Hey everyone. I'm trying to trouble-shoot an AC/Heater issue.

When I got the truck, there was a little bit of water leaking from the under side of the Blower unit on the passenger side. I bypassed the heater hose through the firewall to stop the leak.

I went ahead and hooked it back up today and have the following symptoms:

I have some water dripping from what looks like some kind of overflow/drain under the hood coming from the firewall. This is on the passenger side of the car back low on the firewall. It is near the transmission dip stick and the passenger side exhaust. It's not a lot of water but it is a steady small stream.

Inside the cab, when you look up underneath the blower unit on the passenger side, you see three hoses coming in from the firewall. One red and the other two black. I have a little bit of water leaking down from two screw points in the plastic pan that appears to be just below the eval unit and along a seam that appears to have been patched.

So, Question 1: What would cause water to come out that “Overflow/drain”?

Question 2: Does it seem that the heater core is bad?

Question 3: How can you tell if you have a bad core?

If it is a bad core/evap unit, I need to remove it and have it fixed. Does anyone know of some instructions on how to remove that factory AC/blower unit? I removed two large bolts, one on each side of the unit but it obviously had many other attach points. Any hints as to the proper removal steps is appreciated.

Thanks,

Keith

 

Addendum to first question....

Is it possible to have a good A/C evaporator but a bad heater core? The reason I ask is that here in Texas with July and August coming on, I can do without a heater almost all year long. The A/C is a different thing.

I was thinking that I could get the A/C working first then worry about the heater later.

Keith

 

If you're going through all the trouble replacing an evaporator, you're better replacing the heater core at the same time as a matter of paying now or paying later with more headaches and another round of disassembly.

A heater core is cheap and I understand it's a major pain due to the AC system.

EDIT: I think what you may be seeing is normal. AC systems have a drain tube to drain away condensation that forms on the "heat" exchanger. Think of a cold can of beer/soda/pop on a warm day... condensation will form on the heat exchanger (the can) which either evaporates or accumulates enough to leave a ring on the table.

A bad core will fog up the windows, leave a sweet smell in the cab, or drip/leak green cooolant from the case.

 

Yes. The evap core is separate from the heater core. Both are within the evap case. The evap core has the freon running through it to cool and the heater core has the engine coolant going through it to heat. I can't post pics like Numberdummy can. Hopefully he'll catch this and post a pic.

 

Since you have factory air, the heater core is different than non-factory air models. It is also not reproduced nor available aftermarket. So if you replace the heater core, take it to a good radiator shop. They will solder your existing top and bottom tanks onto a new core.

 

I doubt there's anything wrong with the evaporator (19860). If you have anti-freeze and the heater core (18476) is leaking, you can usually smell it.

Leaking heater core will also cause the inside of the windshield to fog up...when the defroster is first turned on.

 

Thanks everyone. My first mission is to get the AC working. So, I'm not going to bother with the core right now. I think the evap is still good though.

I borrowed a vacuum pump and tried to charge the system but it wouldn't hold a vacuum. It's probably bad seals in the compressor. So, I'm looking for a local AC guy now who can put in a rebuilt compressor and trouble shoot the rest of the system.

Thanks for all your information.

Keith