911 SC Climate Control Bowden Cables

gazzerr · 05-25-2015, 08:19 PM

Hi Guys,

82 SC. I am having an issue with my climate control frunk flapper control bowden cables.

The middle lever will pull just fine (move to the right), but won't push (move back to the left). The lever feels spongy and will "bounce" back to the middle position. The only way you can get the lever to travel back to the left is to reach into the trunk and pull the cable back down on the footwell flapper valve lever. I've tried adjusting the clip and pinch bolt about a dozen times with no luck. I assume it's binding up somewhere. I have all the bowden clips holding the cable sheath in the correct position.

If I crawl up under the dash I did notice the cable is *slightly* bent (it's not dead straight) coming from the control panel lever into the black cable sheath. Would this cause it? Assuming I can remove the climate panel from the dash is it possible to remove the cable from the lever (assume massive PITA) and straighten it?

Thanks. G.

bugstrider · bugstrider's Garage

G,

Having just replaced my entire control head with cables I might suggest getting into the trunk area, pulling the cover panel and check your cable connections there. You might have a gunked up flapper valve or a cable securement issue on the far end.

Either way, it will allow you to at least inspect and lube the solid cables. You can also check the point where they pass through from the passenger compartment and into the trunk for binding.

Good luck
T

uwanna · 06:15 AM

Quote:

Originally Posted by gazzerr

Hi Guys,

82 SC. I am having an issue with my climate control frunk flapper control bowden cables.

The middle lever will pull just fine (move to the right), but won't push (move back to the left). The lever feels spongy and will "bounce" back to the middle position. The only way you can get the lever to travel back to the left is to reach into the trunk and pull the cable back down on the footwell flapper valve lever. I've tried adjusting the clip and pinch bolt about a dozen times with no luck. I assume it's binding up somewhere. I have all the bowden clips holding the cable sheath in the correct position.

If I crawl up under the dash I did notice the cable is *slightly* bent (it's not dead straight) coming from the control panel lever into the black cable sheath. Would this cause it? Assuming I can remove the climate panel from the dash is it possible to remove the cable from the lever (assume massive PITA) and straighten it?

Thanks. G.

I feel your pain! I have had EXACTLY the same problem for years. I have disconnected/reconnected many times while trying to straiten the cable path (even though it doesn't look bent), adjusted at flapper end, and on and on. Result NADA! The funny thing is, when disconnected from the flapper, the cable runs as
smooth and free as can be!
I'm a pretty good mechanic, but it has me stumped. Whats strange is, the other two cables work flawlessly!
I have acquired a like new replacement lever panel/cable assembly, and just haven't gotten around to installing it yet. I'll watch this thread for your solution to this damned frustrating nit problem! LOL

gazzerr · 05-26-2015, 04:46 PM

Thanks for the advice Guys. Yes when it's all disconnected mine operates smooth and free too so the more I think about it, the more I think it's the slight kink between the end of the cable cover and the connection to the dash lever. I'll try to straighten it in the next day or so and report back. G.

gazzerr · 05:45 PM

OK so I fixed it. Bugstrider you were right. The secret (at least in my case) is that there has to be enough adjustment available in the cables so that the flappers that they are connected to in the air distribution boxes are perfectly synchronized so they can open all the way and close all the way together. If they aren't synchronized one will open or close all the way first, the cable will run out of travel and the dash lever will bind along it's travel. I removed the big inner hose off each box so I could see the flappers operating. One of my cables had a right angle bend it where it went through the pinch bolt. This meant that the cable could not be adjusted properly. I straightened it.

You have to loosen up the pinch bolts on the distribution box "L" levers and then move the dash levers all the way to the left being careful that the cables don't come out of the bolt hole (PITA to put back trust me - the bowden clips are even worse - that was a battle). Make sure all the air flappers are at the end of their travel for the dash lever's left position (you can watch what the cables want to do and easily work out what position they should be in). I then tightened the pinch bolts. I found I had to loosen and retighten the cable bolts to the passenger distribution boxes to remove any residual cable tension once I had the driver's side adjusted properly.

All my levers now work well right through their travel. The fan (top) and (heat) side are like butter. The cold side is still a *little* tight but it works well. I think that whole mechanism needs a bit more lube.

Hope that helps.

G.

KerryChadderton · 08-17-2016, 04:06 AM

Reviving an old thread here, but I thought I'd give it a try.

My symptoms are exactly as described and I'm going on 12 hours of this insanity. However adjusting does not help as it did with gazzerrs.

I'm looking for new, replacement Bowdens. A rennlister suggested a cycle shop. It's a good idea.

Bugstrider, were you able to get new Bowdens when you fixed your climate control?

gazzerr · 08-17-2016, 06:14 PM

Hi Kerry,

Yes it's a frustrating job. If the cables move freely from the levers in the dash when they are disconnected you probably don't need new cables.

You need to pull the tops off the flapper boxes so you can watch them move perfectly synchronized across the full range of travel. If they are even a little bit off the whole thing binds up. It took me many many tries to get it right.

G.

KerryChadderton · 08-19-2016, 07:02 AM

Thanks Gazzerr. I'm going to take your advice. I paid close attention to movement, but not synchronization. I did find new Bowdens though. The Porsche dealership of all places. $14.00 a piece! Between your experience and new cables I should be successful. Thanks again!

gazzerr · 08-19-2016, 09:54 AM

Cool good luck. Yeah they have to be synchronized all the way. If you take the top off the flappers you can watch it. Watch out for those clips that hold on the tops they can spring off like a bullet.

I think the toughest part is replacing them at the dash console. Let me know how you got on with that.

It's amazing what you can find at the local Porsche dealer of all places. Agreed.

Beer helps!

.