Alexei,

Make sure you have the rubber seal installed on forward edge of the wiper cowling cover (at the base of the hood)...if this is missing, damaged, or incorrectly installed you are sucking more hot air from the engine compartment into the HVAC system...and will make a BIG difference.

In reality as mentioned, it is impossible for the front A/C to be as cold as the rear A/C due to the design...but it shouldn't be a dramatic difference.

To eliminate the Heater Valve as the issue simply use a pair of "hose pliers" and as a test (only) clamp off the flow of the heater hose.

Hope that helps,

 

In my '89, the recirc flap is open and directing cabin air to the front evaporator when the AC button is on and the temp lever all the way to the left. If yours is closed it is trying to cool outside air rather than cabin air.

I think the '87 is supposed to work the same way. If your recirc flap is closed, it's likely either the vacuum diaphragm is leaking or the low temp slider switch isn't closing.

Replacing the recirc and comb flap diaphragms made a huge difference in my car's AC performance.

 

You funny dr bob...

 

Pretty much need to do this with the whole dash apart, so you can get the heater core and the evaporator out with the whole HVAC air handler. This is a WYAIT job when there is some other reason to have the whole dash out and apart. Not a Saturday morning clinic project.

 

How dumb can one be? I somehow managed to install heater valve BACKWARDS.

I heard one can replace heater valve without draining coolant from the engine. What is the best way to catch coolant as it will start leaking once I disconnect valve from the rubber hoses? Also, last time I had a hard time getting those hose clamps loose - I just couldn't find the right screwdriver. Any special size needed for them?

 

Put some paper towels under the heater valve when you take it apart. There is not too much coolant leaking when you undo the hose clamps. I usually use a nut driver to undo the hose clamps. Just be careful to not over tighten when you install them back.