Test for Seized Compressor

AC hasn't worked in a long time. It had been very noisy and then started to grind...

The front end of the Clutch completely chewed itself apart last week. It broke the belt but I luckly had a spare.

There is gas in the system left from when I got it recharged last year. I know this by a gauge on one of those refill cans and by pressing the little pin on the high side shoot pressure out.

I want to just replace the Clutch/Bearings, but I think I need to check and make sure that the compressor isn't seized, right? I can't grab the splines with anything to see if it turns, so I can only use the 8mm Bolt that attaches everything. I twisted that bolt down (without a belt on) hard enough that I just started to feel some the threads round and nothing turned.

This either tells me that ?
1) Compressor is locked up
2) That their is a valve closed
3) Clog in the system, acting like a shut valve
4) ???
Note, i did this test with the engine off and on. Also, pushing the AC button in the car no longer makes the AC light come on. I'm guessing that that is because the Coil inside the Clutch is no longer intact breaking the ciruit.

Thanks for the help.

bigmig said:

I want to just replace the Clutch/Bearings, but I think I need to check and make sure that the compressor isn't seized, right?

Click to expand...

Your compressor is seized, from the description. Do this repair right, or the new one will seize, too. Probably the cheapest option is to replace every part of the system that touches refrigerant. Flushing a compressor death is EXPENSIVE. IF you can find someone willing to touch it with a 10 foot pole.

Oh what a wonderful response...!

I just added up from Advance Auto web site:
Compressor
Condenser
Filter
Evaporator

And I'm at $500 without even hoses...

Is there a way to yank all the components out and do a "flush" cleaning on a workbench? I have time, and I'm know how to spin a ratchet well enough to get it out and back in...

Option 2
Fill the back (explorer) with Rubbermade Bins and keep refilling them with 200 lbs of ice... Drill a hole in the floor for a drain plug...

Yes, it's possible to flush most of this (maybe not the condenser, though). And half that cost is the blown compressor and receiver/drier, which you need anyway.

But do you have the experience to know when you're done?

Another possibility is junkyard equipment. A full-service junkyard with a 609 cert should be able to set you up for much less than that.

Yep. There's ALWAYS another way.....


Remove the expansion tube from the line (grasp, but do not twist, and pull). Inspect expansion tube for debris, then make the big decision based on how much crud is in it.

Remove condensor, evaporator and all lines(*).

Partially fill parts with denatured alcohol (or brake-kleen, carb/choke cleaner, etc >$$$$). Plug ports and rotate and shake component to dislodge debris. Force compressed air through each part to spew out the alcohol through layered cheesecloth. Repeat in both directions. When the cheescloth remains clean, allow part to air dry.

Replace the expansion tube.
Reassemble system (all new seals).
Install the filter dryer LAST. DO NOT UNDER ANY CIRCUMSTANCES RE-USE THE OLD FILTER DRYER. Do not uncap new filter dryer until just before installation, to minimize moisture intrusion.

Apply vaccum. Leak check. Inject oil.
Service with refrigerant.

(You can pay a shop to perform these last four steps for ~$100-150 - SHOP AROUND. You may want to line this up before-hand and ask them about the oil in the new compressor - it figures into the "how much oil to add" equation when servicing. Some techs like to put it ALL in during assembly)

That's about it.

I wouldn't hesitate to do this method, but I've done a few AC's. Once you get it apart and see the degree of contamination (also called Black Death), you can make the decision whether to press on or punt. FWIW, I've found and used JY parts that were pristine (way back when I was young and poor and fixing R-12 AC's in FL for beer and fishing funds).

Figuring a new compressor, expansion tube, filter dryer and servicing....I see no reason you can't get'r done for ~ $500, as long as YOU are doing all the grunt work.






* I'd do everything humanly possible to spew the alcohol through the evaporator and condensor while still installed. If they spew clean alcohol through cheesecloth, BONUS, you saved yourself a lot of work.

Yup, I've heard about the method. But there is a significant element of chance. And if the orifice tube doesn't look really nice, the odds are against it working (after a few hundred on all that stuff).

When my compressor died (under warranty), I ended up spending about $350 on all the other stuff. So, $500 is about what it costs. IF you have your own electrical vacuum pump and you don't screw up.

