AirCon issues

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
Hey team.

My aircon sucks for two reasons. The cold isn't very cold, and the vent select is ratchet with a broken cog just like Cameron McPherson's was. it has been regassed and a new AC compressor installed, but my local mechanic is of the belief that I have a dodgy TX valve.

A what?

Can anyone shine a light on where the hell that is, how hard is it to replace, and the likelihood of that being my real issue? I can deal with the funky vent select, but I intend to visit Queensland soon, so I NEED AC.

Thank you.
 

Grey_Ghost

Leaving Skid Marks
Lifetime Member
Location
Australia (Duh?)
First Name
Gav
Drive
1997 Trigger PFL Manual Legnum.
TX valve controls the flow through the evaporator.
If it's not the compressor, not low on gas, yes. It is a lokell candidate
 

naughtika

OzVR4 Stalker
Location
Brisbane, QLD
First Name
Christian
Drive
'96 Galant VR4, '17 MB A180, '25 Macan GTS
unfortunately, you will have to de-gas it properly to replace the TX valve.

I think one of this is what you need
2018-10-08 12_12_52-HEATER,A_C.png
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
So where abouts is that located in the engine bay? And how much work am I looking at to change it?
 

VR45UM

Hesitantly Boosting
Location
Sydney
First Name
Andrew
Drive
2000 Mitsubishi Galant VR4
I have not done this repair, but from the looks of the diagram the TX valve is located in the dash/HVAC area on top of the evaporator.

Work would probably be
-Degas AC system
-Remove as much dash related shiz to get at the HVAC unit. (manual might shed some light on this procedure)
-Replace TX valve
-Reconnect Ac system and regas.
-Check cooling is hectic
-Refit your dash stuff.
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
Dash out. Just kill me :cry::cry:
 

jungle

3 AYC Bars
Lifetime Member
Location
QLD
First Name
Simon
Drive
1 PFL & 1 FL Legnum
I replaced mine a few weeks ago.
You'll need to degas it.
In the engine bay, remove the low and high pressure lines to the evaporator which is under the charcoal canister. Remove the charcoal canister to gain access to the 2 lines. You'll need a 10 & 12mm from memory. It's not easy and you'll need a small extension for both.

Once that's done, go back inside the car and remove the glove box and the metal bracket it sits on.
There are 2x12mm above and below the evaporator again you'll need long extension to access them.
Now the tricky part, to remove the evaporator itself. Be gentle with the plastic trim closer to the centre console. You'll know what i mean when you see it. You need to GENTLY bend it out of the way while remove ing the evaporator. It can be done without breaking it.
As stated above the TX valve is inside the evaporator housing. Easily separated (no pun intended) and then replaced with a new part. Your aircon guy will be able to source a new part.

The part itself is about $20
Hope that helps.
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
I replaced mine a few weeks ago.
You'll need to degas it.
In the engine bay, remove the low and high pressure lines to the evaporator which is under the charcoal canister. Remove the charcoal canister to gain access to the 2 lines. You'll need a 10 & 12mm from memory. It's not easy and you'll need a small extension for both.

Once that's done, go back inside the car and remove the glove box and the metal bracket it sits on.
There are 2x12mm above and below the evaporator again you'll need long extension to access them.
Now the tricky part, to remove the evaporator itself. Be gentle with the plastic trim closer to the centre console. You'll know what i mean when you see it. You need to GENTLY bend it out of the way while remove ing the evaporator. It can be done without breaking it.
As stated above the TX valve is inside the evaporator housing. Easily separated (no pun intended) and then replaced with a new part. Your aircon guy will be able to source a new part.

The part itself is about $20
Hope that helps.
I'm giving it a crack at the moment, and have pretty easily pulled apart all the glove box stuff. Do you have any tips for removing the charcoal canister? It looks like mine is held in by a bolt that is completely covered by the canister itself, which is extremely frustrating.
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
Well turns out I didn't even need to get to that bolt because I didn't understand how charcoal canisters are fitted. But on the plus side, a coolant line crumbled in the process :banghead::banghead::banghead:
 

jungle

3 AYC Bars
Lifetime Member
Location
QLD
First Name
Simon
Drive
1 PFL & 1 FL Legnum
So you found the charcoal canister just lifted off then?
 

Nitephyre

Flaccid Member
Lifetime Member
Location
ormeau@gc.qld.au
First Name
Matt :)
Drive
1963 Toyota Lite-Stout & 2002 Mitsubishi Legnum VR-4 Type-S
Well, I'm glad that the whole dash doesn't have to come out to change the TX valve. I had to replace the heater core earlier this year and that was a full dash out job (see my Larry thread). Never want to do that again.

I've been getting the issue of it initially being cold but then stops. It's worse in high heat-soak conditions i.e QLD from September :p. Does that sound like low gas or dodgy valve?
 
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