Hood hinge drain rust repair - PeachParts Mercedes-Benz Forum

Chad300tdt · #1 08-25-2008, 09:42 PM

So I was washing my wagon on Sunday afternoon and saw water in my interior AGAIN!! I thought I had all the leaks addressed and now I have another one.

Anyway, I tracked it down to the driver side hood hinge area. I treated the upper drain after taking out the hood spring for easier access ... it still leaked.

I remembered reading a post about the screws that hold the wheel well liner in place being an entry point for water, so I removed the liner. It was loaded up with dirt and I found a surprise that I've been dealing with since.

Just below the lower drain opening was a hole at the back of the emergency brake pedal assembly.

Here it is with the e-brake pedal removed. It's all wet with Metal Ready to neutralize the rust:

Here's the rest of the floor after I removed that sound deadener crap that hides rust:

I cleaned everything up carefully, treated with POR-15 and shaped some sheet metal. I then buttered the back of the sheet metal patch with JB Weld and pop riveted it in place. You can see there was a second hole a littler lower that I patched with sheet metal as well.

After the JB Weld set up, I filled the edges of the patch with more JB Weld.

I also filled the wheel well side of the patch with JB Weld.

Tomorrow I will coat everything again with POR-15, drill the bottom hole for the e-brake pedal, put everything back together, lay some dynamat back where I removed the original sound deadener, Under coat the wheel well and be back on the road with a leak free wagon AGAIN.

I'll post more pics after I finish the job tomorrow.

JimmyL · #2 08-25-2008, 09:57 PM

That wagon keeps trying to rust right out from underneath you. You have really been proactive with all your repair work. Nice job Chad!
Now hopefully you will have more time to devote to Photoshop.....

Chad300tdt · #3 08-25-2008, 10:03 PM

Thanks Jimmy, I've been trying to get around to Whiskeyman with an apron, but my rust crusade had me tied up.

I'm going to pull the wheel well liner on the passenger side tomorrow too. I hope there aren't any surprises waiting in there. :fingerscrossed:

I need to make pulling those liners to clean out behind them a part of regular maintenance. Once dirt gets trapped in an area where moisture travels, it promotes accelerated rotting.

OldPokey · #4 08-25-2008, 10:30 PM

I think I'll peel back the liner on my TD this weekend too - I have a patch to put in just under the driver side door anyway...

Whiskeydan · #5 08-26-2008, 01:17 AM

Chad can fix/make/do anything with JBWeld.

I discovered it has metal particals in it. This last weekend I had the bright idea of 'JB Welding' a magnet to the differential drain plug. I thought it would attract and hold any worn metal floating around in there.

Bad idea! The magnet revealed the metal particals in the JBWeld. I decided not to place those in the diff.

Chad300tdt · #6 08-26-2008, 10:16 AM

Quote:

Originally Posted by Whiskeydan

Chad can fix/make/do anything with JBWeld.

I discovered it has metal particals in it. This last weekend I had the bright idea of 'JB Welding' a magnet to the differential drain plug. I thought it would attract and hold any worn metal floating around in there.

Bad idea! The magnet revealed the metal particals in the JBWeld. I decided not to place those in the diff.

How did the JB Weld react to the magnet? Can you take a pic? Maybe I'll have to experiment when I have some free time.

Maybe my superhero alter ego can be "Epoxy Man, Rust Crusader".

Mike D · #7 08-26-2008, 10:31 AM

The POR15 filler works well also. I use it instead of the JB-weld for bodywork-panel repair. I find the JB-weld to be harder to work. It's still the best stuff for bonding pieces together but what a pain to work smooth.

I like the POR15 because; A: it's water based so clean-up is a breeze, B: it can be worked with your fingers to a smooth, feathered surface, C: sands soooo much easier, D: accepts paint more consistently than the JB-weld, E: it cures in 1 hour with a working time of 20-30 minutes (depending on the temperature).

I use the JB-weld on floor panels, structural and hidden areas.

Chad300tdt · #8 08-26-2008, 10:36 AM

I'll have to try the POR-15 filler. I've used all their other products including the putty. I've been very happy with the results and durability of POR products. The curing time of 1 hour for POR filler vs. 24 hours for JB Weld is very attractive too.

The trick with JB Weld is to mix it and let it sit for about 30-40 minutes before spreading it like a body filler. Once it thickens up, it's not too bad to work with. Plus it cleans up with soap and water too.

The pics above show the JB Weld as a drippy mess, because I don't care how it looks under the Dynamat and in the wheel well beneath the undercoating.

