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Bear with me here....
Getting towards the end of my 87 4Runner Restoration. This past weekend I attempted to charge the AC at my dads shop. Didn't work out as planned.
The AC system passed the leak test just fine but the AC wasn't cooling....the best we could get out of the vents was 62 degrees, barely cooler than the ambient outdoor temp.
We put 1.5lbs of r134A in there since the FSM says 1.3-1.7lbs. Since it wasn't cooling we experimented with 1.0-2.0lbs of freon....no improvements.
Anyways, the low pressure side was reading between 31psi (too little freon) to 40psi (too much). It was in the upper 30's with the correct amount of freon. The FSM says 21-28psi of pressure is normal.
I don't recall the exact high side pressure but it was well above what the FSM says.
My old man thinks its the condenser even though it looks pretty good from the outside. He said the condenser is probably rough on the inside and is acting as an obstruction.....causing the high pressures and poor cooling.
Now the million dollar question... It looks like I have two condensers. The normal large one and a small one directly in front of the large on. The small one is about 4 inches tall and is as wide as the main condenser.
When we called the local parts places they just reference the main one. toyotapartsoverstock just shows one condenser on their diagrams. Do I just take the smaller one off?
The best price on a condenser locally is $145 for a Denso. OEM goes for about $225.
I searched google images and came up with someone's picture of an identical set up. I highlighted the secondary condenser in blue. So I guess I am asking.....does it sound like a condenser? And what the heck is up with the secondary one? Was that some special option? I can't seem to find an OEM diagram that shows it!
Last edited by AdmiralYoda; 06-02-2014 at 05:03 AM.
Before you change one of the most expensive parts have you changed your expansion valve? They rust out badly and stick on these things. I know it means dumping the system and recharging again, but in reality you should change your dryer and expansion valve if you change the condenser anyway. The valve and dryer are cheap ($40 for both parts) and I would consider doing at least the valve first before spending hundreds on the condenser. Just my 2 cents. Sorry not to be much help with the condenser, mine is different so I don't know.
God I hope it isn't the expansion valve. We rebuilt the entire heater box with a new heater core and evaporator when we had the interior apart. I just put the entire dash and interior back in!
Since the entire 4Runner is basically built around the heater box assembly I think I would drive around without AC before I would take it all apart for a $15 part!!!
For what its worth I did order a new expansion valve when we were rebuilding it but the wrong one came. The old one looked to be in good physical shape so we had another beer and put it back together.
Geez I hope it isn't that. Someone else chime in and give me some good news please.
You're using R134a in an R12 system, so your high side pressures will be higher than FSM spec, and it should only be charged to around 80% of the R12 capacity listed in the FSM. R134a needs a larger condenser to be as effective as R12, but it will still cool. I converted my 92 to R134a a few years ago after fixing a leaking O-ring and it worked well enough to keep me cool without a new condenser. With the engine running about 1500 RPM and AC on I filled it until the AC compressor was cycling on for roughly 5 seconds and off for 4 or 5 seconds. I also recorded how much I put in and it came in around the 80% mark.
Where do the lines go coming off the part you circled?? Are they tied into the AC System?? No telling what kind of things people add. Aux transmission cooler??
Its definitely OEM as I've seen the identical setup in more than one picture.
The OEM line goes to the large (normal) condenser. The output of the normal condenser goes to the secondary condenser. The output of the secondary condenser then goes to the drier.
I may play around with a few more things before I start replacing parts. The idle up switch for the AC isn't working so we just clamped the throttle to stay at 950RPM. I will go a little higher with it and see if it makes a difference.
I will also check to see if the factory foam spacers are between the radiator and the condenser....I replaced the radiator recently and I don't remember seeing them.
I'll also add some more freon back in as I think we took too much out. When we looked at the sight glass on top of the drier the freon was starting to become gaseous.
Last but not least I will take a look at my compressor. It was late in the day at that point but I don't think it was cycling. I think it was on 100% of the time.
Yes, that little condenser in font of the main condenser is factory!
That extra condenser in front of the main condenser is a factory setup on the first generation 4Runners.
Since the 4Runner has much more space to cool than the cab of a pickup, Toyota added more cooling capacity to the condenser by adding this extra condenser in front of the main condenser.
You can still buy a new (OEM) Denso unit (they come as a complete assembly). It should be just fine to use this condenser on a pickup too.
06-02-2014, 04:59 AM
