How and how far to insert probe into evaporator?

[ManniB]

I have completely restored the evaporator of my '80 SC. Cleaned motor and evaporator fins and replaced all the foam seals. Installation went smooth except one thing. I cannot get the temperature probe in between the evaporator fins.

I did take lots of pictures during disassembly, but unfortunately none of them shows how the probe was installed originally.

There is a thin and delicate brass tube that needs to be inserted between the fins. The probe then is inserted into the tube. My question is does the tube go between the fins straight down or at an angle (obviously, it has to clear the coolant tubes in the core)? Must the brass tube completely be inserted or does it stick out of the case?

Thanks, Manfred

[Iciclehead]

It should go all the way. When I did mine, it took a little wiggling and fooling around to get it in place, but the intention of course is that the evaporator control capillary tube has maximum "signal" and thus prevent freezing up amongst other things.

D

[kuehl]

What would have been "good" is if you had straightened out the aluminum fins where the probe was previously so that when you re-insert the brass sleeve, with the aluminum thermal sensing tube inside, it will make better contact with the fins. A good all around fin contact insures the thermostat will "see" the temperature of the core and cycle the compressor on or off according to the thermostat setting.

The brass sleeve, with the aluminum thermal sensing tube inside, should be inserted all the way into the top of evaporator box until the top of the sleeve is flush with the top of box.

Depending upon which style evaporator you are using, pre 86, 86+, or a serpentine, will determine the angle the brass sleeve is inserted.

Assuming you have a pre-86 evaporator (the tubes are copper in the coil)
you can use a 75 degree angle: looking from the LH front fender toward the evaporator box.

Be Careful You Do NOT bend the aluminum sensing tube too sharply or break the tube, otherwise the thermostat won't function and you will need to replace the entire thermostat.

[dshepp806]

Is the angle at 90 degrees for +86?

Thanks for the info, KUEHL!!!!!!!!!!!!

BEST!

Doyle

[kuehl]

If you buy a Kuehl evaporator you don't have to worry about this stuff

Originally Posted by dshepp806

Is the angle at 90 degrees for +86?

Thanks for the info, KUEHL!!!!!!!!!!!!

BEST!

Doyle

[ManniB]

Originally Posted by kuehl

What would have been "good" is if you had straightened out the aluminum fins where the probe was previously so that when you re-insert the brass sleeve, with the aluminum thermal sensing tube inside, it will make better contact with the fins. A good all around fin contact insures the thermostat will "see" the temperature of the core and cycle the compressor on or off according to the thermostat setting.

The brass sleeve, with the aluminum thermal sensing tube inside, should be inserted all the way into the top of evaporator box until the top of the sleeve is flush with the top of box.

Depending upon which style evaporator you are using, pre 86, 86+, or a serpentine, will determine the angle the brass sleeve is inserted.

Assuming you have a pre-86 evaporator (the tubes are copper in the coil)
you can use a 75 degree angle: looking from the LH front fender toward the evaporator box.

Be Careful You Do NOT bend the aluminum sensing tube too sharply or break the tube, otherwise the thermostat won't function and you will need to replace the entire thermostat.

Thanks to Kuehl's (Cools) description, it was easy to install the probe. The trick is the angle at which it has to be inserted between the fins. I had to first remove the evaporator box again, disassemble it and straighten the fins. I then used a rod with the same diameter (3.5 mm) to first create a path for the sensor tube between the fins (which is really delicate). After reassembly, the tube and sensor went in easily.

- Manfred

[wwest]

Originally Posted by kuehl

If you buy a Kuehl evaporator you don't have to worry about this stuff

Kuehl evaporator comes with a new/complete thermistor/electronic control system?

[wwest]

Originally Posted by ManniB

I have completely restored the evaporator of my '80 SC. Cleaned motor and evaporator fins and replaced all the foam seals. Installation went smooth except one thing. I cannot get the temperature probe in between the evaporator fins.

I did take lots of pictures during disassembly, but unfortunately none of them shows how the probe was installed originally.

There is a thin and delicate brass tube that needs to be inserted between the fins. The probe then is inserted into the tube. My question is does the tube go between the fins straight down or at an angle (obviously, it has to clear the coolant tubes in the core)? Must the brass tube completely be inserted or does it stick out of the case?

Thanks, Manfred

I would first use "standard" ice bucket to adjust/calibrate the control such the compressor circuit opens at 32F.

[kuehl]

Hey! Look what the wind blew in.

HAPPY NEW YEAR WWEST!

[SilberUrS6]

Originally Posted by kuehl

Hey! Look what the wind blew in.

Wirbelsturm?

[wwest]

Originally Posted by kuehl

Hey! Look what the wind blew in.

HAPPY NEW YEAR WWEST!

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