hey guys, just thought i would share with you a lesson i learned today
My aircon developed a massive leak (has been about 4 years since conversion to R134 gas) and at first i thought it was the TX valve, replaced that and still leaking. Ran some dye through it, regassed it and yep, lasted a week then stopped working. (Luckily i know a good aircon bloke and i get my gas for free)
It turns out my front o ring on my compressor is shot. This is apparently due to the fact the R134 runs under extreme pressure compared to the R12?? that it was designed for initally. Im looking at about 700 bucks (trade) for a new compressor, but we are hopefully going to find the source of a kit for around the 50 Dollar mark which will allow us to rebuild my compressor. Thats not a definate available thing but we'll see we go.
Rang my uncle up who is a Service manager at Ford and he knows this problem too well. To combat the problem, he recommends i install a 10inch thermo fan RIGHT IN FRONT of the evaporator, and wiring it to switch on whenever the Aircon is switched on. I have managed to secure myself a brand new repco brand (built by Davies, Craig) for 85 dollars (again, trade) and in the coming weeks will begin the install. At the same time I will also probably give the clutch fan the heave-ho and throw in another 10inch to control normal cooling (is that really a good price? 85 bucks for a 10inch thermo).
So if any of you have the conversion done recently and are wondering why its not working, dont overlook the compressor. The TX valve and its associated O rings are always your first place to look, but if you are unsure, take it to your air con bloke for the magic dye/black light test.
Instead of 2x 10" fans, why dont you run an EF/EL dual fan setup.
I have a 10" and 12" elect fan on mine, and found that if the fans did not come on with the a/c, and the car was stationary, the compressor would actually lock up and squeal the clutch, because the condenser was getting that hot, that the compressor could not pump any more pressure into the aircon circuit.
even with the 10 and 12" fans on a hot day, it will still run 1/2 to 3/4 on the gauge.
Also with the fans, dont make my mistage - make sure you use heavy duty relays (40/50A) and 30 - 40 amp wire, and do NOT use fuses, use circuit breakers instead, as the fans can surge upto 40 amps on start up, and draw a continuous 20amps (for 2 fans) which leads to a lot of heat within fuses and small cables
I have built a circuit (based on a jaycar kit) that piggy backs off the temp gauge, which turns the fans on at a preset temp. and back off when it falls below that temp and a bit more.
use this in conjunction with a diode from the a/c compressor, and you should be right. I've had this setup for around 2 years and never had a problem. if you want more info, email me.
Hey garth, When i got my car, the A/C was rooted anyhow so when i went to get it fixed, they ran the dye thru it and found the compressor seals too be leaking anyhow... they replaced them and did the conversion and so far (over a year) its been fine.
Excuse my arrogance but what would puting a fan on the evaporator do?? do u mean condensor??
One thing however that annoys me in my car is that whenever i go over a small bump, my blower fan seems to get stuck or makes a loud vibrating sound untill i turn it off and on again... anyone got idea's on this?
EB1 3.9L MPI Falcon Wagon with converted T5 / Pacemaker & 2.5" Redback sports exhaust / 2" lowered blocks at the rear, Kings lows up front / ED Tickford Head and Cam / K&N panel filter with XH intake Snorkel / Full EL Fairmont interior with woodgrain
89 EA1 3.9L TBI Falcon Sedan with 3 speed auto / currently being upgraded...
Personally, if i was you, id put a 10" in front of the condensor, and a 12" in place of the std fan (to the left), on a hot day, it will get slightly warm. 2x10's might be insufficient. - If you want pics of my setup, let me know and i'll email them to you.
Also, when you do put the fans on, go to your hardware and get some of that adhesive foam stuff they use to seal doors etc, (its about 10mm wide and around 6-8mm thick, with adhesive on one side) and when you take the radiator out, put this around all 4 sides of the core, about one inch in from the sides, and also run one length down the middle - so you are basically putting a window frame around the radiator core, so that when you put the radiator back in, the foam mates up with the condensor, therefore all air flow from the fans is forced through the radiator, and not around it.
Also dont forget to reverse the blade and polarity of the inner fan, as it will be sucking air instead of blowing air...
Yea i work at Bunnings so I know the stuff you are on about. I think i will go 12inch, how hot usually will it get on a hot day? I think i will invest in a temp guage anyway, something with some degree values.
Yea i wont forget to reverse polarity :) Should i keep the old shroud on it though? We werent planning on fuses, circuit breakers will be the go.
oh yea, what Jaycar kit did you use and what mods does it need? My old mans an avionics engineer and im doing a traineeship to become the same, so my electrical skills arent too bad. But still, why invent when someone else has an already sound system :)
Well I fitted a 12" electric fan to the front of the condensor when I first got my NB wired to switch on with the air con compressor (to keep the car cool on hot days turned out to be casting sand in the radiator) but I have still had various 'O' rings go be fore and after converting to the new gas. So I not sure how much of cure this will be.
Aussieblue you say you kept having o rings blow are they your compressor o rings or the ones on the TX Valve? im trying to prevent the o rings on the compressor from blowing, the others are a half an hour fix anyway so its no real drama
Does anyone actually know if I can rebuild my existing compressor? or am I up for a new one?
I didn't say the same ones kept blowing but I have had the ones at the TX valve, the dryer and the front couplings go in turn although all new 'O' rings were fitted at the time of conversion. The compressor failed prior to the conversion and initiated the conversion and the fitting of an uprated compressor. In theory Sanden ones can be rebuilt with this gear http://www.ctd4ac.com/22260.html and the manual here http://www.sanden.com/support/pdf/sd7servicemanual.pdf. Getting the parts is the hard part.
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