560SL Cowl Drainage & Leak

[ctaylor738]

Today I went after the last cowl leak in the 560SL, which causes a small amount of water to collect on the corner of the heel pad on the driver's side floor. I pulled the under-dash cover off and discovered that the water was getting in around the grommet that holds the hood release cable where it goes through the firewall. Looking under the hood, I discovered rust around the grommet and generally in the area including the grommet where the vacuum lines go through. Ugly.

What seems to be happening is that water from the corner of the hood and the forward edge of the cowl grille is collecting in the little channel under hood hinge, then running down the underside of the little channel, then down to the grommets.

My question is - where is this water supposed to go? It can't get to the drain further back that handles the windshield because there is a very official looking bead of sealant blocking the channel. There appears to be no place for it to drain, so it would end up causing more rust under the brake booster.

What am I missing?

[page62]

I saw that area in my car this evening as I was vacuuming out the Live Oak leaves (courtesy of the previous owner).

Probably the best thing is to paint the metal with some Rust Bullet (or one of its cousins), and seal up any potential water intakes with a goodly amount of silicone seal. Then, even if you get standing water it's just going to sit there and cause no harm!