MisterRisky

Ahhhhh.... My apologies for being way off base. Sorry about that.

-JD

Cupcar#12

no worries,
after rereading the thread - i installed the INTERIOR diff flappers last night, and reconnected the front blower fuse, i'll see if that fixes the Heat always on issue. Hopefully it will if not - i will probably just remove the mixing chambers for the drive down to San Diego since have the heat always on in So Cal would be not fun.

Computamedic

I'm confused!! I was only aware of the flapper valves in the rear wheel wells. Are these internal flapper valves something unique to the Cup cars or is there something lurking in the back of my car that I didn't know about???

Dave

Cupcar#12

no they are in all 964's that i am awaire of
the part number that i'm talking about is 964 572 043 01 - <called a "Insert Bleeding" by porsche)
pictured here...


This is what i installed last night

The Mixing chambers are Called the "Heat Control Box" 964 572 087 00 (L) and 964 572 068 00 (R)
No 1. in this diagram



These are what i will pull out if it does not fix my heat on problem

The Flapper in the front blower is pictured previously and is inside the blower unit

Does that help

Computamedic

Rob,

Thanks for that. The part you mention is shown in PET as "Insert Ventilation" but the diagram doesn't make it at all clear where they fit. Have you any idea what the purpose of these things is???

Regards

Dave

dfinnegan

Those are for venting. To get air in you must get air out. They are right below the seat belt spool.

They also serve as mouse doors! . . . not that I know first hand, mind you :-)

Computamedic

Thanks for the explanation. I guess that's the function of the "valve" - air out but not mice in!!!

Dave

Cupcar#12

ok bringing this thread back......

My issues.... Heat on one side of the car (passanger)

I have a hammer this weekend which makes thinges easier

my current situation...
both mixing chamber flappers - report "Signal Unplausable" i.e. it cannot tell if it is wired correctly (appears to be) seized, or other....

Neither move with the hammer or with the CCU set to either setting (everything else does, so i am assuming the wiring is correct)

the pass side (right) was full open the left (drivs) Fully closed

i am assuming i have 2 bad servos for the flappers - am i off base here?

let me know - i have the hammer all weekend (and can get it any weekend) i opened the squirell cage area on one side to confirm

thanks
(trying to restore heat to the car for winter)

MisterRisky

Yes, two bad servos. Unhook the flappers just for good measure and see if the servos move. If not, bad servo. You can lay a multimeter across the servo wires just to make 100% sure you are getting current when the servo should be moving, but I suspect the servos.

Cupcar#12

k - neither servo's move when disconnected - so i will order some servo's and see if that fixes it (finally)

deep_uv

You can double check the servos once removed by using a 9v battery to actuate them.

I have one bad one right now which I have disonnected from the power after getting the door shut. Will be good enough until winter. Have you seen the prices on the replacement servos? Ridiculous. $200+

Steve

all623

Can anyone advise if the spongy covering on the A/C line can be removed, at least partially, where it wants to obstruct the moving arm on servo #4? I can hear the motor in the servo trying to turn but the arm doesn't always move which causes the flapper to be partially open or closed in accordance with the temp ****.

When I bought the car I noticed hot air coming in thru the driver vent and floor. The servo arm was stuck on the A/C pipe.

The A/C line will not move much, so will removing the A/C line covering solve the problem? Will it cause temperature or any other damage to the servo, firewall or anything else around it if it's bare? Strange how tight the tolerance on this was made.

mojorizing

Hi Anthony,
I looked at servo #4 on my car and at 6:30 (looking towards the back of the car at the servo arm) the arm touches the foam insulation. That's the suction line for the A/C, and it's there so that water doesn't condense on the cold hard pipe.

Now the end of the servo arm just touches the foam, doesn't dig into it. Does yours actually deform the foam as it strokes?

These servos have some torque as they have gearing inside the case. I can't believe that a little foam could stop these servos.

I would disconnect the linkage and stroke the servo. If it still hangs up, then it's not a problem with the damper that it's attached to.

Have you read this info? >>> http://www.porsche964.co.uk/technical/servos.htm

If you hear the motor turning in the servo, yet the arm isn't actuating, then it could be a stripped gear/shaft in the case.

Oh, yeah, if you remove some of the foam, condensation will form on the hard pipe, possibly dripping water down below that spot.

all623

I've seen the article.

The arm has been digging and creating wear in the foam in the area of the ball/socket of the arm when it swings closest to the foam. Also, near the base of the arm (on the bellows when it is open) it feels slightly restricted by the foam but can't say for sure since it's difficult to see under the A/C line what's happening.

I'll try your recommendation. I agree about the gears, if the arm is moving but not all the way open and closed gears could be stripped. I guess it's possible the restriction by the foam could have stripped the gears if there is enough resistance, over time?

Will definately not remove the foam, don't need dripping water! Thanks for the suggestions and info.

all623

I think I know the issue. After disconnecting the linkage, I can see the servo is fully operational. The tiny nut that attaches the servo arm is loose. Loose enough that when the linkage was making contact with the foam it would stop at that point.

I need to figure out now how to line up the servo arm before I retighten the nut and then reatach the linkage? I can check the article again you provided and maybe observe start / stop points of servo #2 as a reference. Appreciate your help!