the truth, it sounds like you are undercharged and your low pressure switch is not kicking in the compressor until you get to the higher RPM's. Low charge will also ice up your evaporator.