Anyone ever have to replace the expansion valve on their A/C? I'm looking at the procedure and it scares the bejesus out of me. If I'm reading right I would have to remove the steering wheel and whole dash?

 

It's not a job that anyone would want to do that wasn't experienced in A/C work. May I ask why you want to replace it? The expansion valve is usually in the engine compartment side of the A/C system in most vehicles. I've never had experience with it in an RX but I would be a little surprised if it was buried like that, but anything is possible. I have the factory manual on CD (DVD?) but don't have time right now to look it up. I wouldn't try it unless you're experienced and have all the equipment, which would be a LOT.

 

The A/C compressor locked up. When I replaced it it had no oil in it. After vacuuming the system down and refilling I was surprised that I got no cooling whatsoever. I hooked a set of gauges up and got readings of 90 psi and a complete vacuum on the high and low side ports, respectively. The readings should have been 210 high and 30 low. I read somewhere that a vacuum on the low side and a low reading on the high side usually means a blockage somewhere in the system.
Well I found a blockage, or at least part of it. When I drained the refrigerant for the second time I noticed very fine metal shaving coming out of the high side port. I then pulled the condenser and checked the receiver/dryer. This is what I found:

Unfortunately the high side port is after the condenser which means some of the shavings I saw when draining had to have gotten past the filter and desicant bag shown in the above image. I'm scared to death if the expansion valve is blocked. I find myself in a real hard place right now. Do I go ahead and replace the condenser/receiver/dryer and hope for the best or should I try to backflush the system in case something got past and is on its way to the expansion valve?

 

Is that a hole in the bottom of the desicant bag? It's so black in the picture that it's a little hard to tell but if you got shavings past the filter and desicant bag, it must be a hole. If you have metal in the system at all, you MUST do a complete flush. Unless you want to test how long a compressor will run with metal running through it. I would even be concerned that the new compressor may have already picked up some. NOT good! If the compressor that you removed had NO oil, you needed to stop right there and say "where did the oil go?" An A/C compressor doesn't use oil, so there must be a leak somewhere that let it out and it shouldn't be hard to find because the oil is ALWAYS the 1st. thing that comes out. That's how you can tell you have a Freon leak even before it gets low enough to quite. You're gonna have to back up and go at this in the right order or you're simply gonna be doing it (with compressor) all over again.
Also, 210 is high on the high side unless the day is a little warm. (Then it's OK.)

 

fNeither the bag nor basket have a hole. I don't know how but shavings definitely got past . Fortunately I don't think anything got to the new compressor. There was no evidence of shavings on the low side line when I broke it. I'm still debating on putting an in-line filter on.

A flush has already been performed. I went against recommendations and back flushed from low side through the expansion valve to high side. I've read it is not recommended to flush an expansion valve. Here's hoping the valve has a pre-screen filter that caught all the crud. For now I'm waiting on the new condenser to arrive.

As for the missing oil, I believe it leaked out at the compressor. I couldn't find evidence of a leak anywhere else.

I will probably go buy another can of the flush today and see if it comes out cleaner the second time around. Right now I'm hoping for the best and planning for the worst.

 

Why did you decide to change the condenser? Because the factory manual says to under those circumstances? I don't really understand why the flush wouldn't clean the condenser just like the rest of the system. From my expereience it was never common practice to replace the condenser in the case of a contaminated system. Maybe the RX condenser is constructed differently so that it's difficult to get all of the contamination out, I don't know.
If the oil all leaked out at the compressor, it must have been an oily mess because a little oil goes a LONG ways. Do you have a sniffer? I would make sure you don't have a crack or leak somewhere else after you've put a can in before you do the full charge. I've made that mistake (assume I found the problem somewhere else and overlook checking for additional leaks) a couple of times and only cost me more time and frustration. Shame on me!
My DIL's '99 RX (built May, '98) still has the original charge at 165K mi. +, even though I had the complete front drive assembly out. I just unbolted the compressor, tied it to the side and didn't have to break the lines. Nice and cold yet too.
Get a brass ball filter if you can. Definitely nothing will get past that. If it clogs, it will quit working because of blockage,but won't let anything past.

 

I'm changing the condenser because it's so dirty it's not worth trying to clean. One less thing I have to wonder about contaminating the system.
I'm almost certain the oil leaked out at the compressor. But since the compressor sits about a foot from the engine oil filter that area is already grimy. The whole system takes just 7 fl oz of a very light weight oil so I don't know that it would be real noticeable especially if it comes out over the course of a week or even month.
As far as I know the wife's RX, which is also a '99, was still on it's original charge at 175k mi when the compressor went.
I've got a pancake style in-line filter. Part of me doesn't want to put it on even though I know I really need to. Between having the alternator, compressor, and condenser out this is shaping up to be a very lengthy job. The time to add the in-line filter is only adding to the torment.

 

BJB, 7 ounces of oil isn't a lot but the way it collects dirt, even an ounce or two over a year would produce a very noticable leak. Additionally, when a compressor leaks it's almost always at the clutch seal which is at the end away from the oil filter, so you should't normally ever get a comp. leak confused with the oil filter "drool". I'm still concerned about where all the oil went if the comp. was bone dry and not a very obvious sign of where that much oil went. If you have a sniffer, I encourage you to do a leak check when you're all buttoned up before you do a full charge, or AT THE VERY LEAST, add a half can, record the STATIC pressure and after a day check the STATIC pressure again, AT THE SAME OUTSIDE AIR TEMPERATURE. Temperature affects "coolant pressure".