Location of TXV Valve, After or Before Evaporator?

[Z2TT]

Hello,

On my Soarer, My Expansion Valve is located After the Evaporator. Now as far as I know the expansion valve controls the rate of flow of gas to the evaporator, how can it do that if it's located after the Evaporator?

Thankyou.

[The Last Streetfighter]

Standard air condition circuit is:
Compression
Condensation
Thermostatic expansion
Evaporation
Repeat

[Z2TT]

That's right, but on my system clearly the TXV Valve is located after the evaporation.

On Mine it's

Compressor
Condensor
Reciever/Drier
Evaporator
Expansion Valve
Repeat.

I don't understand how the system can work like this.

[Z2TT]

Looks like I might have been wrong.

I have found something in the evaporator box that has a diaphram on it (located on the high pressure side), is this the TX valve?
It seems to have some sort of copper wire running from the diaphram

Here is a picture.

http://img44.imageshack.us/img44/2976/aircon.jpg

The can like thing on the left which has the low pressure line going to it and then exitting is what I thought was the TXV Valve,
But it looks like the TXV valve is the one with the diaphram on it.

So I'm wondering what is the purpose of that copper wire which goes from the diaphram to that thing on the left outside the evaporator box.

[2jzhilux]

the one that you have labeled some sort of diaphram is your tx valve

[matty12]

^^^ not quite,the bulb on the end of the tx valve controls filling of the evap.If it starts to warm it opens the tx,if it starts to cool it closes up.The tx valve main job is to keep the evap full,it also has the restriction to provide the pressure drop which is why it goes cold from the tx on.Its all low pressure from the tx back to the compressor.


Latter model stuff uses a block tx which has both high and low pressure sides run through it.

[cambelt]

The one inside is the TX valve and big thing outside is a regulator valve , id guess to stop too much going back to the pump .
The deleted the outside valve after about 1990 on most toyotas, and used a block type TX valve .
Dave

[matty12]

the last valve is used to maintain a constant low side pressure,very similar to what the VT onwards commodore use.

[Z2TT]

About that outside valve, how does it work though, as in who operates the amount of flow it lets back to the compressor?

Also notice that outside valve has a little copper wire from it that runs to the bottom side of the diaphram on the txv valve,
what is this for?

Thanks.

[cambelt]

The outside valve is spring controlled inside itself ,Its sucks itself open as required, ie system flow.
I,ll stand corrected if im wrong , the little copper pipe gives the TX valve the true suction reference at pump pressure ,and not at evap pressure as the reference would be mixed up by the regulator valve (outside valve)
Dave

[Z2TT]

So the copper wire that comes from that outside valve going to the TXV Valve is just for finer controlling of the amount the valve opens?

As in the wire that comes from the bulb pushes the valve open and the wire that comes from the outside valve pulls it open? Or am I wrong.