Cracked Firewall Repair?
Thread Starter
Rennlist Member
Joined: Jun 2001
Posts: 9,714
Likes: 10
From: Barcelona
Thread Starter
Rennlist Member
Joined: Jun 2001
Posts: 9,714
Likes: 10
From: Barcelona
Just an update on this problem.
I ended up having the Porsche Center perform the repair and the result is excellent.
It turned out taking less hours than they had anticipated, but was still 23 hours in labor, since they removed all the adjacent parts within the vicinity of the damaged firewall, welded and reinforced the cracks, and did bodywork and painted the area so that you can't tell it was repaired.
The only parts replaced were the clutch master cylinder, which I had already bought, plus the clutch pedal bushings and spring as a "while you're in there." The clutch pedal feels very different now -much more solid and springy. I have to keep the seat a bit farther away from the pedal assembly than before.
The repair tech explained that as they began uncovering the firewall from both sides, they found a whole "spiderweb" of cracks that they welded individually and reinforced with very thin sheetmetal. The Porsche Center took photos during the repair process which I hope to obtain from them and post on this thread for future reference.
Total repair bill was € 1,774. I know it was a lot of money but the car is a relatively rare model, I've had it for 8 years, it's in great condition and I plan to keep it, so it was something I had to do.
I want to thank all those who replied to this thread and sent me emails with pics and instructions on how they repaired their cracked firewall. You guys gave me the motivation to get this done and continue to enjoy my favorite car. Thanks!
I ended up having the Porsche Center perform the repair and the result is excellent.
It turned out taking less hours than they had anticipated, but was still 23 hours in labor, since they removed all the adjacent parts within the vicinity of the damaged firewall, welded and reinforced the cracks, and did bodywork and painted the area so that you can't tell it was repaired.
The only parts replaced were the clutch master cylinder, which I had already bought, plus the clutch pedal bushings and spring as a "while you're in there." The clutch pedal feels very different now -much more solid and springy. I have to keep the seat a bit farther away from the pedal assembly than before.
The repair tech explained that as they began uncovering the firewall from both sides, they found a whole "spiderweb" of cracks that they welded individually and reinforced with very thin sheetmetal. The Porsche Center took photos during the repair process which I hope to obtain from them and post on this thread for future reference.
Total repair bill was € 1,774. I know it was a lot of money but the car is a relatively rare model, I've had it for 8 years, it's in great condition and I plan to keep it, so it was something I had to do.
I want to thank all those who replied to this thread and sent me emails with pics and instructions on how they repaired their cracked firewall. You guys gave me the motivation to get this done and continue to enjoy my favorite car. Thanks!
Nordschleife Master
Joined: Oct 2002
Posts: 8,985
Likes: 3
From: Vancouver BC
I just finished the job myself last weekend.
On the 968, the entire intake manifold had to come out, and then the brake booster, clutch master, and associated crap had to come out of the way.
Once I got everything out of the way, I cleared out the insulation from behind the firewall. Pretty much had to permanently remove some of it, as it is really hard to get in there.
I also disconnected pretty much everything electrical just in case, because the heat generated during welding could travel up the wires and melt them, and then cause short circuits. (note; most importantly: remember to disconnect all the GROUND wires, as they touch the firewall where lots of heat will be travelling.
Anyways, I tack welded the wall shut (less warping if you tack it before shooting a bead right away)
Then I fabbed a small triangle bracket that would brace the wall against the fender.
Then I bead/seam welded the whole thing. My weld were honestly pretty ****ty, due mostly to inexperience, uncleaned surfaces, and really really awkward angles. Once it was welded, I slopped gooey expoy all over the welds to seal them airtight.
Sprayed it with primer, and then some metallic blue to match the car's paint.
Put everything back, bled everything, etc etc etc. Clutch feels fine now!
Afterwards, I had a bunch of eletrical problems, probably as a result of the work. A battery cable was loose and caused my car to die, I had to reset the airbag light again, my wipers stopped working, and the rear defrost fuse blew. Kind of random... but anyways the car runs awesome now.
Pics should come up as attatchments.
On the 968, the entire intake manifold had to come out, and then the brake booster, clutch master, and associated crap had to come out of the way.
Once I got everything out of the way, I cleared out the insulation from behind the firewall. Pretty much had to permanently remove some of it, as it is really hard to get in there.
