Toyota Tundra Forums banner
1 - 13 of 13 Posts

·
Registered
Joined
·
222 Posts
Discussion Starter · #1 ·
I've always just charged into the low pressure side on my Fords and once there's enough in there fired up the engine with a/c on full and continued to charge. It would create a low pressure on the low side with the a/c running and allow you you to suck in the cans so to speak.

However I notice the Tundra PDF workshop manual I got says to charge the required amount into the high pressure side with engine off. Once done close valve, fire up engine and check for leaks.
Can the DIY guy at home really charge the required amount all at once into the high pressure side using those cans from the auto parts store? I realize you can't turn on the engine or a/c while charging into the high pressure side but this just seems odd to me.

Any experience or thoughts?

Thanks
Malcolm
 

·
Registered
Joined
·
541 Posts
Don't charge it through the high side.Charge the system through the low side with the engine running. The can's adapter fitting is sized for the low side anyways. The only problem is that R134a is charge level sensitive, it is realy difficult to charge the sytem, with just the right amount- by "eyeballing" a can.
 

·
Registered
Joined
·
222 Posts
Discussion Starter · #3 ·
Kovawa,

I have a 6 CFM Robinair vacuum pump and manifold gauge set so I could charge it through either port but charging on the high side just didn't seem right.

Manual says the vehicle takes approx 18 oz and it is sold in 12 oz cans locally so I got two cans. I won't have a way of telling when exactly 18 oz is in but I can go by pressures. I believe about 2.2 times ambient temps for high pressure side is about right. It's around 82F here right now so around 180 PSI on the high side should be where I want it.

Thanks for the info
Malcolm
 

·
Registered
Joined
·
3,510 Posts
Toyota Service manual i would think would probably work and be the correct way to service system? If i did not have all the special tools i would let someone that did have them do the service! The service procedure is in this PDF so just rifle thru till you get to it and if you wanta argue with Toyota procedure that is ok also!:)
 

Attachments

·
Registered
Joined
·
222 Posts
Discussion Starter · #5 ·
Hogwild, I have that PDF and I have a manifold gauge set, vacuum pump etc. I have just never heard of charging the system that way which is why I was asking for advice from those with some experience. As I'm sure any technician will tell you there is usually more than one way to skin a cat and various techs have their preferred methods. Just looking for something that will work for me and is something I'm familiar with and know I'm doing correctly.
 

·
Registered
Joined
·
222 Posts
Discussion Starter · #7 ·

·
Registered
Joined
·
3,058 Posts
Hmmm. I would've thought it was a plugged condensor. I looked in my troubleshooting tables, and it sounds like it's either a restriction between the compressor and condensor, or an excessively open TXV.
 

·
Registered
Joined
·
222 Posts
Discussion Starter · #9 ·
What's the TXV? is that the expansion valve? I took it out for a cruise tonight and sure enough even though it's cool evening air I could see same results as before.

Cools while cruising but come to a stop and it cycles a lot and vent temps go warm.
While in my driveway I took a garden hose with a nozzle on the end that sprays like a shower head and hosed the condenser and it appears to help a lot. High pressures drop drastically and a/c starts to cool. Using my IR gun I see the condenser very quickly jumps to around 160 F. That is also the temp of the hose coming to it from the compressor. That seems pretty warm to me.

I keep thinking there has to be some sort of fan or air flow issue so I unbolted the condenser again today and the radiator and using the garden hose lightly hosed out everything in hopes something I had missed in the past would clear out but as usual there's nothing in there and nothing changed.
 

·
Registered
Joined
·
3,058 Posts
TXV is the expansion valve. If the TXV is excessively open, the suction line should be cool to heavy sweat or frost. If there is a restriction between the compressor and condensor, the suction line should be slightly cool to warm. The restriction may be in the line or in the condensor tube itself.
 

·
Registered
Joined
·
222 Posts
Discussion Starter · #11 ·
I don't recall any lines under the hood been cool and definitely not cold to the touch or to where you'd see anything condensing on it. I believe all lines where fairly warm but maybe I didn't check all the correct lines. I'll recheck tomorrow. I recall some lines where covered in insulation material so you couldn't check those lines.
 

·
Retired Contributor
2010 Tundra/2015 4 Runner/2007 Prius
Joined
·
5,942 Posts
All of our Machines charge thru the high side, but like you said theres 2 ways to skin a cat. I personally have at home used a vac pump and charged thru the low side like you said and used the suction of the compressor to empty the cans, but that was back when we used R12. R134 is very temperamental and amount does matter. Our machines at work have scales so the amount added is supposed to be very exact and we usually charge thru thr high side, but can charge thru the low side if needed.
I dont think it really matters as long as you dont charge thru the high side like you said with the engine ON.

Make sure your getting good airflow thru the condensor. We have seen alot of wheelers get excessive mud/debris/leaves ect... between the condensor and the radiator. Make sure the fan clutch is spinning good too and not just turning lazily.

Post your pressures at IDLE and 2500 RPM..
Like Johnny5 said it sounds like stuck open expansion valve
 

·
Registered
Joined
·
222 Posts
Discussion Starter · #13 ·
Make sure your getting good airflow thru the condensor. We have seen alot of wheelers get excessive mud/debris/leaves ect... between the condensor and the radiator.
Mine are clean. I've pulled radiator and condenser apart a few times and clean as can be between them.

Make sure the fan clutch is spinning good too and not just turning lazily.
That part is suspect. I don't know what it should really be turning like. I replaced the fan clutch anyways. Got one from an 06 Tundra with only ahhh 12k miles on it I think. The guy switched to an electric fan and had it laying around.

Post your pressures at IDLE and 2500 RPM..
Like Johnny5 said it sounds like stuck open expansion valve
OK will get those readings.
 
1 - 13 of 13 Posts
Top