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Vehicle AC tech in Chit Chat cause I know nothin

dntsdad

Central California
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May 19, 2020
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92 Toyota pickup with 3.4 swap in so a 154 compressor that came on the 3.4 and the rest of the system is r12

The system was never charged cause I couldn't figure out the wiring when I did the swap wiring. I think I have a plan now for the wiring to make it work with the ECM and how it should.

I don't really want to take it to a shop to charge it cause of all the variables and "custom" shit going on with the vehicle.

Can I just to Napa and but those cans and dump them in? I know I will have to manually jump the compressor to get it to start pulling for a while but not sure how long, or how much I should say, before I can just let the switches take over and allow the system to take over.

and I can just use the shitty gauge on the can to read full?

Or do I HAVE to vacuum to whole system and all that?
 
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You must vacuum the system and make sure it will hold that vacuum for thirty minutes. Install a new drier. Buy gauges.
 
Maybe you mean evacuate the system ?




You must vacuum the system and make sure it will hold that vacuum for thirty minutes. Install a new drier. Buy gauges.
 
System has no gas in now and hasn't for years.

I will change the drier. I forgot to mention that.

Another thing...is it true that the R134 will eat up the seals in the fittings and connections? I thought that I read a long time ago that all the seals would need to be swapped out?

True or old wife's tale?
 
No matter how long the ____ has sat the system still (from my education in AC school) has to be eva uated or it wont suck in the freon.

The system isnt being pressurized as I understand it is sucking in the freon, somewhat like the tube your blood goes into when you have bloodwork done.

https://itstillruns.com/evacuate-auto-ac-8130915.html

System has no gas in now and hasn't for years.

I will change the drier. I forgot to mention that.

Another thing...is it true that the R134 will eat up the seals in the fittings and connections? I thought that I read a long time ago that all the seals would need to be swapped out?

True or old wife's tale?
 
1. But a set of gauges, they're invaluable.

2. You pull a vacuum to check for leaks and remove any air/moisture. Which could cause acid and that would wreak havoc.

3. I would purchase the condenser/drier/expansion valve for a 95 4runner for a "bolt in", complete, efficient R134A system.

4. You shouldn't need to jump the compressor to make it kick on after adding freon.

5. Walmart cans are 4.88 each and work fine
 
My neighbor has a vacuum and gauges! So I have those now.

That is a good idea on the 95 Runner parts. When was the switch from r12 to 134?
 
OK. I thought so. I can probably buy a kit that is put together for a 95 Runner and swap all the orings and compressor seals out.

R134 ones should be green right?
 
Don’t fuck around with compressor seals until you check the system for vacuum leaks and you know that the compressor is good. If it were mine I would replace the shaft seal and the head gaskets on the compressor first.
 
Maybe you mean evacuate the system ?

No, he means pull a vacuum on it for 15-30 minutes to boil all the moisture out of the system.
 
dmg
What does evacuate mean?
The rest of you... Good lord proofread much?
 
dmg
What does evacuate mean?
The rest of you... Good lord proofread much?

See definition 2.2

e·vac·u·ate
/iˈvakyəˌwāt/
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verb
  1. 1.
    remove (someone) from a place of danger to a safer place.
    "several families were evacuated from their homes"
    Similar:
    remove
    clear
    move out
    shift
    take away
    turn out
    expel
    evict
    ask/force people to leave
    make people leave
    make people get out
    empty
    depopulate
    unpeople
  2. 2.
    TECHNICAL
    remove air, water, or other contents from (a container).
    "when it springs a leak, evacuate the pond"
 
Aren't you supposed to check for leaks by pressurizing the system with something clean (like argon from a bottle) so that if there is a leak it will leak out and not pull junk into the system?
 
I actually watched some YouTube videos last night on this and it looks pretty simple.

I should have done that first! :homer:
 
Aren't you supposed to check for leaks by pressurizing the system with something clean (like argon from a bottle) so that if there is a leak it will leak out and not pull junk into the system?

From what I saw you just pull a vacuum with the pump and then close up the gauges and see if the vacuum holds for an hour or so.
 
So what components is the system would I want to change out if I am going to convert to R134? As was mentioned above, I will just get part for a 95 Runner other than the compressor since that is mated to the 98 3.4 so that is already done

Seals and compressor for sure.

I need to change the drier and accumulator anyways so those as well.

What about the expansion valve? Should I change that to an R134 or does it matter?

I assuming that the condensor and the evaporator core would be OK to leave from the R12 setup?
 
Aren't you supposed to check for leaks by pressurizing the system with something clean (like argon from a bottle) so that if there is a leak it will leak out and not pull junk into the system?

This is correct. Nitrogen is best because it is dryer and cheap, but I use argon because I have it around. If you leak check with vacuum there are several problems. First one is how do you know where it leaks? (You can use glass cleaner with pressure and watch for bubbles) Second, you can only vacuum to a small psi differnce. With pressure you can simulate running conditions. Third, as mentioned, if you have a leak, it will suck shit in.
 
So what components is the system would I want to change out if I am going to convert to R134? As was mentioned above, I will just get part for a 95 Runner other than the compressor since that is mated to the 98 3.4 so that is already done

Seals and compressor for sure.

