slate blue

How many valves? I have replaced 2 so far, these operate the two dashboard vents, but I believe there must be one for the recirculation of the air. If so how do I access it?

Thanks

ROG100

There are 5 if you include the heater valve under the hood.
4 in the dash area.

You have to remove the blower motor and housing under the dash on the passenger side to get at the recirc valve.

Remove the wipers and lift the hood. Undo the two nuts at either end of the windshield valance.
Remove the hood hinge bolts on the blower side. You will need someone to help with supporting the hood.
Scribe around the hinge so you can align the hood back in the same position.

There are three bolts holding the blower in place IIRC.
Remove the housing from under the dash - you may have to remove the glove box.
The housing has mastic around the seal so requires some force to unseal it.

It really helps to have someone help you. One in the car and one outside.
A fairly straightforward job.
The actuator is inside the housing and can be replaced easily.

Good luck.
Roger

docmirror

There are a total of 5 actuators. There is an actuator for air recirculation. Getting to it is not easy. first you should test all the vacuum ports as described in the Nichols site, or simply search on HVAC for a recent post. I think it's the blue line

If you need to access the recirculation actuator to change it proceed as follows:

Disconnect the windshield washer lines. Remove the hood(scribe around the flange before loosening bolts) , loosen the nut on the pass(rite side) wiper and remove the wiper. Remove the screw holding the pass(rite) body colored trim strip under the wipers. It is found in the corner of the right side hood, a 10mm head, flanged bolt. The trim strip will now lift slightly. Remove the flimsy plastic cover over the wiper fluid reservior. You should now be able to see the blower motor.

The blower motor is held to the chassis by three 8mm self tapping screws. One can be viewed in the recess right rear corner of the fender. Remove it. Next, pry back the rubber tube connecting the output of the blower asm to the duct. The screw is in the plenum of the blower output, remove it.

Now move to the pass foot well. On airbag models only; Remove the glove box. Remove the glove box cross brace and hinges by removing the two 10mm nuts. You will need to lay on your back to get them out. All chassis; Pry back the pass side carpet, and remove the elecs wood cover. Look up at the recirculating air access. There is a door flap that is actuated by the vacuum actuator. It is normally closed, push on the door with a screwdriver and insure it is not stuck. Remove the last 8mm self tapping screw from the rear of the facia of that recirculating vent. Remove all the 10mm nuts holding the vent housing to the chassis. There is a metal flange across the firewall that will need to come off. Be careful of the wiring harness that runs across the firewall.

Back up to the right side engine bay. Remove the blower by tilting it and rotating it while lifting the wiper body colored flange. The motor will just barely slide out with the right tilt, and angle. Disconnect the motor connector and set the blower asm aside(I left mine connected and set it on the engine). Locate the vacuum line that disapears under the reciruclating air housing. I think it is blue. Disconnect that line by feeding your hand in the gap from the removed blower. Now, gently push down on that recirculating air housing. The housing should also be pryed from below as there is a mastic seal holding it to the chassis. You will need to angle the housing to get it out past the wiring harnesses.

Once the housing is out, the vacuum actuator can be accessed, and serviced. Note that this actuator is a different SIZE than the others. It requires a different PN (928 573 077 04?) from any of the big 3.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Install a new actuator, and insure nipple is oriented the same as when removed. Angle and push housing back up from pass footwell, and reapply mastic, or sealant around housing flange. While housing is PARTWAY in, before final fitting, attach vacuum hose to actuator nipple. This is a blind attachment, and can only be done by feel. Test vacuum! Install metal strip in back of housing, put on a few 10mm nuts finger tight. Install rubber connector boot on duct, and lift body colored trim to install blower. Orient blower on an angle, and it will slide in. Install two 8mm screws, one in blower output, and one in recessed corner. Attach blower cable.

Reattach body colored trim with screw. Install the flimsy plastic cover. Refit hood(line up scribe marks), attach fluid lines to hood fittings. Install pass side wiper, and nut. Test for recirculation, and visually inspect flap operation.

Drink beer.

Doc 90GT in resto, air recirc job complete.

From pass footwell, test operation of the recirculating flap. Install last 8mm screw holding blower. Install remaining 10mm nuts on housing flange.

docmirror

HAHAHHAHAHAHHAHAHHAHAHAHHAHHAHA!!!!! Rog - You flaming #%$&^%*@##$&$*^!!

ROG100

Doc,
I can see you are a detail person.
I missed out the drinking beer part.
Rog

slate blue

Guys thanks sooo much, this car is driving me crazy, so many things were wrong with the air cond. The only this now is the slight sucking noise you get when you turn the car off. Given that 2 valves were perished, I think there is a good chance the noise is another valve. I have replaced the vacuum one way valve and the heater tap valve is perfect. So is that the four? and I only have to change the recirculation valve for the 5th?

Cheers Greg

docmirror

IIRC, you choked a few down. Gotta add all the steps or the job won't get done right.

Doc

slate blue

Now I got the drinking part, but the bit before that?

ROG100

Greg,
One above your right knee when in the driving seat, two behind the center consol, the heater valve under the hood and the recirc valve makes it 5.
Roger

docmirror

Wait a bit, I just realized his car may be upside down. If it's right hand drive, reverse all the posts above to read "left" for "right" and vice-versa. I didn't notice he was posting from OZ.

Heater
Air recirc
Defroster
Foot well
Comb flap

I understand the Defroster(green?) valve is really a be-atch to reach. Comb flap on an airbag car requires surgury to the panel adjacent to the actuator valve to uncouple, and replace.

Doc

slate blue

Thanks Rog, you must be a very sick man, I have three 928s and I'm nearly insane, if I got to 4, I know I had just stepped over the mark. Hope you get help soon.

bd0nalds0n

I didn't think the defroster pod was hard to get to. Granted, the instrument pod has to come off, but I don't think it's very hard to do. The recirc pod was a much bigger PITA. Once you get the dash pod off, it's really easy to access the defroster vacuum pod.

UKKid35

Question for Doc about the recirculation flap:

Do you really have to remove the hood? The Pirtle write up for the recirculation flap doesn't mention hood removal.

http://members.rennlist.com/pirtle/svc_blo.html

The problem I have is that the defrost flap is inoperative, so I get hot air in my face when driving (or I freeze). So I want to deal with as many of those pesky actuators as possible in one go.

However Pirtle doesn't give any advice about the defrost flap other than "good luck", so is it really as easy as removing the pod as Brian says?

Ron V

Doc thanks for the write up, I'm in the middle of doing this. So far I have the Center console out, can see two of the actuators, and was pondering what to do next. This is great. I do need to make a beer run though.

the flyin' scotsman

Paul..........yes, you have to remove the hood. Its not that hard; the 2 struts and 2 each side hinge bolts.......make sure you scribe first to get positioning correct on the re build. You should get a helper though.........its light so worries of 'bonnet stress'

I asked the same question of the defrost flap/actuator and got excellent direction (Rennlist ) and yes you have to remove the pod. Do a search on defrost actuator.