Roen

iTrader: (2)

BAC Valve?

Roen

iTrader: (2)

Actually, I was thinking, could it be a clogged or some otherwise faulty expansion valves that could cause condensation to form and spill out through the sides of the evaporator box? My logicon's relay is broken, so only max fan, and thus, max A/C works. Would that be a problem factor as well?

DJMOJO

iTrader: (1)

For the summer months!

First let me just say this thread should really be a sticky or at least put in the FAQs thread icemark made.

Ok so I’m a personal friend of Jerrat/J-rat/Spacerat (guy who started this thread) Tucson has gotten hotter than all hell in the past month, my compressor broke last august and I didn’t get a chance to fix it/charge it till now. I picked up 3 cans of freeze 12 and I had the system evacuated this morning for about 20 minutes (no leaks). I brought the car home and put a can and a half of freeze 12 in. The ac was blowing cool when the car was on at regular idle speeds. At one point I thought I put too much in because the pressure was at like 65 so I stopped at that turned the car off and cooled off in my house.

An hour later I walked outside and checked the pressure again on the cold side and it was at like 150 PSI! (OMFGZ) I was kind of worried about it so I took the pressure down to 55. I turned the car back on and the AC wasn’t blowing cold. Oh and J-Rat was working so I couldn’t keep calling him and bugging him for advice. I drove the car around the block and I wasn’t getting any cold air at all. So I took it over to my mechanic and asked him for advice. He told me that when the car is off the system pressurizes so that the high and low side are at equal pressure (DOH) I felt like a retard since I basically lost all my gas.

Anyway I went back and put the 3rd can in the system. The pressure was at about 55 PSI on the low side at regular idle when the can was empty. I drove around the block and the AC was working really well! lowest temps at the vents was about 65F it was niiiiiice I came home parked and popped the hood to check pressure on the cold side again. And the pressure was about 25-30 PSI on the low side. Did the pressure go down because I was actually driving the car instead of it idling? Anyway just checking for opinions. I would call j-rat but he’s got allot on his plate right now and later today so I thought I would just post up here

EDIT: I just checked my pressure right now (30 minutes after I parked) it’s at about 125 PSI.

stylEmon

iTrader: (2)

this is a great thread. I will be attempting to charge my system this weekend.

Is there a difference between the R134a evaporator and the r12 evaporator?

What is used to clean the lines?

I have a new (oiled) nippendenso compressor, and a new evaporator. I am using the old lines and want to make sure they are clean.

rogrx7

iTrader: (11)

So is this the proper way to recharge your system. I've seen like 10 different ways in the thread.

Anyone still running freeze 12 for a while now?

staticguitar313

iTrader: (2)

i really wanna try ES-12a

rogrx7

iTrader: (11)

^^ I know Can we get a confirm on this method

jackhild59

iTrader: (7)

No, that's the improper way to charge your system;

Here is a technically correct how to written by a professional.

http://www.autoacforum.com/messagevi...&threadid=7931

Evacuate and Charging Procedure.

Attach a/c manifold gauges to the vehicle. Make sure you attach the correct hose to the proper service port. This is very important to prevent personal injury! Attach center (Yellow Hose) to a UL approved a/c vacuum pump. Open both of the dials on you’re a/c manifold gauge set. This will allow the system to be evacuated through both the low and hide side of the system. Turn your approved vacuum pump on starting the evacuation process. 30 minutes usually will be enough time. If vacuum pump has ballast read the owners manual concerning this option.

When system has achieved a state of 29.9 hg’s of vacuum close both dials on the a/c gauge set. You may loose up to 1 hg for every 1000 feet above sea level depending on the capacity and quality of pump. At this point wait 5 to 10 minutes letting the vacuum boil off any moisture trapped in the refrigerant oil. This is also a good time to watch and see if vacuum has returned to a zero state. If so you need to check for leaks in the system. Assuming the system is holding a vacuum after letting the moisture boil off repeat the evacuation procedure again. This process may need to be done a few times before all moisture has been removed and you see no degradation in vacuum after closing both dials for 5 to 10 minutes.