I also disconnected pretty much everything electrical just in case, because the heat generated during welding could travel up the wires and melt them, and then cause short circuits. (note; most importantly: remember to disconnect all the GROUND wires, as they touch the firewall where lots of heat will be travelling.
Anyways, I tack welded the wall shut (less warping if you tack it before shooting a bead right away)
Then I fabbed a small triangle bracket that would brace the wall against the fender.
Then I bead/seam welded the whole thing. My weld were honestly pretty ****ty, due mostly to inexperience, uncleaned surfaces, and really really awkward angles. Once it was welded, I slopped gooey expoy all over the welds to seal them airtight.
Sprayed it with primer, and then some metallic blue to match the car's paint.
Put everything back, bled everything, etc etc etc. Clutch feels fine now!
Afterwards, I had a bunch of eletrical problems, probably as a result of the work. A battery cable was loose and caused my car to die, I had to reset the airbag light again, my wipers stopped working, and the rear defrost fuse blew. Kind of random... but anyways the car runs awesome now.
Pics should come up as attatchments.
Rennlist Member
Joined: Jul 2001
Posts: 2,120
Likes: 4
From: Brisbane, Australia (Formerly: Sunnyvale, CA)
Thread Starter
Rennlist Member
Joined: Jun 2001
Posts: 9,714
Likes: 10
From: Barcelona
Ok, blast from the past but at 167K my S2 has developed a cracked firewall at the clutch master cylinder. This is my third 944 with this problem. Aargh! 
Wish the factory would come out with a repair kit or something, since this appears to be endemic with the 944.
Wish the factory would come out with a repair kit or something, since this appears to be endemic with the 944.
Burning Brakes
Joined: Dec 2006
Posts: 871
Likes: 4
I think it was mentioned in this post earlier, a less expensive option is an L bracket bolted to the MC and firewall. The bracket lightened up my pedal and the MC barely moves at all when the pedal is depressed.
Racer
Joined: Dec 2011
Posts: 339
Likes: 91
From: Talca, Chile
My firewall had cracked as well. This is the repair a previous owner had done. A bit ugly but, I doubt there will be any flex now.
http://www.flickr.com/photos/23465100@N00/7721642544/http://www.flickr.com/photos/23465100@N00/7721642544/ by http://www.flickr.com/people/23465100@N00/, on Flickr
http://www.flickr.com/photos/23465100@N00/7721642544/http://www.flickr.com/photos/23465100@N00/7721642544/ by http://www.flickr.com/people/23465100@N00/, on Flickr
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Burning Brakes
Joined: Nov 2007
Posts: 872
Likes: 0
From: Nuke City, NM
I had this problem as well. Since my car is a v8 swap i actually have it a little worse than you all, since i use a 7/8" master. As it would happen my brake master is out right now while i switch to hydroboost, so i was able to actually get a picture of my solution!
The first thing i tried was welding a wedge that oriented the master vertically. That helped a lot but i was still getting a millimeter of flex.
My ultimate solution (which i think is also a very easy solution, especially to those who don't want to weld on their firewall) was to take a strip of 1" wide metal and make a "P" shape out of it. I then slid the loop of the P over the master cylinder and bolted the leg to the fender below it. Zero flex!
While i'm on the subject, i found that the CNC brand of master cylinders are an okay fit for these cars. I had to massage the shock tower a small amount and use a 90* line adapter, but no big deal. Previously i had tried Wilwood and Tilton stubby master cylinders (failed very quickly). The full-size masters from both Wilwood and Tilton will not fit with any amount of pounding.
The first thing i tried was welding a wedge that oriented the master vertically. That helped a lot but i was still getting a millimeter of flex.
My ultimate solution (which i think is also a very easy solution, especially to those who don't want to weld on their firewall) was to take a strip of 1" wide metal and make a "P" shape out of it. I then slid the loop of the P over the master cylinder and bolted the leg to the fender below it. Zero flex!
While i'm on the subject, i found that the CNC brand of master cylinders are an okay fit for these cars. I had to massage the shock tower a small amount and use a 90* line adapter, but no big deal. Previously i had tried Wilwood and Tilton stubby master cylinders (failed very quickly). The full-size masters from both Wilwood and Tilton will not fit with any amount of pounding.
