daltongd

Background on this is I have spend the last 3 months doing an engine swap. I had a rod knocking and replaced it with a JDM motor. In order to replace the motor I had to drop the engine and sub-frame which requires you to break into the AC system. About a month ago when I put it back in I put in a new radiator and condenser. I got it running and had a small oil leak so I ended up taking the engine back out again and replacing the rear main seal. When I open up the AC system I wrapped a clean lint free rag around the connections and tie wrapped them in place to keep the system clean. After the 2nd engine replacement I drove the car for one tank of gas as a checkout and yesterday I finally declared the engine change out complete and went in to have refrigerant put into the AC system. So here is where this thread begins. The service manager for the Toyota dealership in town is a friend of mine so I had them charge the system which they did and on the drive home the AC started blowing warm air. I took it back and they pulled a vacuum again the recharged it again and did a more thorough checkout and the mechanic is saying that it works fine and then the pressure spikes supper high, I guess its interment . The mechanic says he does not know what the problem is but suspect I have some contamination in the system and it is clogging something up. He says I should try replacing the expansion valve and replace the dryer.

So the first question is about the dryer. It is part of the condenser and I was wondering if because I installed the new condenser and did not charge the system for a month or better did I some how ruin the dryer? Does anybody know how to replace the dryer? Do I need to buy a whole new condenser?

I have been looking into what it takes to change out the expansion valve and the entire dash has to come out. The Toyota dealership told me the book says it's a 7 hour job.

Can anybody offer some advice how I go about methodically figuring out what my issue is? I really don't want to take the dash apart.

Bobster999

Ok are you sure the pressure spikes? are you watching the gauges to see it? or you just know it stops blowing cold intermittently? this is an important distinction. Now after a few days, how is it acting? PM me your number if you want to talk for a minute.

jimsRX300

Intermittent cold air? Compressor cycles on / off? SUPER high (almost 300psi) on the high side? Then it cuts out? I learned, the shut down of the compressor is a safety feature. It's working correctly.

I had a similar issues last year, following my engine swap (I went out the top though). I too replaced my condenser / dryer. My problem I thought was the compressor, well, reed valve. It turned out the expansion valve was broken. It's behind the instrument cluster. There is a temperature sensitive spring on this rod. It was broken. Went to autoblast, fixed. I have the Harbor Freight Manifold Gauges & HF vacuum pump. Did mine myself. Any shop will discharge your system. You can recharge it yourself. Replace all o-rings.

daltongd

So I got it working and will explain what I did

Since the AC would work for a while and then stop I made the determination that the expansion valve was good and maybe the dryer was bad. I thought that maybe some air was still in the system and it was freezing and plugging up the expansion valve.

I ordered a dessication assembly and evacuated the freon and pulled the condenser to replace the desiccant which is part of the dryer. Remember I replaced the condenser so it was a new unit, my assumption was that maybe I left the system open too long after replacing the condenser.

When I opened up the plug and pulled out the dessication it had a little pouch about 2" long if that. The replacement dessication from Denso was about 10 - 11" long. So I installed the new dessication and asked the shop to pull a vacuum for as long as possible (the guy said he would do it 3 hours).

The A/C has been working fine for over a week now so I am going to consider this one done.

Moral of this story is replace desiccant is you open you system right before re-filling and if you buy a new condenser check the desiccant before installing

matts6887

Just wondering; what is a dessication assembly? Is it just part of the dryer party of the a/c system internals that pretty much keep the system running etc?(trying to learn what these terms mean)

daltongd

Desiccant is a material (little rocks) like kitty liter that absorbs moisture. It is in a bag and the bag fits in a tube connected to the side of your condenser. If your standing outside your car looking in, its on the right side of the condenser. The only way to get to it is to take the condenser out of the car which means you have to break into your A/C system.

matts6887

good deal. now i know. Fortunately for me; my a/c system seems to be in pretty good shape. Blows out ice cold air. Which around these parts is a must. I see these goofs all the time around here riding around in cars w/o a/c when its 100+ and it just makes me cringe; and im thinking are these people crazy?