With both dials closed remove the center charging hose attached to the vacuum pump and connect it to either a can tap and refrigerant or 30lbs refrigerant cylinder. Open the valve on either the can tap or 30lbs cylinder allowing refrigerant into the charging hose. With refrigerant in the charging hose slowly crack this hose at the manifold gauge bleeding off any air that may have gotten trapped when moving from the vacuum pump to the refrigerant source. Only the slightest amount of refrigerant should be released in this process so be sure to tighten the charging line quickly!

Open only the low side dial on you’re a/c gauges allowing refrigerant to flow into the system. Again I stress the high side must be closed or you may cause personal injury to yourself or others! Start vehicle and turn on the a/c system with blower on the highest speed. In some cases if the compressor clutch has not engaged you may need to by pass the low pressure cut out/cycling switch. Refrigerant should be charged as a gas but in some cases it may be necessary to charge as a liquid. Be careful not to slug the compressor with liquid refrigerant! Charge system to OEM amounts and pressures if you are using the refrigerant the system was designed for. If vehicle is has been or is being converted start with about 60 percent of the original charging amount. After getting 60 percent of the original charge slowly add an ounce at a time until you reach the best possible vent temperature and pressure readings. If you do not know what your systems operating pressures are you can use the 2.2 x the ambient temperature as a guide. This should only be used as a guide as many systems will need more or less refrigerant to achieve proper cooling.

Having a weak fan clutch or an inoperative electric fan will cause system pressures to be incorrect. So make sure these components are working correctly before charging a system!

In lower ambient climates, doors and or windows of the vehicle maybe required to be open to achieve proper cooling when charging the a/c system.


Icemark and many other warm climate users do.

Boostmaniac

I heart this thread.

micah

I've been looking at picking up a vacuum pump and pulling the vacuum myself for a recharge.

Would something like this: http://www.harborfreight.com/cpi/cta...emnumber=92475
work fine?

jackhild59

iTrader: (7)

Tell you what. Let's run a public experiment. This is not a F/S offer, this is a mutually funded experiment in automotive A/C for the education of the RX7Club at large.

I have 3 cans of enviro-safe 12a I will 'provide' to you. How bout $20 shipping for all three of them. Thats $20 for shipping all three free cans to your door.

Charge your car with any R134a can tap and hose.

If you like the stuff, let me know and I will refund your half, or $10 of the shipping money. Not acceptable is a 'well it is better than no A/C at all'. The Coldfire's of the North say it is wonderful stuff. Either it is wonderful, or it sucks.

Let's define wonderful as in it will achieve 38* center vent, recirc on high fan speed with the outside temp 100*f. Center vent temps of 45* recirc on high fan in town stop and go city streets under 40 mph, 100*f day. My 90vert R12 system easily does these temps.


So, let me restate. If it works, you have cold A/C for $10. And I will shut up about these types of HC refrigerants.

If it doesn't work, you will have only wasted $20. That's less than if you buy it online somewhere else. And that case, we have verified results that can back my negative words regarding the HC refrigerants.

Try it. You might like it. You know you want to....

Edit:

BTW, if we are going to do this, we should do it before it starts to get hot in AZ.

jackhild59

iTrader: (7)

Those vacuum pumps will really work over your compressor. They do not pull a deep enough vacuum to remove moisture from the system. If you are evacuating and flushing the compressor oil, replacing the drier, you would probably be ok. If you are trying to dry out a system that has been open (no pressure is the same as open) for a while it is insufficient.

You can 'rent' vacuum pumps at autozone. The rental is free.

micah

Cool. didn't realize autozone had things like that. I'll give'em a try. And yes.. trying to dry out a system that has been open for a while. In fact, re-assembling the system with new o-rings since I just gutted my car. I was going to have a shop do it, but after I got a few quotes, I figured it would probably be cheaper to do it myself.

jackhild59

iTrader: (7)

Ok, this is pretty simple. The 'high side' and 'low side' only applies while the a/c is actually running. When you shut it off, the pressure equalizes between the two sides. IGNORE the pressures when the system is off and you will be fine.

I suspect that you are quite undercharged at this point. 65* may feel nice, but tells me you are a long way from a proper charge. You should easily be into the mid to low 40's F. If there is not enough refrigerant, the compressor will short cycle and you may burn out the compressor clutch.


