Another AC Question

I have 98 Tahoe LT 5.7. The rear air blows cool and the front air blows hot. My rear air began to blow a little on the hot side and I add 134a. Fixed the problem. (I followed the directions and put the proper amount in) One month later (I hardly drive it because I travel so much but I need to get this fixed because I will be using he car more now.) Now my a/c is warm in the rear again. When I took the reading for the 134a level the gauge indicated that the amount of 134 is to high (in the red) then the compressor will cut on and the level will drop indicating that I need to add more 134.

I am new to this and have begun to enjoy working on cars over the last couple of years. I would love to know what to do but it may be over my head. I just want to understand what is going on with this thing and better understand it!

Two questions:
1. what is causing the ac difference between the rear and front?
2. Why is the reading jumping all over the place when the compressor comes on?

Thanks for your help, this is an awesome forum.

You need to get a set of guages and do it right. If you are using something that came with an A/C refill kit they are junk. You also need to test tempurature at the same time as the pressure. The pressure will very as the compressor cycles on and off.

I have 98 Tahoe LT 5.7. The rear air blows cool and the front air blows hot. My rear air began to blow a little on the hot side and I add 134a. Fixed the problem. (I followed the directions and put the proper amount in) One month later (I hardly drive it because I travel so much but I need to get this fixed because I will be using he car more now.) Now my a/c is warm in the rear again. When I took the reading for the 134a level the gauge indicated that the amount of 134 is to high (in the red) then the compressor will cut on and the level will drop indicating that I need to add more 134.

I am new to this and have begun to enjoy working on cars over the last couple of years. I would love to know what to do but it may be over my head. I just want to understand what is going on with this thing and better understand it!

Two questions:
1. what is causing the ac difference between the rear and front?
2. Why is the reading jumping all over the place when the compressor comes on?

Thanks for your help, this is an awesome forum.

Welcome to AF.
If you used a one hose one gauge wal mart type death with stop leak and other crap you probably have done killed it.:grinyes:
What did the can say was in it?

Get a set of the proper recharging gauges with low and high side gauge and give us you pressure readings at idle and at 2 K rpm.

Wal Mart DEATH KITS

You cannot properly and safely recharge an air condition system with them.

The one side stop and go gauge does not tell you what your system is doing or is over charged or undercharged.
A overcharged or malfunction air condition system can reach over 500 lbs of pressure.
Enough to blow up that can or system and freeze you at first and the burn you or blind you and if any propane /butane in there blow and light you up.

The stop leak crap and who knows what kind of oil in the kits there will stop your system for sure.
Just like pouring super glue in it.
And some kits even contain freon with a butane mixer.
Good for a big blast.

If you are going to do it do it right and safe.
Here is what you need to start with.
http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=RefrigerantGaugeSets

In the older days you could just throw in a can and go.
But over the years just adding freon is getting harder to do.
Newer systems have to have the correct amount of freon down to the ounces.
Most will need pumped down and vacuumed down and the right and amount of oil and a set amount freon charge installed to get the air to cool right and the system to last.
If an air condition is low there is usually a leak that needs fixed and also a lose of lubricating oil from system.
Also air and moisture enters a low system
If you are going to try to do it get the proper type air condition gauge set with the low and high side gauges.
Hook up the gauges and get a reading with compressor running at idle and at 2000 rpm on the high and low side.
Post back pressure reading and we can help you.
MT

had same problem ur freon level is still below pressure i made the mistake of buying the death kit also it said it was running great took it to a local shop and the gasket on top of the compressor was leaking replaced and recharged it about 400.00 but both blow ice cold now