[xxxotic]

I had Tony Waas heater bypass installed on my car and almost always drive with it on and the temperature setting set to cold, not that it matters since it bypasses the heater. Every few months I test it to make sure that the heater works.

It was cold a few weeks ago so I used the heater and turned it up and it worked fine, but I noticed a coolant leak of about 4 or 5 ounces under the car coming out of the passenger side hole that was drilled as part of the service bulletin to avoid having water collect near the resistor pack for the a/c controls.

Since then, I have a leak under the car a few hours or days after I park it, or I dont have a leak, but notice that their is one after I start up the car and pull out of the garage. I took off the front access panels and their attachments and didnt see anything leaking around the bypass valves, and also took off the front undertray to make sure the lines werent leaking where the pipes connect to the hose. The only thing that I noticed was a little wet was the connection underneath the heater matrix. There is a box that say Bergstom on it and it has 2 hose connections going into it. The area underneath the connection towards the front of the car is where it appears to be wet.

I am assuming that this is the heater core and since it is normally bypassed, no coolant would be flowing through it and that is why I never had a leak before. The bypass is shut off after the ignition is turned off, so maybe some coolant is flowing through heater core and leaking out later on? I have been experimenting to see what causes it to appear intermittently to no avail. I have been alternating leaving the temperature knob to hot when starting and shutting off the car, and vise versa but cant find a pattern.

But I was wondering, what happens when you turn the temperature knob up on the car to make it warmer? Since coolant is normally going thru the matrix when the system isnt bypassed, what makes the heater work? Is coolant going somewhere else instead that gets hot when you turn the knob and I am not looking in the right place? I just hope that I dont have a hole in the heater matrix housing that is causing the leak, since I cant figure out how to even access it.

 

[holmz]

How do you know it is coolant?
Do you have AC?
Of could rain be coming out that has collected?

In fact... what was the source of the water that required the holes to be drilled I the service bulletin?

 

[xxxotic]

How do you know it is coolant?
Do you have AC?
Of could rain be coming out that has collected?

In fact... what was the source of the water that required the holes to be drilled I the service bulletin?

I know that it is coolant because of the color and smell.
My A/c is working fine.
I got stuck in a major Florida downpour a few weeks ago, but it seems like it is coolant, not rain since it doesnt appear to be diluted.

Here is the service bulletin. I guess water collects when it rains and has no where to go, causing the resistor pack for the blower fan to short out or get corroded.

 

[holmz]

I have seen that bulletin.

The main point was that the A/C unit produces water, and it was not certain that the fluid was coolant, nor that you considered the A/C as a water source.
Nor that the fluid was clearly not rain egressing out.

---------- back on topic -----------
How fast are you loosing coolant from the system?
And when you put a mark on the bottle does it loose a bit consistently? which probably is best to be checked with the engine cold.

 

[xxxotic]

I am not losing a lot of coolant. It only happened a few times and it was only after I used the heater. I noticed it was down to about the minimum mark when it used to be around the maximum amount on the bottle. When I added coolant and bleed the system with the heater on and the bypass off, the bottle started to overflow, but then after it sat all night it was back to the maximum mark. Since then I have let the car warm up two or three times with the bypass turned on and have only had a drop of coolant appear on the floor.

It looks like there is a small amount of dried up coolant on top of the heater matrix box, but their are 4 lines attached to the bypass valve. (See picture)

I think it is coming from one of the two lines on the left hand side of the picture. Those two lines let coolant go in and out of the heater matrix box in and out nipples when the bypass is turned off so it is either leaking where they connect to the valve, or to where they connect to the heater matrix box.

If the bypass is turned on, the coolant just goes from the top line on the right hand side, into the bottom line on the right hand side. However the bypass automatically shuts off when the car is turned off and their is no vacuum pressure, so that might be why only a drop gets through for a few seconds while the car is being started and the bypass valve is being activated.

I am going to try it tomorrow with the heater on and with the bypass turned off so that coolant goes into and out of all 4 lines and see if I can find where it is leaking. Attached is a picture of what the bypass valve looks like.