Charge the system with the engine running at about 2000 rpm. You need a large fan blowing toward the front of the car. This is not to simulate driving, it is to make sure the hot air from the A/C and radiator is not recycled into the front of the condenser while the car is stationary and the hood is open.. If this is not done, the high side pressures will be too high and then you will probably under charge the system.

Charging by pressure, topping up, is an art and you need lots of experience and good judgment to pull it off without overcharging the system.

It's best to completely vacuum the system then add the entire calculated amount of refrigerant.

Johnsen recommends about 90% of the original R12 capacity. 90% of 29oz =about 26oz. Since Freeze12 comes in 12 oz cans, 2 full cans will probably do the job pretty nicely. If you add some of the third can, be very careful to not overcharge. Just really give it a squirt, then stop. Overcharge is worse than slight undercharge.

Good luck!

jackhild59

iTrader: (7)

DIY is the best on A/C. I will be glad to help you with any questions you have, just pm or post. I keep an eye out for A/C threads, because that is a place where I am qualified to help members.

The way it works is that you put a deposit down on the pump. When you return it, they refund your deposit. Free is nice.

You have 90 Days to return the 'rented' tool. if you don't return it in 90 days, it is yours and your deposit is not returned.

I have several tools I rented from them that I kept on purpose because they were handy to have close. I have rented the vacuum pump several times in the past, now I have my own.

micah

yeah, I've rented pullers and stuff from them before. I'm familiar with the deposit system.. just didn't realize they had such specialized stuff.. Is their pump specifically for AC or will I need some adapter or something?

You should really write a write-up on this for the FC. Feel free to use my wiki.
In fact, here: http://www.rotorwiki.com/index.php?t...ge&action=edit

I think the FC community could really use a nice simple walkthrough.

jackhild59

iTrader: (7)

The write up I posted above is better than I could ever do. It is good enough.

You can also rent gauges from autozone.

The vacuum pump is for refrigeration and has connectors with threads for R12 or R134a. Adapters for Freeze 12 you would need to get from a Dealer that handles that refrigerant.
http://cgi.ebay.com/ebaymotors/Freez...32068099QQrdZ1

You can pull the vacuum and dry the system with the original r12 connectors, 1/4" flare on the low side and 3/ 16 flare on the high side. Then charge into the gauges with the above adapter.

Good Luck!

jackhild59

iTrader: (7)

If you are charging with R12 and using mineral oil, you can use mineral spirits as a flush. blow the residue out of the lines with an air nozzle from an air compressor.

If your vacuum pump can pull a 29.9" Hg vacuum, that will remove all the mineral spirits residue and it will be fine for Ester and PAG as well.

If you are charging with ester or pag and your vacuum pump cannot attain this level of vacuum, do an after flush of nonflammable brake cleaner followed by some more compressed air.

Flush each line/part separately. Do not flush into the compressor! Do not flush the evaporator or the expansion valve, especially if they are on the car. Take them off the car, remove the expansion valve from the evaporator and then flush the evaporator core. Same thing with the condenser. Flush it separately and off the car is easier. Do not flush the drier (replace it).

CarzArKoo1

i was thinking carry a cooler in your fc where you can put it behind your seats and put some beverages in there, stay cool while its hot

CarzArKoo1

no A/c require, all you need is a cold drink

jackhild59

iTrader: (7)

And if you drink oh say 5-6 of those beverages, you get a free trip in back of an air conditioned car to sleep in an air conditioned 'room' with someone who just might like to

Now, that's cool.

You must be from Northern Cali. Usually it's the Canucks that troll the A/C threads.

rogrx7

iTrader: (11)

jackhild59 thanks for all the information...I will try that.

J-Rat

iTrader: (2)

Anyone have any experience with Red Tek yet?

Sideways7

iTrader: (7)

You should get about 38-40 degree air if the a/c system is working properly. My daily driver ('93 MX-3) with freeze-12 gets those temperatures regardless of the outside temps.

jackhild59

iTrader: (7)

Red Tek, Duracool, Enviro Safe, ES12a, HC12a, OZ12a are all pretty much the same stuff-propane with some butane and some isobutane.