FYI, "installed" for the evaporator means that the lines are removed but the evaporator is still in the evap box. Removing a condenser doesn't take a whole lot of work. Just barely more than removing the radiator.

Thank you all for the good replies!

I think some day I have off work I'll just start tearing some components out...

$500 is still pretty steep for me... The car has 210,000 miles. And I should be looking into something more economical.

I wonder how much a shop will charge to suck my R134 out? What if I just rigged up a way to leak it out into milk jugs, label it with a sharpie and then just drop it off at a shops door late at night...

I just took a Fluid Power course in college (final is tomorrow), and I liked seeing Ranger44's Post on the inside of his compressor.

Its funny because I had to learn about all kinds of fluid pumps and only saw 2D pictures in a book or on PowerPoint slides... And I didn't know that an AC Compressor was a "Swash Plate" type. (at least I think that what its called, I better study...)
This is cool too!
http://www.youtube.com/watch?v=xt8wiIplRqM
Thanks again.

R-134a at atmospheric pressure is always a gas, so you can't put it in a bottle. It behaves quite a bit like propane. As for how much a shop would charge, you'll have to get on the phone.

Several years ago my dad showed me how to make a "poor man's reclaim unit" out of an old refrigeration compressor and an empty freon tank. All you're doing is sucking fluid and compressing it into a tank, so the concept of building one is fairly simple if you know how the stuff works already.

Aside from the cost of losing the R134a there is no harm in simply letting it go.

It is NOT harmful to the Ozone layer.

Aside from california I doubt there are any regulations REQUIRING that
you recover it.

a Full charge in most Ford systems is two 12oz cans of R134a.
In most auto parts stores on the east coast that means $14.

Last year while I was converting to a 4.0 engine I had to make changes to my A/C system, mostly related to the different line routing and fiffernet compressor

I had a complete 1993 setup that had previously been flushed for a retrofit to R134 (1993's were originally R12) but before I could install that system
I located an Explorer with the Heavy Duty AC system originally made
for "Desert service" (for sale in Nevada/Arizona/NewMexico)

So Installed that instead.

FWIW I have a recovery unit, but it doesn't do anything that
a vacuum pump won't do.
and the unit managed to "lose" ~20lb of R14 over the winter.

BTW, after vacuuming the system and checking for leaks under vacuum
I usually pressure test the system by filling it with propane.
Propane has one great virtue.... it is only ~$0.75/lb instead
of the $10/lb (in 12oz cans) or $3/lb (in 30lb bulk cans) R134a

Theoretically atleast you could fill the system with Propane and it would function

another advantage of propane is that leaks can be found one of three ways.

One is with your ever present Mark1 stench detector, your nose.

The next way is go looking with an open flame.

contrary to what you might think this isn't as dangerous as it sounds, because you'll only get a flame at the leak, it isn't going to explode back up inside the AC system because presumably you pumped it down to a vacuum before adding the propane

so it can only burn after it leaks out and mixes with air.

the third option is with an explosive flammible gas detector. these are
similar in function to a halon gas detector bu tend to be more precise,
more reliable and less easily overwhelmed than a halon/referigerant
gas detector.

The supposedly good halon gas detector I used to have was only slightly
more effective than a polish mine detector.

Once it "detected" it took several minutes of waving it around in
clean air to get it to shut up, so finding a precise location of a
leak was nearly impossible.

Frankly pressurinzing an AC system to 150psi with propane and going looking for the leak with a match worked better.

what worked better yet was going looking for a leak with an ultrasonic sound detector
(intended to find weatherseal gaps) well... atleast until that unit simply died.




AD

Allan, it doesn't make any sense, but the Federal Clean Air Act, section 609 requires recovery of ALL refrigerants.

Propane in a mobile air conditioning system is probably illegal and very dangerous. It's not open flames or flame fronts "backing up" into an air conditioning system. It's collision damage.

section 608 also requires recovery of all refrigerants.nitrogen works well for pressure testing and flushing impurities,not to mention filling tires.

Yes it is illegal to use propane for leak detection in mobile AC, aswell as charging a system with r134a to test for leaks. You can use nitrogen tho as skippy stated. And yes, by law you have to recover all refrigerants and cannot recharge any system that leaks.