A/C leaking water into car

[Raycuda]

As the title states, my A/C is leaking water into the car. I tried pushing a rod through the drainage hole, but it didn't seem to help. What is my next step?

 

[Xcudame]

Unfortunately you might have a leaking heater core. Do you run straight water in your coolant system (some people do!)?

 

[Chryco Psycho]

The condensate needs to drain out of the heater box , something has to be blocking or diverting the water , you may have to remove the heater box & explore inside .

 

[Raycuda]

Unfortunately you might have a leaking heater core. Do you run straight water in your coolant system (some people do!)?

I do not run straight water, I run 50/50 water and coolant. I know for a fact that my heater core is not leaking, as I am not losing coolant, no smell, and it only happens when I run the A/C.

 

[Raycuda]

The condensate needs to drain out of the heater box , something has to be blocking or diverting the water , you may have to remove the heater box & explore inside .

How involved is it to remove the heater box?

 

[Chryco Psycho]

not at all easy

 

[sixpactogo]

How involved is it to remove the heater box?

It sounds like your evaporator pan has developed a leak or need some sort of attention. It is not good news but not the end of the world either.
You will have to evacuate or have the freon sucked down first. Then you can begin the task of removing the heater box. It is tedious work but once you unhook the plumbing under the hood for the coolant and AC, you can then remove the heater box nuts from the firewall. The rest of the work is under the dash, removing the duct work and cables. The heater box will come out as a complete unit and will then have to be taken apart to expose the evaporator. If the unit has never been rebuilt, you will want to do it at this time. You can get a rebuild Kit for it on Ebay. Loretta Fillmore at Detroit Muscle tech for around $40.00.
Here are some pics I have from rebuilding my Niece's 70 Challenger.

 

[fastmark]

It been awhile since I rebuilt an ebody and can’t remember if it has a steel pan under the evaporator core or not. Here’s what you might try first, though. Get a shop vac and try and suck out the drain tube. If it’s an obstruction, then it might get the blockage out. If that does not work, then out it comes for a rebuild. If I’ve got a AC box apart in my pile, I might could add to this thread to help. I’ll look at the shop.

 

[MoparCarGuy]

Ray,
I second the shop vac to attempt to clear the condensate drain tube at the firewall in the engine compartment. Hopefully it will clear and allow the condensate to flow down the firewall on the engine side.
--Jeff

 

[MoparCarGuy]

It is possible that leaves or other debris has entered the Fresh Air inlet (intake air) and ended up accumulating inside the evaporator area's floor. This debris can also clog the condensate drain tube. The aftermarket A/C systems from Vintage Air and Classic Auto Air block off the Fresh Air inlet opening to prevent accumulation of debris inside the box. Below is the factory A/C airflow showing how this can happen and block your drain tube.

 

[Xcudame]

You could also remove the blower motor as on AC equiped cars, it comes out from the engine bay - three nuts. It might let you see if there's blockage.

 

[MoparCarGuy]

Ray,
Click this VIDEO LINK of a guy taking the A/C blower motor out. He is doing a heater core replacement but at least he shows the A/C blower motor removal portion at 8:36 into the video. He had to remove the A/C lines to get the blower motor out. Hopefully, you will not have to do that on a 340 Cuda.
It looks like you can reach in and clean out any debris at the bottom near the drain hole without removing the entire box.

 

[Raycuda]

Ray,
Click this VIDEO LINK of a guy taking the A/C blower motor out. He is doing a heater core replacement but at least he shows the A/C blower motor removal portion at 8:36 into the video. He had to remove the A/C lines to get the blower motor out. Hopefully, you will not have to do that on a 340 Cuda.
It looks like you can reach in and clean out any debris at the bottom near the drain hole without removing the entire box.
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Thanks for the tip, I like this idea and will definitely give it a try.