**edit** -- the AC isn't blowing cold**

Hey gentleman, me and my boys just attempted to address my broken AC. The CRX has been converted to the new system (R-whatever). We checked for leaks -- none...We checked the compressor -- seems to be doing its thing...We believe we have narrowed the problem to the expansion valve, which I understand is a PITA to access in the evaporator box/behind the dash.

Am I on the right track and can anyone give me any good tech wisdom on the operation from here?

thanks,

Jason

 

Simply stating that it's broken tells us nothing. History? Age of parts? Parts replaced? Symptoms?

Also, in any EF, the evap box is not a PITA to access.

 

what kind of pressure are you seeing on the high side and low side?

 

Good to know that it isn't a PITA to access. I've told you what I know. Assume the AC system is from a 90, or don't assume that. Assume the car is OEM...Now add to that that we attempted a professional recharge of the system and detected no leaks with dye, we found the compressor to be functioning properly...It appears to be a clog.

I would bet it is the expansion valve. I'm looking for somebody that has had this experience with the CRX.

 

Dont know. It appeared like the system took the recharge and isn't leaking.

 

Is the clutch engaging on the compressor? If the A/C isn't at just the right pressure (under/overfilled) the clutch won't engage and you won't get any cold air. Last time I had mine "professionally" recharged, jackasses put nearly twice as much in as they were supposed to. Double check that.

 

If you put gauges on the system it would tell you EVERYTHING you would need to know... It's pretty simple to diagnose these HVAC systems...

 

you cannot diagnose ac without a set of ac gauges. i think autozone loans em possibly, that way you can see if the compressor is actually doing anything and so on.

 

We had gauges on the system. The tech (my buddy) said there appeared to be a blockage. What exactly the gauges read I'm unsure...So, if we eliminate the compressor and leakage, what could it possibly be?

 

Frankly I don't see the relevance of the pressure gauges. The compressor works fine, there are no leaks, we attempted to recharge it with the best equipment, yet it won't pump cold air.

To avoid further sidetracking, and to get to the point:

1) If there are no leaks, and the compressor works, what is the likely problem(s)?

 

what is high side pressure and what is low side pressure


pressure gauges are not a sidetrack they are the primary tool for diagnosing an ac system problem. they can tell you if a compressor is near failure, if an expansion valve is bad, if you ahve too much or too little refrigerant, and more when you are really good with them.

if your "pro" said you have a blockage then it means you need to drain the system, and take it apart and clean every line out and blow air through and make sure your desiccant in the drier has not gotten into the system, make sure your condenser flows well and so does your evaporator. then put it all back together with new o-rings and vacuum then charge it up.

 

Change the expansion valve, it's not that bad to get out and it's relatively cheap. I always change it and the dryer because it's cheap insurance from having to redo all your work. Putting the evaporator back in can be a challenge but it's one of those things that takes me 5min or an hour. Sometimes it goes right in other times it fights me. It's the straps that hold it in that makes it a pain.

All you have to do is remove the glove box, undo the 2 fittings on the firewall, unbolt the straps that holds it in, then you can pull it out.

While you have it out, clean the styrofoam insulation and whatever ducting you can reach. Clean the evaporator from hair leaves, etc. I also hit it with a shot of Febreeze.

You also didn't mention if you evacuated the system prior to charging. If you don't moisture in the system can freeze and clog the expansion valve. The symptoms are that it cools for a short time, then blows warm again. Blockage can also occur if you didn't change the dryer. The bag inside that holds the dessicant can break down and release the crystals into the system.

 

Thanks bro...This is the type of response I was hoping for. I have the compression valve on order from a local parts store. You mentioned replacing the dryer. Do you know how I would request that part (thing) from a parts store? If I ask for a dryer they aren't going to understand me at a parts store.

Yes, I did evacuate the system. If I recall about the pressure, it simply didn't seem to be taking pressure. So it was low pressure but didn't go up when we charged it, indicating a clog I assume.