I need to change the drier and accumulator anyways so those as well.

What about the expansion valve? Should I change that to an R134 or does it matter?

I assuming that the condensor and the evaporator core would be OK to leave from the R12 setup?

I would guess that you don't have an expansion valve. It will probably be an orface and I would change that. When you pull the orface, inspect it for gunk. If it has a lot of gunk on it, you need to blow out your condenser. The evaporator should be good.
 
Maybe you mean evacuate the system ?

your fucking special arnt you?

Evacuating is removing the refrigerant, Vacing is literally putting a vacuum on the system to ensure there are no leaks and drawing out moisture. You dont really need it to charge as you can charge it on the low side as a liquid vs doing it via of vacuum on the high side as a gas.

I personally would run a vaccum on it for like 30 mins. YOur looking to see 29 inches of HG. If you never get to that..you have a leak. When you get to the end of the 30 mins you need to let it set under a vaccuum but the pump not running for 5-15 mins and monitor your gauges. You guages should not, in this case, gain pressure.
 
Aren't you supposed to check for leaks by pressurizing the system with something clean (like argon from a bottle) so that if there is a leak it will leak out and not pull junk into the system?

You do that to find the leak it self. placing a vacuum on the sytem will tell you that there is a leak in the system and using a inert gas argon/n1 what ever will give you a pressure to find using a soap and water.

You can also pressurize the system with a inert gas and inject dye into the system and using a uv flash light to find the dye.

you can use a sniffer once the system is full to detect leaking refrigerant but i they false positive alot and they suck, really only good IMO of sticking the probe in a evap box to see if a evap is leaking.

You can mix dye with our oil during charging to catch a leak that a sniffer and argon wont find. Its also another way to find a evap leak (your condensate line will glow)
 
Yes but dont go off topic, the only reason I said that was when someone goes into get service and they use the wrong terminology they generally get taken advantage of.

Just didnt think the OP wanted this.


your fucking special arnt you?

Evacuating is removing the refrigerant, Vacing is literally putting a vacuum on the system to ensure there are no leaks and drawing out moisture. You dont really need it to charge as you can charge it on the low side as a liquid vs doing it via of vacuum on the high side as a gas.

I personally would run a vaccum on it for like 30 mins. YOur looking to see 29 inches of HG. If you never get to that..you have a leak. When you get to the end of the 30 mins you need to let it set under a vaccuum but the pump not running for 5-15 mins and monitor your gauges. You guages should not, in this case, gain pressure.
 
I think that if I pull vacuum and it ends up having a leak, I would just use a sacrificial bottle of 134 with dye, run it through with one of those little gauges that come with the bottle, and look for leaks that way and then fix them and refill for realzies.

I don't have a torch so no argon and a small bottle of the 134 with dye is only a few bucks

??
 
Not everyone wrenches for a living, so evacuation can mean both depending on who you're talking to. In science and engineering evacuating means pulling vacuum.

Anyway pulling vacuum on a system that has been open or has brand new components for as long as possible will draw off moisture and other volatiles, which is good for the system as a whole. Losing vacuum is probably a leak but it could also be due to trapped moisture. If you pull vacuum longer and the leak slows down, it's probably moisture. Another way to check for that is to pull off the vacuum pump and apply a heat gun or hair dryer to some of the lines, if there's moisture the extra heat will speed up the vacuum loss. Sometimes if you do that while pulling vacuum you can even hear the pump gurgle a bit when the extra vapor gets pulled out.

The moral of the story is to use as big a pump as you can get and let it pull for as long as you can. I use an Edwards E2M5 2 stage vane pump rated for damn near absolute vacuum (it was a castoff from a decommissioned mass spectrometer) and that heavy bitch works so much better than the auto parts store or harbor freight units.

his next post said he went to AC school.
 
I think that if I pull vacuum and it ends up having a leak, I would just use a sacrificial bottle of 134 with dye, run it through with one of those little gauges that come with the bottle, and look for leaks that way and then fix them and refill for realzies.

I don't have a torch so no argon and a small bottle of the 134 with dye is only a few bucks

??

Legally no

But ive done it

The uv flash light is only a couple bucks aswell.
The dye is vibrant, alien jizz.

The flash light just makes it way more noticeable.

On your expansion valve question. Apparently you do have one..im suprised. 134 or 12 its not going to matter it just meters the flow of refrig into the evap actively and variably. Where as a orfice tube is basically a refrigerent jet (like a carb jet)

Its not super easy to get to to but you could clean it out with ac flush. But if you flush the whole system youll get it that way to.

You could check operation with a ice bath and a blow dryer. Its a spring loaded assembly with a thermo-bulb with mercury? in it and it open or closes the valve based on a tempature, in reality it never closes nor does it it open the valve it just adjusts the flow.


Here is a pdf of expansion valve area. My dumbass cant get it to convert from a pdf to a jpeg
 

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To do it right, you will need to spend some money on decent gauges, a vacuum pump, and the refrigerant. If its a one time thing, pay someone off CL to do it.
 
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