AC charging questions.
 

What are the 3 hoses here for and which one is plugged into the larger compressor outlet line going to the condensor? What are the other 2 lines for?

Also I was going to use vacuum from the brake booster line to evacuate the AC system first, but to do that I need something to hook btwn the booster line and the AC system with a gauge so when I shut the valve btwn the booster line and AC system the vacuum is held and I can monitor the vacuum level.

Will this thing do it and if so how?

http://cgi.ebay.com/ebaymotors/Auto-...spagenameZWDVW

Why do you feel the need to do an evac ?



:)
Fred

One line should monitor the high pressure side and one line for the low pressure side. Not sure what the 3rd is for unless it's the freon pressure going in from your source?

Yeah I'd want to pull a good vac on the system first too.

The 3rd is the freon source.
What's the sight glass showing when you have the A/C on high ?

If it's just leaked a little there's no reason to evac it all and recharge it.
Beside's, without a way to recover the evac'd freon (like with an A/C machine), you're just dumping freon into the air, which is not a good thing.




Fred

I think he's done an engine swap and had the system open for a while.

Ah, that throws a whole new light on everything then ;)


It that's the case then evac we must and remember that you MUST change the dryer.




:)
Fred

We can't explain an entire refrig course in one paragraph. Take it to the pros, you'll get yourself hurt.:fire:

Yeah I put a new dry/receiver on mine too. The FSM probably covers this process.

Thanks for the replies so far guys! :)

Will that manifold and guages allow me to evac the system like I was thinking? If not, you guys have any suggestions?

The system has no freon in it left anymore, the compressor grenaded and the evaporator is a leaker too. Im sourcing a used compressor, evaporator, and condenser, but am definately getting a new drier as yall suggested! :D Do you think the expansion valve is shot as well and should be swapped? The system has not been used and open to air for the better part of a year now.

Mt Goat - not doing an engine swap but rather a top end rebuild on my 3vze, but yes same conditions. :)

Bruizer - actually I tried that route about 8 months ago. Took it in to our family's AC shop, the guy is GOOD with all our domestics!! However the guy quoted me 1500 to replace the compressor evap, and drier, evac, r134 conversion, and charging. Sorry but thats worth more than my truck blue books for. Its time I learn anyhow, since the concept and system appears rediculously simple, particularly with my toyota FSM, they just dont give me details about the actual AC manifold and gauges.

Yes, if the compressor truely "grenaded" then you MUST replace the expansion valve/orifice tube also.
You'll have to do a R134A conversion at the same time as it's highly unlike you'll find R12 at anywhere close to a reasonable price.
This means that you'll have to change the service fittings also and flush the snot out of the system. The oils in R12 and NOT compatable with those in R134A.
A used compressor is a scary proposition, but if that's all you can afford, then there you have it.
Make sure to flush the compressor really, really good also.
Since the system's now cleaned out and you're changing most of the components, you can't simply recharge it with freon, you'll have to add oil to the system also else you'll burn the compressor up in a heart beat.



Best,
Fred

I've heard as long as you put in an ester oil you'll be fine. I have a bottle of it that a friend (Toyota tech at the dealership) gave me. It's Castrol Retro A/C, its a polyol ester lube designed for R-12 or R-134a systems. It is stable to residual R-12 left in the system.

I found tons of R12a on ebay for not a whole lot it seemed. (well significantly more than R134 at walmart...lol), I think ima go that route with boot leg R12...lol

Now some of the R12A is advertised with "leak finder"....what is this, some sort of red dye in the R12a that allows one to see where its leaking from?

I found some "Freeze 12" on an Ebay store, run by a dude in WI, kit came with some lube, leak stuff, and 3 cans, and you can get converting valves too. less than 100 bucks and I'm cold. :-) Not perfect, but close enuff.

To evac your sytem, you need a vacum pump. Couple hundred alone for one.

The red hose is high pressure, the yellow hose is low pressure and the blue is for your freon source.

The sight glass is to see if your putting gas or liquid into your system. Put the wrong stuff on eht wrong side and you will slug your compressor. BAAAAAD juju there.

If you have never done it before, find someone who has to do it with you or find a shop to get it done.

Did them quite a bit some 18 years ago and sold all of my equipment. With the convertion to R134 and the certificates going into doing this stuff, it isn't worth messing with.

If your compressor came apart, you need a new dryer, o-tube and I would even suggest a total system flush. Nothing like getting it all back together and then have to pull it down again for crud in the condenser.

O tube what's that?

Orifice tube.
I'm not sure if yours has an expansion valve or an o-tube.

Regardless you need to really, really flush the system good.




Fred

What does one normally flush with?

Wow, so there is a little filter in there huh, where is it at on a Toyota truck?

The link is more to explain what the expansion valve or o-tube does more than anything else.

If the compressor fails, your choice not to flush the system or replace those components where the crud collects.

Either way, it's your money

ok we definately have an expansion valve not an orfice tube. The Expansion valve is found in the evaporator.

God I love my toyota FSM!! :D

So what do I flush with? Coolant?

Also how much compressor oil should I put in the used compressor?

good link and good read.

question - when they flush the system fully, and its all completed, the system cant be exposed to atmosphere right? Or does it matter since the next step is evacuation?

Sorry for all the questions...

Ok im not thinking clearly here...uggg You guys with experience is this a wise course of action? Money very limited right now...


The last time my truck was in, my evap and compressor and clutch were shot. As a good rule of thumb, per my AC dude and you guys, accumulator and expansion valve should be replaced with new.

Im buying a guy's fully operational AC system from here to swap out the evap and compressor.

After installing those (how do I add the oil?) Im taking it to the AC guy and have him flush, evap, convert, and charge with r134.

Parts cost will be about 90 bux and then whatever the AC guy charges me....

I realize that the used parts (compressor and evap) are goign to be the weak links but I just cant afford new...or even remanufactured units. Is this a wise course of action or should I just grin and bear it for a few months saving up $$

He will (should) put the oil in with the freon. Make sure you tell him when you bring it in it has no oil in it.

Even if you replace the major components (after a compressor failure) you still must flush the lines, etc. They'll be crap in 'em.




Fred

But how do you know if the oil is out or not? Like on mine, I did a compressor swap with my engine swap and had the R-12 recovered by the dealer in my original system before I started removing the engine. Do you think they recovered most of the oil too?

If it was flushed then all the oil would have been removed.
Evec'ing the system and flushing it is not the same thing.
Flushing is done after the evac., assuming that the system was closed to begin with, thus requiring the evac.



:)
Fred

It wasn't flushed, just the evac. So is most of the oil is still in there? That one link posted said Toyota doesn't recommend flushing. I kept my system as clean as possible by plugging up all the opennings with rubber stoppers and wrapping with tape while the hoses were disconnected.

Some percentage of the oil is/was still in there. Don't know if there was oil in the used compressor that you swapped in or not.
Did you replace the dryer ?
That really should be replaced if the system is opened for any time as it contains a dessicant to dry the freon and exposing it to air, especially if you're live where it's the least bit humid will generally overload the dessicant in the dryer.




Fred

Yeah I replaced the dryer already. The compressor was from my 2001 Taco donor truck and the system was working fine before I cracked it open, it has R134 of course. It should have all the oil in it, because I didn't have the R134 recovered (I know :chair: bad boy)

Oh, it sounds like that everything should basically be ok..



:)
Fred

I found this write-up today: http://www.asashop.org/autoinc/march2003/mech.cfm

Do our compressors hold oil?