Not so cold A/C

Like the title says, my A/C doesn't seem to be removing the heat very well.
I bought a set of gauges from HF and these were my readings. It was in the upper 70s and the discharge temp was about 50.

 

Looks pretty low to me on both sides. From memory (haven't charged a system with just gauges in several years) I'd expect about double those pressures on each side, although I don't think I did much A/C work when it was that cool... usually more like 85+.

When you say discharge temp, you talking air out the vents? And what's it do when it's hotter? 50 isn't bad overall, but it could be bad if it can only hold that when it's just 20 degrees warmer.

 

is that picture taken with the engine running amd AC on? or is it engine off and cold...more info may yeild some clues.

 

It’s hard to tell what’s going on with a picture of gauges. What are the gauges reading with the vehicle running and A/C on? Taco compressors go bad all the time. I wouldn’t be surprised if that was the issue. Do you have power and ground at the compressor?

 

I'd hope it's running, with a 100psi pressure differential.

 

Looks to me like your charge is low. Low side should be closer to 30 PSI, High side should be closer to 225-250 or so.

OP has a small leak.

 

agreed, but I have seen stranger things.

 

This. with engine/compressor off, pressures would be equal.

 

are you on your second compressor?

 

I've seen some strange ones (effing Chrysler products...) but that would take the cake for me. Pressures don't look wretchedly far off for how cool it is, 50 degree vent temp isn't bad- can't do any better than 32 at the evaporator or it'll ice up. Like I said though, it's relatively cool, and if it's low (which it no doubt is) you'll quickly hit the thermal capacity as the ambient temp goes up and be getting that same 20 degree differential, or less. 70 degree vent temp when it's 90 degrees is crap...

 

You are low on charge. You want to be more at the 80 pound mark on the low side.

*edit* this means you have a refrigerant leak. I don’t know how it works in the states but in Canada you are not aloud to charge with refrigerant until the leak is repaired.

 

No. You want to be at around 25-30 psi on the low side, with engine running, compressor on. 225-250 on the high side.

 

Anyone have the factory specs for lbs of refrigerant and target PSI ranges?

 

It should be on a sticker under hood. Also look on the radiator cowl. The amount has not changed since '05 and is 20.1-22.22 oz. (570-630 grams).

I might also offer a friendly piece of advice. This system must be charged by weight and weight alone. Notice the very narrow range. The system likes to perform poorly if slightly overcharged or slightly undercharged. The gauges must be used for evac., filling and troubleshooting but can get you into trouble real fast if you don't have a ton of experience interpreting them and monitoring the surrounding temps of the room, in front of the evaporator, and other stuff.

 

This. On a 70 degree day you should have at least over 200 on the high side, when it gets up in the high 80s you should see 250 to 300 roughly

This. You really need a machine that can calculate with a scale

 

Sorry you are right I’m thinking of R22! I would say 30 pounds is still low for r134. It puts you too close to freezing the evap. Either way it’s low on refrigerant.

 

Wow, thanks all for the replies. That pic was taken with the engine running, recirc on, vents selected and probed with a thermomometer at the vent left of the radio.

@Taco'09 that is a not a lot of wiggle room for the amount of r134.

Now that ppl are saying it's low, maybe i should just have it evacuated and replace all the o rings and those 2 filters behind what I believe is the expansion valve at the firewall myself. Whereas it's an 06, might as well do it all in one fell swoop. It would seriously piss me off to find and fix one leak only to have another show up a few weeks later.

 

Check this, its been a while since I watched this video, but I believe it's for an early Gen2 Tacoma. There's a few more videos in this series about changing the compressor and finding the leak using dye.



-J

 

Yep, on an '06 that is exactly what I would do. Also, use the Toyota seals and not the generic ones IMHO they are so much better. I've got a list of the Toyota one somewhere here and have posted their part numbers and their location so I shall try to dug that up for you.

I like to work quickly when I have the fittings off so that the system stays open as little as possible and humid air does not have a chance to contaminate. Also look at the micro-filter just ahead of the valve for any signs of debris. If you find metal-like stuff there stop and reevaluate as the compressor may be about to go and that would ruin your day, in fact it would ruin many days if it grenades and contaminates the system. Do not add any additional oil unless a component is replaced such as the compressor or condenser, etc. or a hose blew or there is a major leak. Always ask first.

I vote to stay away from the suicide cans and recommend a pro recharge by exact weight I note above. I'm a big advocate of DIY things on our trucks but the AC system is not one of them.

 

Part numbers. Here are the numbers for the seals. Also listed are various other parts you may encounter.

90210 Series Seals
Part Number Qty. Where Used
- 90210-A0001, takes 1, used on top front side (engine side) of TXV valve.
- 90210-A0002, takes 4, used on the bottom of both sides of the TXV, and the compressor outlet, and the condenser inlet
- 90210-A0003, takes 1, used on the outlet of the condenser
- 90210-A0004, takes 2, used on the top of the TXV on evaporator side, and the low side (inlet) connection on the compressor

90301 Series Seals and Special Black Plastic Couplings
Part Number Qty. Where Used
- 90301-A0006, takes 2, both used under the suction coupling next to firewall, this is the larger diameter of the two lines and heads back to compressor; the black plastic coupling is 88718--01180
- 90301-A0010, takes 1, used under high pressure switch on line from condenser to evaporator near radiator
- 90301-A0012, takes 2, both used under the high pressure pipe coupling next to firewall, this is the smaller diameter of the two lines; the black plastic high pressure coupling is 88718-01190

Inline Filter and TXV Valve
- 88377-04010, takes 1, special filter at TXV valve
- 88515-04060, takes 1, this is the TXV valve kit, it includes the filter, new mounting screws, inlet manifold to the TXV and two O-rings; an aftermarket TXV is also available but if you reuse the manifold use the new seals identified in the 90210 series above and the inline filter 88377-04010 identified immediately above.

Service Ports (Valve Cores)
Yes, sometimes these leak. The Toyota ones are a complete rip off. At one time they were around $15 ea. Perhaps that has changed. I will list their part numbers anyway. However, you can get both usually from a HVAC supply house and elsewhere for cheap. The low pressure one is just a traditional Schrader valve core the same size as in tires. The high pressure one in the line in front of the condenser is just an ACME core. They need to be compatible with R134.

- 88374-04020, 1 required, on smaller diameter high pressure line in front of condenser
- 88374-04030, 1 required, on larger diameter return line back to compressor