flyfisher117

Driving 2003 Tundra SR5, the AC sucks if the outside air is anything over 80 F. It blows cool air but it's not much, if the temp is below 80 the AC will freeze you out.

Blower is clean, condenser is not plugged, as far as I know these pickups DO NOT have a cabin filter what else could it be? I can't afford the $80 visit to Toyota but could the freon be old? Anyway I can check from home?

Any and all reccomendations appreciated!

Charchee

Freon will last forever as long as it's in the system. You likely have lost some of it due to a leak. If you don't want to spend the money at the shop, go to Walmart or a local parts house and get one of the recharge kits that has a gauge on it "must have the gauge". Get one that comes with a can of freon with dye in it. Hook it up to your low side service port. It will probably have a blue cap on it but your refill hose will only go on that port so you can't mess it up. Look at the gauge and see what pressure you have in it. It should read somewhere between 30 and 40 psi is it is full. If you see 25 or less, add some of the freon following the instructions on the kit. I wouldn't fill it past the point where you reach 35psi. It should be back to cooling normally at this point. If it's cooling good around 80 degrees ambient, you aren't going to need to add much in order to fill it back up. If / when it starts to act up again. Look at the hoses and fittings under the hood for signs of the dye. You may need to use a UV light, which they sell at parts stores for less than $10, and find the source of the leak. If it only runs a few days before it leaks down again, I would have it serviced professionally so they can pull a vacuum after the repair, add oil if necessary and change the dryer. Changing the dryer after the system is opened up is not an option. If they ask if you want to do it, the answer is YES. If, by change, the gauge shows that you are in the normal range, do not put that can of freon in it unless you want your issue to get expensive.

The little kit will cost upwards of $30 but it is reusable and will give you most if not all of the information you will get from a $75 ac check at a shop plus you can instantly add freon and dye without an additional charge.

Put that gauge on there and post what you see. I'll be glad to walk you through the whole thing and tell you what you need to do next. I'll be looking for your results and respond quickly when I see them.

flyfisher117

Thanks I will go grab one of those this evening or tomorrow. Id much rather spend $30 and get some knowledge out of it than $80 for the shop to tell me its all ok. Most all modern cars use 134a freon correct? Just wanted to check, I worked on a fishing boat in AK and the refrigeration unit on it did not have 134a and we did not know that when we serviced it.

To test pressure one should turn AC on and turn the blower on to max correct?

Charchee

Yes. 134A in 99.9% of all automotive applications since 1993 I think and Yes, test with the truck warmed up and ac on high. I bet you had R-22 in that boat. Learning AC is different than anything else I ever tried to learn. I can teach you half of it in an hour. The next 30% takes a year if you don't go to school for it and the last 20%, I can't tell you. I'm still learning.

flyfisher117

So it was 81 degree when I checked it and the pressure gauge came in right at 35-36 psi.

Charchee

I'm looking in to it. Stand by. Don't put any freon in it.

Charchee

Looks like you are charged up fine. I'm not real familliar with the Tundras but here are a few more things to check before you send it to the shop.

First, if you have a thermometer of some kind that will read down to the 40s like a kitchen or medical thermometer, insert it in your center vent while it's real hot and see what is actually coming out of the vent. Normally you will see between 40 and 50 degrees below ambient air temp if everything is working fine. You can have good cooling going on and still be hot due to air flow at the vent. Low air flow could be caused by a restriction in the evaporator box even if the fan is clear.

You said your condenser is not clogged up but take some kind of light and hold it up to the back of the condenser while you look through the front. Move it around and make sure there isn't something clogging the back side of it. The radiator may get in your way so you may have to take something thin and kind of probe it through the fins to verify they are clear. A restriction through the condenser can cause your issue.

Start the truck up without the ac on and look at the engine / radiator fan. If it's an electric fan, it should kick on as soon as you turn on the ac. If it doesn't, you may have an issue with the fan. Your symptom sounds to me like you may have an air flow through the condenser issue. If it isn't getting the right flow, it will cool until the outside air gets really hot and then the condenser does not have the ability to do it's thing before the expansion valve opens up.

Check to see that you have water dripping from beneath your truck when it's hot and the ac is on. If the little drip line gets plugged, your evap can fill with water and restrict the flow of air across it's fins. Your passenger side floorboard isn't damp is it?

These are just some simple and basic things to check for before we get into it any deeper. I'll be glad to go all in on this one but I need a little information first since my newest Toyota is a 2002 4runner. The systems are probably similar but I've never worked on one to this point.

Does your system include an ambient air temperature sensor? You would probably know you have one if you have a thermometer in the cab that reads the outside air temp. They play into some of the newer ac systems and may be something to look at. I don't think your system uses one of these but signs of a failed sensor include ac trouble at certain temps and a false reading on the in-cab thermometer like it saying 80 degrees when you know it is 95 outside.

Is your engine fan belt driven or electric?

Is your engine the V6 or V8?

We'll get it figured out. Look into the things above and let me know if you notice anything and post your temp reading at the vent along with outside air temp when you test it.

flyfisher117

V8 with belt driven fan. There is no ambient air sensor to my knowledge. Nothing in my cab tells me outside temps. No damp floor but water does drip out under passenger side of pickup.

I will try and track down a thermometer.