Ask Me Help Desk - My car's AC is not blowing cold

My car's AC is not blowing cold

Many have told me it needs a Freon charge. I thought the system was sealed.
So maybe there is a leak? 2003 Toyota Echo

If it doesn't hold a charge for more than 10 years... its got a leak. Has it ever been recharged before now? If not recharge it and it will be junk before it needs another... if it was recharged in the last few years its got a leak... if it was recharged recently its got a big leak.

It has been 10 years working okay. Never had any trouble

Quote:

Originally Posted by pastor1189

It has been 10 years working okay. Never had any trouble

Recharge it... I bet it will work for a very long time... a leak that takes 10 years to deplete the system is going to be difficult if not impossible to find much less fix.

Okay thanks

If it all leaks out fairly quick after a recharge then you actually do have a much bigger problem... but I think the likelihood of that is not as great as a long term minuscule leak is.

Fine advice

I bought my last Mercedes for really cheap because of that... shop quoted them a crazy high price to fix the system, so I used that as a negotiation point to get it cheap... really cheap... I checked it out... found no leak that was detectible.. recharged it and it worked for 7 years without a recharge... so now 9 years after I bought it, it actually has developed a leak... but the car is now 30 years old. I can rebuild the A/C system for less than $500 in new parts...

Even though the air coming out of the vents is not cold, see if the refrigerant lines are cold under the hood while the system is running. Also, verify that the compressor is running.

Since system capacities are so small on modern systems, it doesn't take much of a loss in freon to cause problems. The system's capacity should be on a decal under the hood. 80% of most leaks are from the valves, where the manifold gauge set's low and high pressure lines are attached. After verifying that the compressor runs, attach a manifold gauge set. Check the static pressure with the system off and check the low and high pressure readings with the system running. Compare these readings with what they should be. Always wear goggles and gloves. If the compressor does not run, check all under hood and under dash fuses with a test light or multimeter.

If you determine the compressor runs fine and you suspect it's just the 134a freon level that is low, only use a manifold gauge set to add refrigerant to the low pressure side of the system. Attach the can of freon to the center service hose going to the manifold. It's always best to evacuate and recover the freon from the system first, vacuum the system for 35 minutes, wait 30 minutes and ensure there are no leaks, and recharge the system with the proper amount of freon. If there are any leaks, check around the low and high pressure ports first. The valve stems frequently get damaged and can be easily replaced. These are just some basics.

My son tells me it does go off and on. He told me last year, it did it for hour
And then came on cold. I use to add the gas years ago to other cars. 2003 Toyota echo
Should have a black cap with the letter L for low pressure line.

If the under hood refrigerant pipes get cold, then the problem may be with the blend door actuator. It may be jambed or it may need replacing.

Thanks I found the low pressure valve has a big L on it. I will do further test as you suggested

Quote:

Originally Posted by pastor1189

My son tells me it does go off and on. He told me last year, it did it for hour
and then came on cold. I use to add the gas years ago to other cars. 2003 Toyota echo
should have a black cap with the letter L for low pressure line.

If it comes on and off... then there is at least a charge high enough to not trip the low pressure switch which will switch the compressor off to prevent compressor failure. No refrigerant circulation = no oil circulation = bad.

There is such a thing as too much refrigerant as well... the system works best when it has exactly the right amount in it. Not too much and not too little.

Last night I looked under the.hood. I drop the hood. Today the AC ran all day good.
Very strange. Maybe there is valve that sticks/ED

Quote:

Originally Posted by pastor1189

Last night I looked under the.hood. I drop the hood. Today the AC ran all day good.
very strange. Maybe there is valve that sticks/ED

I'm thinking its more like an electrical gremlin. 10 year old car its possible... Unplug and replg anything you see attached to the AC system a couple times... unfortunately I don't know where they physically are on that car to tell you.

There should be a few.. low pressure switch,. high pressure switch, the clutch... An older Honda has a few relays additionally but you don't have that.. thats just pretty generic info.. Never worked on a Toyota.

Nothing is attached to the AC I though about buy the Arctic Freeze Kit which has a pressure gauge but the old idiom if it isn't broken, don't fix it tells me otherwise.

I don't like that Artic freeze crap...

I don't like any of the blends for reasons too lengthy to type here.

Put real R134 in a car built for R134.. and real R12 in a car built for R12...

Also... the right pressure on a 90 degree day is not the same as the right pressure on a 80 degree day or a 70 degree day.

I have a 2003 Toyota Echo.

Either know how to use a manifold gauge set or leave it alone--no exceptions! Artic Freeze kits almost guarantee that you'll damage the system.

Okay. Will just leave it alone. It is working fine now?