I used the same technique on my quarter window and quarter panel and they came out very nice.

charmalu · #9 08-26-2008, 11:39 AM

Chad, think you would be smart to pull the fender off. you might be surprised to find rust back in that corner. my 85 had rust ( not like yours) on the wall behind the fender and starting in the end of the rocker. MB does not coat the wall very well. also saw this on another 85 at PNP that I pulled off a fender.

also on the splash shield there is that drain tube molded in. well it is not open on the end and will trap dirt etc... I took a knife and cut the bottom out to open it up. do both sides. those hinge pockets seem to be a forgotten area to maintain on these cars.

With the Por-15, I also use their Marine Clean to clean off any oil etc.. before I start my project. one of the best cleaners I have ever used. the stuff will actually disolve tar, asphalt. don`t use it on your asphalt driveway, I use it (diluted down of course) to spray on my wheels when I wash them. even though I wash down the drive way, I can see it has been slowly eroding away the oils. can be diluted down to 10%.
don`t spray on aluminium wheels will spot them, but a great cleaner.

also use the metal ready to etch the metal and will eat away the rust if left on long enough. then coat with the Por paint. also use the Por in a tube for a sealer, use an acid brush to work it in. when I don`t want to open a can I use the sealer for small areas.

Charlie

Chad300tdt · #10 08-26-2008, 12:26 PM

Hey Charlie,

I know what you're talking about with the rust under the fender. I was actually able to see behind there pretty easily without removing the fender and treated it with a long handled brush. There was a ton of dirt trapped at the bottom of the fender too. It had clogged up the drains there. All is good now. I just drilled the bottom bolt hole for the e-brake pedal and coated everything one last time with POR-15. I'm just waiting for it all to cure so I can put everything back together.

Also, I'm a "POR-15 System" user and won't skip ANY of the steps. The whole system is what makes this stuff work SO well.

Thanks for the tip about the drain tube in the wheel well liner. I'll be trimming the bottom out of mine as well.

SwampYankee · #11 08-26-2008, 04:19 PM

Chad, the more you dig the more afraid I am to open my Pandora's box of a TD.

Your How-To's and step-by-step photos are great references to see how everything comes apart.

Chad300tdt · #12 08-26-2008, 05:11 PM

Thanks Swamp.

Here's the continuation:

Here's a view of the "fixed" lower hood hinge drain from inside the engine bay. You can see the hole for the upper stud on the E-brake pedal just above and to the left of the drain hole:

Here are the holes for the E-Brake pedal. I drilled the lower one in the patch.

Then I coated everything with POR-15 again and re-installed the E-Brake Pedal.

This is the view of the wheel Well with the E-Brake re-installed. I cut rubber washers that I put on the studs of the E-Brake Pedal to seal against the firewall and used sealant on the wheel well side:

Here is the hollow behind the fender where I treated some additional rust:

Dynamat installed:

Undercoated:

Here's the wheel well liner before and after I cut the drain tube bottom out. Thanks for the tip Charlie.

Wheel well liner installed:

Inside done and leak-free:

Back on the road. BRING ON THE RAIN!!!

Mike D · #13 08-27-2008, 08:03 AM

Looking good! How does the Dyno-matting hold up under wear? Foot pressure not direct abrasion. I've thought about using it but it's pretty pricey. I know it works fine on the firewall and under the rear seat.

What are you using for the undercoating?

Chad300tdt · #14 08-27-2008, 09:23 AM

Quote:

Originally Posted by Mike D

Looking good! How does the Dyno-matting hold up under wear? Foot pressure not direct abrasion. I've thought about using it but it's pretty pricey. I know it works fine on the firewall and under the rear seat.

What are you using for the undercoating?

Thanks.

I haven't used Dynamat before, but I think it will be OK since it's under the carpet and I also put the rubber cover back over it on the firewall. I don't think it will get much direct pressure. As I was applying it it seemed like the only thing that would be bad would be pressure in a small spot that could puncture the foil layer. I bought 2 kits that had about 1.4 square feet per kit. It cost me about $44. I think it works slightly better than the original sound deadener and it's surprisingly thin.

As far as undercoating, I'm using Duplicolor Rubberized Undercoating. I've used it for years on a number of the cars I've owned and it holds up nicely. The pics above show it glossy because it hadn't dried completely. Once it's dry it looks more flat black. The can says you can paint over it too, but I like to leave it bare so I can reapply it before winter as needed.

Mike D · #15 08-27-2008, 10:33 AM

Quote:

Originally Posted by Chad300tdt

Thanks.

I haven't used Dynamat before, but I think it will be OK since it's under the carpet and I also put the rubber cover back over it on the firewall. I don't think it will get much direct pressure. As I was applying it it seemed like the only thing that would be bad would be pressure in a small spot that could puncture the foil layer.

Yup, that's what I wondering about. I was thinking of putting it under the front footwells but I guess I'll pass and keep using tarpaper. I tried using roofing shingles cut to fit but they are abrasive and tend to eat up the rubber backing on the carpets.