Faulty A/C

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

2006 V6 VX- just noticed today that the AC is no longer cold so I suspect it needs regassing. Everything seems to work fine- it just isn't cold. The line from the compreesor is hot but the line from the condensor to the sight window and to the evaporator is barely cool. The compressor clicks in when it is switched on. It is booked in for next week to be checked but my general question is.....how often do they have to be regassed? I hardly ever turn it off so dry seals shouldn't be a problem. Do they slowly lose gas and get to a critical level where the system shuts it down. I can see no evidence of a sudden failure of anything. That said it has not been regassed since new -Dec 05. Neil

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

Since the gas contains the lubricant, if it reaches a certain level then yes it will cease working. Being a 2006 and I'm assuming never regassed then without a doubt its efficiently will be questionable but it will definitely be function unless there is a fault. Low pressure or low gas will result in the compressor switching off.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

The line from the compressor will be hot and the line from the condensor should
be cool that's what the condensor is therefore!

Check the sight glass on the little tank, you will normally see a few bubbles when
the compressor starts and then they should disappear, this indicates the gass charge
is about right.

The system should not leak gass, neither does the gass wear out. You should get many years out of the system without it needing to be touched providing you follow the manufactures instructions and use it on a regular basis to keep the seals oiled. My old KIA is 15 years old now and the aircon still functions perfectly

I suggest you examine the return line to the compressor, if the compressor has been
running for awhile then the return line will normally be cool or cold. Also if the compressor
is cycling on and off it tends to indicate the system is working ok. I know in some systems the
cooling temp into the vehicle is controlled by a flap that controls how much air flows over
the heater core and the evaporator core. If this flap is not operating correctly you won't get
any cooling, not sure how the Prado is setup though. A stuck expansion valve in the evaporator
will also cause loss of cooling and I think from memory this may have been covered at some time
in the forum.

Cheers
Leigh

[rags Advanced Member Find all posts View Profile Close rags]

Replace the relay in the main fuse box under bonnet [approx $25 non genuine] and you may fined that it will be fixed. I went through similar symtoms and after regass no better ,finally replaced the relay and been good ever since. There is a thread somewhere on PP that discusses similar issues

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

I have a suspicion that there is a miniscule hole in the front of the condensor, possibly caused by a stone through the grille or a whack from a wayward spanner. There is a tiny mark and a tiny bit of missing paint. I can't see a hole there but a few months ago I noticed a symetrical pattern of a fine oily substances around this same spot. i cleaned it off and it has not reappeared but if gas escaped here under pressure it may have been down enough not to reappear. This raises the question........ could such a small hole [ if indeed this is the problem] be soldered up to save replacing the hole condensor which I assume will cost an arm and a leg. Neil

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

sometimes it's a good idea to replace the condensor at the same time as a recharge.

I do it from time to time. Our MY97 Prado is on it's third condensor.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

The compressor won't normally run if there's no gass in the system, from your
description doesn't sound good though the tubewould be quite thick. I think it
would be very difficult to solder the tube due to the oil inside the condensor
etc, the repairer would proberly and wisely push a new condensor.

Cheers
Leigh

[johna Member Find all posts View Profile Close johna]

The discharge line from compressor should be too hot to touch, the liquid line return from condenser coil should be cool, and the suction line from evapourator back to the compressor should be very cold. There was a problem previously where the temperature sensor was too close to the evap coil and cycling the compressor off too quickly. The fix may still be on the forum. I just had a problem with my 2003 not working, and after a few hours checking clutch and wiring, finally located an intermittent relay problem in the main fuse box. $127-00 from Toyota and $15-00 from an auto elec shop. The difference appears to be that the genuine relay is electronic and the cheap version is the old relay / contact type. Made sure it all worked normally, then belted the Toyota intermittent relay on the concrete a few times and re-installed and it is still working normally. Put the spare new relay in a blank socket in fuse box in case it is needed later on The fog light relay is identical to the A/C relay, so you can use it an emergency as well. Note: Testing an intermittent voltage from a solid state relay can give some false results, i.e. it fooled me for some time as I was getting 13 volts at the clutch and another check gave bugger all or a lower voltage which makes it hard to identify as to where the voltage drop originated from. OK if you are a Toyota mechanic and just keep swapping parts until fault found, but very bloody costly for the customer. The 2003 GXL has done 200,000 klms and has never needed re-gassing and should not need it if gas is not leaking. The law does not allow for a topping up of refrigerant, you must decanter the system, pressurise it and find the leak, fix it, then evacuate the system prior to adding the correct gas charge.

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

Update: It was a miniscule hole in the front of the condensor- showed up when they gassed it it and put dye in it. New codensor.... not sure yet whether it was a Toyota one or after- market one which was $150 cheaper- depends on which one showed up first. BUT, and this may be of interest to all of those with older 120s. Mine is late 2005. When he pulled out the radiator to have a look at it , not only did it have a lot of dust in it even tho it has been thoroughly cleaned after any trip involving dirt but it was disintegrating! The aluminium was fretting and simply falling apart. It was not leaking or blocked but was certainly headed for failure, no doubt at the most incovenient time!It will be replaced tomorrow by an aftermarket unit which is of higher quality and lower price. While it is all out I am having the original hoses and serpantine belt replaced. Have a good look at your radiator if it is a few years old. I will report costs when I pick it up tomorrow. Neil

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

Take an oxygen mask with you when you get the bill lol

Glad it's all sorted and teh radiator was caught before failure.

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

By the way, my mechanic said that this was the 4th Prado radiator that he has done in the last 3 months- all with the same problems so it is an issue of age in the older ones - definitely worth checking. Neil [with oxygen at the ready!]

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

Well, much better than I expected. All repaired using aftermarket parts- New radiator-$230 !!!!! dirt cheap; new condensor $340, compared to $600+ for genuine. New serpentine belt and new hoses [ supplied from my spares], regassing of AC and labour. All came to just on $1000. The corrosion on the radiator, by the way, was where the tubes connected to the bottom tank and was close to eating through the tank. Lots of fretting at the bottom of the radiator where it is hard to spot. He said he is seeing a lot of it in aluminium radiators round the 6year old mark. If yours is around that age check before the next trip- at $230 ish for an aftermarket radiator it is cheap insurance. All this after a slipping spanner [no names] clipped the front of the condensor while tightening up the bull bar bolts. Neil

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

Hey I guess thats not so bad after all eh? Glad it worked out well in the end.

[K & M McF Senior Member Find all posts View Profile Close K & M McF]

My 90 series lost gas from A/C. Problem was the condensor pipe flexed over 10 years enough that it ended up rubbing against the radiator (I think) and wearing a tiny hole.