A/C recharge

I put a new evaporator and heater core in my XJ a couple weeks back.

I recharged it with an off the shelf R134 kit. This is where I am currently:

• with the compressor kicked on, the gauge shows about 42 PSI
• the a/c lines are cold to the touch and are perspiring
• the drain is draining plenty of residual moisture
• the a/c is blowing warm to hot with it set at any of the 3 a/c settings

heater control valve? blend doors?

Sounds like a damper door (blend door?) problem for sure.

Also 42 psi (if accurate, is too high for the low side!!!) Did you pull a vacuum first?

What year? Also could be a loss of vacuum to the AC controls!!!!!

Ecomike said:

Sounds like a damper door (blend door?) problem for sure. where is the blend door? in the dash or in the heater box?

Also 42 psi (if accurate, is too high for the low side!!!) Did you pull a vacuum first? No I didn't. I charged it from completely empty. I can't say that the gauge on the hose is 100% accurate. It shows the safe range between 35-45 PSI

What year? Also could be a loss of vacuum to the AC controls!!!!! 2001.

Click to expand...

I did drive it today with the A/C on and it was blowing cool, just not cold. Also, when I fired it up this morning I got a pretty mean squeal from the belt (assuming the AC clutch) until I got the bottom of my drive way and hit the gas to accelerate. It didn't do that the second time that I started it up - after my meeting about 2 hours later.

If you didn't pull a GOOD LONG vacuum, it's just a giant crap shoot.

42 LBS of 134a = 47 degrees at evaporator entrance.

You should be in the neighborhood of 27 LBS = 30 degrees

To really know what is going on in your system it needs a vacuum pull and the factory specified weight of refrigerant put in.

I figured out the issue. The blend door actuator is working fine. However, there is something catching on the blend door going from hot to cold.

It goes from cold to hot fine, but catches the other way. I pulled the actuator out and turned the door with the use of a pair of pilers. I can get the door past the obstruction that way, but the motor isn't strong enough to get it past the obstruction.

Thoughts?

No vacuum pull means you left air and water vapor in the AC system, that means accelerated internal corrosion, excess pressure on the high and low side (which is BAD), low cooling efficiency, and risk of ice forming and sealing off the expansion valve (I assume 2001 Xjs still used an expansion valve?).

Squeal could be a loose belt, or one of many things. Not sure the AC clutch engages that soon after a start up?

Ecomike said:

No vacuum pull means you left air and water vapor in the AC system, that means accelerated internal corrosion, excess pressure on the high and low side (which is BAD), low cooling efficiency, and risk of ice forming and sealing off the expansion valve (I assume 2001 Xjs still used an expansion valve?).

Click to expand...

The catch, when I turn it by hand, almost feels like it has to get past a piece of plastic or something that is sticking out in front of it. I can feel it tighten and then slacken off once it is past the obstruction. It really feels more like a blockage versus low vacuum. I'd have to suspect that if it was a vacuum issue that I'd see a slow down cold to hot as well as hot to cold.

I also suspect that perhaps when I reconstructed the heater box I may not have put it back in just right and something is obstructing it, be it debris, or it is just not seated correctly.

So, what is the solution? My though is to remove the motor, get a tiny pair of vice grips, attach them to the blend door post, and just open and close it manually...because I don't want to remove the heater box again!

I was referring to pulling a vacuum on the AC system to remove air and water vapor from the AC refrigerant lines before putting R-134-a in, I was not referring to the engine vacuum that operates some damper door valves.

I have not been that far into the dash before or fiddled with that door, so I can't help on that item.