Heater flapper box

Zacko · 03-07-2008, 01:09 PM

When heat lever arm is in position on(max) the flapper box is not fully closed. When lever arm is in off position everything looks right. Is there any adjustment to do??

Heat lever arm "on"

Flapper box(heat on)

Flapper box (heat off)

/Hans
911 3.0 SC -79

911Freak · 03-07-2008, 01:19 PM

I had the same issue...
FWIW:
I adjusted mine where the cable goes thru the clamping attachment on the flapper box..I have auto heating (disconnected) and it took me a few adjustments, I replaced the factory clamping device with one from a hardware store..small bit of compromise, I prefer totally closed as oppose to totally open, b/c I live in warm climate

While your in there, clean them up real good and maybe replace your heater hoses going to the flapper box's they look a little worse for wear, from the pic...

3.2 CAB · 03-07-2008, 01:21 PM

You should be able to get full closure . I would say to adjust cables where they mount on the flapper boxes. Also make sure that you heater levers are also in the correct position, when making the adjustments on the flapper cables.

911Freak · 03-07-2008, 01:31 PM

Quote:

Originally Posted by 3.2 CAB

You should be able to get full closure . I would say to adjust cables where they mount on the flapper boxes. Also make sure that you heater levers are also in the correct position, when making the adjustments on the flapper cables.

Excellent advice, forgot to mention the KEY step

Zacko · 03-07-2008, 01:35 PM

I could adjust them on the end of the wire, so they would be fully closed when heat is on. But then they would not be fully opened when heat is off??

/Hans
911 3.0 SC -79

911Freak · 03-07-2008, 01:46 PM

That's why I said "compromise"....
More important to you for heat full on or not?

I couldn't get them to swing full both ways so i chose to set it up to best suit my needs...

javadog · 03-07-2008, 01:49 PM

Here's a suggestion. If you want to take the time to remove them (and clean them up while you are there) you'll see how they work. You are looking only at the opening on the outside. What really matters is whether it is closing the passage inside that allows heated air to travel into the car. You want the cable adjusted so that when the heater is off, no air flows into the car.

It will be pretty obvious when you remove one.

JR

911boost · 911boost's Garage

Be careful not to snap any bolts when removing them if you go that route.

Zacko · 03-09-2008, 10:48 AM

Have also noticed that when the heater knob is in max position the heater lever only goes up half way. Have to pull the lever slowly by hand to max heat position. Is this right? or is there any adjustments to do here also ??

/Hans
911 3.0 SC -79

3.2 CAB · 03-09-2008, 11:36 AM

Do you have anyone that can sit in the car and hold the heat lever upward? It looks like you have already hit it with some kind of spray lube, that's great, hopefully you won't twist the little shoulder bolts off. With the rear of the car lifted and safely cradled on jack stands, you can go under it, looses the cable lock bolts, and tell the person sitting in the car the raise the heat lever as high as they can get it, and hold it there. This is being done while you are also closing the "valve" by hand, so the cable core does not pull out of its shoulder bolt. Once the heat lever is at maximum movement upwards, and the "valve" or door, is closed, tighten the shoulder bolt that holds the cable core. Then have your assistant, actuate the lever a few times while you are watching it for proper movement. If additional adjustments are needed, you can do that while you are already under the car. When I replaced my cable cores and refurbished my handbrake/heat lever, I had the car up, and being that I was replacing the cores, I had a lot of extra stainless steel cores going through the shoulder bolts. I secured the heat lever at it the top end of its movement, where it could go no further. Then I went under the car and closed by hand, the flapper gates, valves, or whatever you want to call them. I then tightened the cable core shoulder mounting bolts on both boxes, then I tested the adjustment in the cabin, then I would look at the flapper box, to make sure the movements equaled the movements that I made inside the car. Then all was well in the heater flapper box adjustment world. Hope some of this helps. Good luck!! Tony.

RWebb · RWebb's Garage

should be able to get all the way open & all the way shut
- clean up the entire area
- check vlave for sticking, rust etc. w/ cable off if need be
- lube (done?) - but lube the pivot not just the outside (need mirror to check)
- check if spring is stretched out to far, rusted, etc.
- check that the 'anchor' for the cable end is not rubbing on the sliding valve - if it is, rotate the assembly to gain clearance