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Checking for leak on truck ac

rkevins

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Aug 6, 2011
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Central Arkansas
My 93 ranger has a bad leak in the ac, I had someone check it he ran a vac on it and it did'nt hold long. It worked for a while last summer so I am hopeing I blew a oring or something simple.
My question is before I spend a lot can I use compressed air to leak check using soap and water.
I know compressed air is Not the best thing, but will I ruin something doing it.
Or what would be better mabie a can of r134a?
It was upgraded to r134a but I don't know what all was done when it was done, It was done for mu uncle and we got the truck after he passed away.
 
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Brian_B_

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May 12, 2012
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North Central, AR
I am not an AC guy. Not at all. My old ranger was converted..it worked for 2 or so summers then quit. I was told the r134a damages something in the old system after enough time. A shop wanted a fortune to repair it that time.

I ran without AC for several years and my brother drove it for a couple after that.
 

38Chevy454

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Dec 26, 2006
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Cincinnati, OH
Well, assuming that you will have to break it open to fix the leak, it will be exposed to air then. Problem with using air is that it may be hard to find with soap solution if not enough of a leak. Or accessible to see bubbles. I say you have not much to lose, so try it. Sniffer is more sensitive.

Basic low cost conversion, assuming no failed parts, would have hopefully been flush out old mineral oil, fill with new POE (aka "ester") oil, pull vacuum and recharge with R-134a. If done right this should have worked.

If you do need to replace some O-rings, make sure to put lube so they do not tear or rip when installing. Probably not a bad idea to flush the system if you have it opened up, and recharge with POE oil. Pull good vacuum and see if it holds. If not you still have leaks obviously. If holds vacuum, then charge it up and enjoy working A/C.
 

cgall

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Jun 6, 2012
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Cincinnati, OH
Get a couple of cans of R-134a with dye and a $10 hose at the auto store and charge it back up. When it dies off again, look for the yellow dye around all of the hose connections. A blacklight bulb will help, if available. If no dye can be found, it most likely is leaking at the condenser under your dash. You can then make the call to spend two days ripping out your dash or paying an auto shop $1800 to do it.
 

jaredlucky16

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Nov 6, 2011
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Blowing air into it will prolly ruin the dessicant bag in the dryer. I would go the dye method if i were you
 

Carguy99

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May 25, 2012
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Warrenville IL
DO NOT USE AIR!!!!
Compressed air mixed with R-134a froms a combustible vapor.
The vapor can burn or explode causing serious injury.
Never use compressed air to pressure test R-134a service equipment or vehicle air conditioning system.

I suggest dye and a simple recharge
 
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lsrx101

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Jan 28, 2008
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Brownhelm Station, Ohio
There are 4 very common leak points that I've seen on 90s Rangers:
-Discharge hose where it loops around the power steering filler neck. (4-cyl) This requires replacement of the manifold and hose assembly.
-Compressor shaft seal.
-Compressor body seals.
-Discharge hose to condenser connection. You will usually see oily dirt buildup on the connection.

This is obviously not the only places it can leak, but are the prime suspects for that particular vehicle.
Since the vehicle is pushing 20 years old, spend $12 and replace all of the o-rings in all of the connections along with the orifice tube. Very cheap insurance.
As mentioned, flushing should also be done since you don't know how the "conversion" was done previously or how much/how many types of oil are in the system.
At this point, you really need to replace the 20yo accumulator regardless of the rest of the repair.
 
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Milton Shaw

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Feb 11, 2011
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Another area of leak is loose hoses on fittings. The crimp deforms the hose and then the hose will turn on the fitting. When the engine torques and moves on the mounts the hoses will move on the fittings and leak. I have seen many GM cars with leaking hoses that the crimp is now loose. Requires recrimping the aluminum piece or replacing it with a clamp (not just a screw hose clamp.).
 

Tarheelgarage

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Dec 14, 2008
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NC
I believe tha Ranger used the FX15 ac compressor; it was known for being a marginal candidate for R134a retrofits and would **** the nest often. Remans were not much better.

Check closely on High side (vapor and liquid) lines as those are the areas that take the brunt of the AC process. Also have seen condensors with leaks at lower edges.

Replaced Accumulator as you have ruined it with compressored air and moisture.

I use dry nitrogen when checking for any leaks after repairs....:thumbup:
 
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