 

If this is indeed the case, do you know what parts I should have on hand for the process? (rebuild kit, o-rings, gaskets, silicone, solvent, air compressor)?...Thanks for the help.

 

Just ask for a dryer for a 19xx CRX, any decent parts store can find it. They should know what you're talking about. FYI: some call it a "receiver/dryer" or an "accumulator".

Go ahead and replace the o-rings with new ones for any fittings you loosened/removed. Did you install new R-134 valves? If not, you should replace the valve cores in the schrader valves (looks like a tire valve). If you did put the R-134 valves on, they bypass the schrader valves anyway.

I also hope you flushed the old oil when it was converted as the old R-12 oil is not compatible with R-134.

 

If it was me if you are changing out the expansion valve.

I would remove the box that it is in.

When I do an AC rebuild I totally clean out the ac box system as well as clean out the evaporator coils. They always work better clean.

 

Are these universal parts, or do I have to specify them (just bring the old ones in and ask for replacements)?

Yes, they are retrofitted with R-134 valves. Again, are new shrader valves universal?

Don't know if that was done originally. I do know we attempted to flush the old oil (unsure how successful it was).

 

thanks! Remove and replace the box, or just clean it? Where are the evaporator coils and what is the best method for cleaning them?

 

I bought a set of o-rings and matched up the ones I removed. They are generic. Don't worry about the schrader valves since you retro'd the valves with new ones.

When you remove the evaporator to replace the expansion valve, you have to take it out of the box. I clean the box with water. I brush the fins with a soft brush to get most of the junk out of the evaporator. I rinse it with water after I install the new valve. Don't get any water inside the system. Make sure you work clean, any piece of dirt in the o-ring will cause a leak.

Just do it, you'll see what we are talking about.

 

i actually bought an o-ring set so i had tons of different sizes to use. the dryer and expansion valve would be best to have on hand. When i last did a job like that and I had everything out i went ahead and ran solvent through each line, then water, then blew it out with air, that way i knew all the old oil was for sure out and if the dryer had popped the desiccant was not all in the system. then all new o-rings and it went back together. then vacuum it down and let it sit for a few hours and check it with the gauges, then refill, while checking with gauges, then once its at the right levels shut it down and make sure nothing is leaking....one last check with gauges and a thermometer and hopefully be done.

 

Okay, what in the world? Unless I completely missed it - I don't see where you EVER said what the problem/symptoms are.

You said the A/C is "broken" but never described your problem. That doesn't tell us anything. Not blowing cold? Not blowing at all? Compressor not engaging? Etc?

Did I completely miss some phantom post in here stating what the symptoms/problems are to have you say the A/C is "broken"?

 

Much obliged.

 

thanks bro...this is great information.

 

Perhaps "broken" was a poor choice in words. I should have used "malfunctioning", "not doing what it is supposed to do", or "not blowing cold air."...I assumed it was so obvious that it wasn't worth stating. Apparently not.

 

Of course it wasn't obvious. I can't fathom how other people were even attempting to answer your question. That would be like me starting a thread saying only that my car was broken.

Okay so the car is not blowing cold air. Is it blowing COOL air? Is the compressor engaging?

For what it's worth - R134a conversions on EF Civic's are AWFUL and will never blow "cold" air unless you live in a temparate climate where outside ambient air temps never get above about 85. R134a EF conversions in actual hot conditions which would require, well, AC are nearly downright useless.

I know from experience because two years ago I did a full-on R134a conversion from scratch with all new components (ie not just changing the fittings and shooting R134a in there) and in anything above 90 degrees or even sitting at idle for that matter my center vent temps were 70+ which is unacceptable and won't even keep you from sweating. Obviously, in Dallas, that makes the AC completely useless.

Without a radically different/larger condenser (which would be custom) in the EF you will never get good results with R134a in an EF. The systems are just so rinky to begin with that combined with the reduced efficiency of the retrofit it's not a good combo.