Rechaging AC on '97 K1500

**Indian Truck** · 05-27-2007, 11:43 AM

Hey, Where's the LOW pressure valve on my 97 K1500's AC system. Trying to recharge the AC, bought all the needed goods(I hope), just not sure what valve to tap. By the way, I heard I could DIE doing this(so the Wal-Mart auto guy tells me). Is this true? Thanks everyone........

**ma96782** · 05-27-2007, 02:05 PM

Hey, Where's the LOW pressure valve on my 97 K1500's AC system. Trying to recharge the AC, bought all the needed goods(I hope), just not sure what valve to tap.

My Low pressure fill valve, is located on the Accumulator (yours may differ).

By the way, I heard I could DIE doing this(so the Wal-Mart auto guy tells me). Is this true?

Yes, personal injury or death could result (with most things, an accident could always happen) if you don't KNOW what you're doing.

Aloha, Mark

**Indian Truck** · 05-28-2007, 03:53 PM

Anyone with more details, pics, or more info? By the way, I bought
134a, is this cool? Or do I need R12? Thanks...........

**blue70beetle** · 05-29-2007, 03:30 AM

On my '97 K1500 'burban, the low pressure port is right by the compressor. It's pretty close to the high pressure port, but the hose will only fit the low pressure port with 134a. My '97 is 134a, so I assume yours is too, but if it's R12, the 134a hose won't fit.

**daman1** · 05-29-2007, 04:25 AM

Guy's they havent put R-12 in stuff for a long time now,LOL
everything is 134a, sounds like you ned to do some reading up
on this before you hurt your self or your ac system..

**Z71Nutty** · 05-29-2007, 07:49 AM

134a is the stuff you need...the hose will only go on to one of the connectors. Look for a black screw on cap on top of your compressor. As far as death...well like others said you can die doing just about anything. Heres a pic...

Hey is says "YOU MAY NOT POST ATTACHMENTS"

Sorry man I had a great pic for you too....

**Marcos** · 05-29-2007, 08:21 AM

Also, you didn't have a bad leak or did you do any repairs? That way you evacuate it first...

**SolMan98** · 05-29-2007, 08:29 AM

Originally Posted by Indian Truck

Anyone with more details, pics, or more info? By the way, I bought
134a, is this cool? Or do I need R12? Thanks...........

It's right above the compressor (large black pulley if you didn't know). You will see a black screw off plastic cap. The hose will only connect to that one.

**blue70beetle** · 05-29-2007, 09:27 AM

Originally Posted by daman1

Guys they havent put R-12 in stuff for a long time now,LOL
everything is 134a,

'97 isn't too far from the cutoff...it was sometime in the mid '90s ('94?).

There will be a sticker somewhere under your hood that tells what refrigerant you have. Mine is towards the back on the passenger side, on top of what appears to be the receiver/dryer.

To clarify what I said before, I assume you bought either a can with a hose attached or a can and a hose. In either case, the hose has a quick disconnect fitting at the end, and the only thing it will attach to is the low pressure fitting in a 134a system. That means you can't physically attach it to the high pressure fitting, and if your truck were a few years older and had R12, the hose wouldn't fit either of the fittings.

**ma96782** · 05-29-2007, 04:57 PM

A/C work can get expensive real fast.....tools cost and replacement parts cost.

IMHO....get a book.....it's a cheap investment.....then read it.

Proceed at your own risk. ALL LAWYER TYPE WARNINGS APPLY. Take precautions and wear safety equipment. Release of the refrigerant into the atmosphere is verboten.

DIY...OK....I'M NOT AN EXPERT (so, just assume that I‘m wrong).....get a book.....it's a cheap investment.....then read it.....a Ford is different from a Chevy. Last warning.

Short story.....first is it R12 or 134a (converted or factory)? Factories did the conversion to R-134a about 1994? So, at least you know what you’re dealing with and what type of refrigerant to get.

IMHO…..if you let the expert, dye it, or vacuum it……why not let him do everything to re-charge it?

OK……so, you still want to try? Last warning, again.

Check for leaks.....dye or evacuate (vacuum) the system and see if it will hold a vacuum (30min-60min, your choice). If it's leak free.....continue. IF not....you need to replace parts (don’t forget oil for the components) and/or tighten the connections properly.

If after you replace parts....check for leaks, again......why waste refrigerant?

Say you didn't test for leaks and want to gamble......assuming that the individual components are in good working order? And, you’re still willing to continue.

OK....engine off…….hook up the manifold. Consult the manifold’s manual (directions) on how to use it. Get the initial reading (AKA; Static reading). They'll be a point that the levels will equalize.....note gauges (hi and low side readings). Consult book. The reading will sort of tell you (though, not always)....IF, it just needs a little charge.

Assume here, that it needs a little charge.....ENGINE OFF......with the hoses properly connected and the manifold knobs turned correctly……..introduce the proper refrigerant and let it get sucked up through the low-side port. Can is right side up.

When it's though sucking up, as much as it will take.....note manifold readings. Close off all the manifolds knobs again. Consult the book. Test run.

Still NOT COLD?

Next, turn on the engine, set idle at 1500 RPM, A/C on, A/C fan running.....(a house fan in front of the condenser keeps things cool while the engine is running). Turn manifold knob to introduce more refrigerant into the system via the low-side. (Remember, there are specific capacities involved to properly do the job.) The can may need to be inverted and you mught have to jump the compressor switch (to help it suck up). Keep a watch of the high and low gauges and the temps that you are getting in the interior of the truck.......40 degrees (in F) below the ambient air temps is, "good enough,".......close off the refrigerant and disconnect hoses......It's done. Note the high and low pressures and compare with the book readings. Having an "over charge" is a bad situation too.

Warnings.........there are specific pressure/temps readings involved, and the book mentions that tests are at 80 degrees F ambient air temp. and your location (height above sea level).....so, you're to adjust to the book's table.

ALL LAWYER TYPE WARNINGS APPLY

Here is a good source of info on A/C parts and some other info (note, there is a forum):

http://www.ackits.com/

Aloha, Mark

PS....http://www.explorerforum.com/forums/...d.php?t=158183

From an old thread.

Aloha, Mark

**Indian Truck** · 06-04-2007, 08:31 AM

Hey, I got it, and I'm still alive!!
Thanks a bunch everyone. I'm ridin' cool now.
Not as hard as I thought.

**LoneStarZ71** · 06-04-2007, 09:24 AM

Ok I went to do this today and when I put on the valve hose and turned the truck on with the a/c at full blast the guage hit 100 instantly which reads "Danger". What is going on here? My a/c works fine but it's just not as cold as I know it should. I thought that this would work and do the trick. What could be the problem or am I doing something wrong?