jaje

I did a search but couldn't find anything. In progress of replacing the Master cylinder I noticed a crack in the firewall (wavy line underneath the hole for MC is the crack - first 3 pics are from engine bay side and the last from interior side under the dash). It looks like someone tried JB Weld at one point and I pounded the firewall to make if flush. Has anyone had this problem...looks like fatigue stress. How did they get it fixed? I'm wondering if I should have a proper shop reinforce the area and do a better weld job than I can do with my flux welder.






Also on a side note...what is this apparatus in the very middle of the picture. It connects to the intake manifold and the wires run into the engine wiring harness. I have no idea what it is. The car is a very early 1983 (1982 mfg date) US 944.

Legoland951

Its common for early 944s to have the CLUTCH master firewall break off. I have fixed 5 of them so far. Welding is difficult as its hard to get in there. The best way is to cut a sheet metal or aluminum much larger than the area affected and bolt the plate on top of the firewall. Silicone the piece but make sure you cut the hole in the right location.

V2Rocket

is this a possible cause for a squeaking clutch pedal? whether the car is on or off when i push the clutch i get a weird metallic squeaking kinda noise. my dad said it was the throwout bearing any ideas?

Luis de Prat

BTDT. In my case, the brake master cylinder came off and a 1/4" steel plate with the necessary holes was pop riveted to the firewall.

Only issue was to adjust the clutch master cylinder rod (filing it down) to keep it from binding against the new firewall thickness.

jaje

Thanks - me and a friend were thinking of adding more sheet metal but we were worried of not enough thread to get a secure hold on the master cylinder and the fact that it changes the mounting location.

nkgosselin

You can easily fix with just a support bracket. I detailed this at my blog...

http://kevingosselin.blogspot.com/20...-bearings.html

jaje

Thanks Kevin..I was just reading your blog post on this. There looks to be 3 ways people have fixed this.

porshhhh951

Yes its common. My car had the same failure. I didn't even ask what method was used to fix it though. He may have just welded in a new sheet over it.

Legoland951

The brake master sits on the booster and I have never seen that come off. I am talking about the clutch.

Luis de Prat

Maybe there was just one hole, then, but the steel plate was machined with the necessary hole(s) to fit over the firewall and reinstall everything.

Mike C.

Here are some ideas: https://rennlist.com/forums/924-931-...ix-images.html

DarylJ

Considering a firewall crack and the throwout bearing are in totally different places, it would seem fairly easy to figure out which it is.

Have you even bothered to open the hood and have someone else depress the clutch with your head near the master?

viperbob

This happens a lot. We try to weld the area if accessible, and then weld a small plate over that.