"my tool box includes Fluid Film spray."

I was just about to post that... there are some good threads in the archives about that stuff.... my Ford Tractor dealer carries it.... it is lanolin ( sheep oil ) based.

Just so happens I've got a Ford tractor It's New Holland's 1720 3 cylinder DIESEL!

phosphoric acid. I've had very good results with that stuff.

about $10 for a gallon jug at most home improvement stores.

Sometimes I use an air compressor and spray gun. I stick the hose into the bottle and spray away....under the weel wells, under carriage, floor boards, trunk wells, etc.

be carefull not to get it on your exterior paint work, it will stain.

__________________
1987 300TDT
1981 VW MKI Caddy 1.6 diesel, waiting on engine swap
1983 D-50 Power Ram 4x4 "Mitsubishi" 2.3 turbo diesel
assorted gas powered crap and motorcycles

RIP: 1984 300TDT, 1982 300TDT, 1984 190D 2.2, 1992 300D 2.5, 1987 300TDT, 1982 Maxima LD28, 1983 Maxima LD28, Isuzu C223 P'ups X3, 1983 Holiday Rambler 6.2 Banks turbo diesel, 1984 Winnebago LeSharo 2.1 TD, 1985 Allegro 6.5

My prime concern is where the rust is progressing out of sight. Like inside the rocker panels. That also influemces the jack points as well. I always mix up a batch of grease and oil and spray it in 1/2" holes using the available undercoat plugs to seal the holes. The rockers panels are 14 gauge steel i believe. This i do after the required body work is completed and painted as to do the body work later the cleanup would be nearly impossible. The oil and grease creep around in there and reduce oxidation rate to just about nothing. Same mixture into any subframes etc that i can get into. Live in very harsh rustbelt area to start with. Still own a hydralic grease and graphite gun that was required to treat cars years ago. Unfortunatly the large barrels of product are no longer available. Just had to make sure no future work in any area applied as to do it later would required steam cleaning. My old cars were the last ones of their type on the road when used year round and some were still in pretty good shape bodywise. Surface rust on mercedes always has looked like primarily primer/paint adhesion problems or water creep underneath. Seems like non waterproof original primer was used. Starting from an unprotected point like window lip that paint was scrapped off or by trim clip hole. Like to get back to primary clean metal and go from there myself. That way know for sure rust is not going to come back at those locations. Just my beliefs.

I've used Rust Bullet on a very small area that started due to a plugged trunk drain. Got to both sides of that one so I'm golden. Also used it underneath my battery tray and on the tray itself, and on some surface rust in the engine compartment sunroof drains(which were plugged up too). The car was taken care of, just the drains were ignored since not everybody has the inside scoop on this stuff. The Rust Bullet is good to use for tight hidden areas, you only have to knock the loose rust off and paint a couple of coats on it and you're done.
I recently bought some jack hole plugs. My jack points are rust free, and what I did was pressure wash them out, roll up one of those blue paper towels, run it up into the holes to get the excess dirt/water out, roll up another one(I'm good at rolling things)slather some wheel bearing grease on that one and run it up in there, just to put a light coating inside, put some grease on the end of the plugs and plug 'em. I'll never use those jack points most likely.
Regarding the Fluid Film Spray; I understand that it's good to spray it inside the rockers. What do I remove to access the inside of the rockers? I see there is a cover of some sort at the rear of the front wheel wells- how does this come off? Someone do post a list of the likely places on w123s that could benefit from a liberal application of Fluid Film Spray.

__________________
'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)

buy a southwest car and move to the sun shine state and stay out of SALT and clean it a lot,i have used por15 great stuff. Dennis

Think person is speaking of plastic inner well mud flap. Retained by several screws. Front end of actual rocker panel is capped with metal. I drill access holes along bottom of rockers and spray in there. In fact if I remember some of mine were already drilled with plugs. But this may be where aftermarket applied rustproofing job was previously done. Cannot think of any other access to internal area of rockers.

Very glad I started this thread.
Much good information, between hijacks.

all of the abover are surely true. the most important thing on an older benz is caulking the front and rear windwhield with black silicone to keep water out of the body areas not designed to deal with water. simple easy doesnt take too long. you need to clean the area really well first with some kind of cleaner such as alcohol let it dry then run a small bead between the glass and rubber.

if this is not done, you get a rusty floor which may not be known until the seat starts to fall through, and rust above the wheel opening in back and the bottom of the trunk on each side.

happy benzing.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

"the most important thing on an older benz is caulking the front and rear windwhield with black silicone to keep water out of the body areas not designed to deal with water."

Please don't do this! Silicone absorbs water and will cause rust around your windows!

The correct thing is butyl rubber sealant, any auto glass shop can reseal your windows for you.

R Leo,

Actually I live where road salt is used liberally, Northern PA. I just don't use the good MB in the winter, I have a beater MB for the winter. Bought it as a parts car 6 years ago and it is still going 65,000 miles later.

P E H

Actually pulling the rear windsheild and installing a new gasket while taking care of any rust is the proper way to go about this.

Same goes for the front.

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

sure changing the gasket is good but expensive and the shop will not guarantee not to break the windshield. also i have found that even after a new windshield is installed sometimes the seal leaks and caulking is still in order.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Gasket cost me $80+$30 for the MB sealant. The rear windsheild can be done in your driveway in about a day, depending on if you find rust. For the rear windsheild you need to chaulk the gasket in order to get it to seal. In the manual they give you the part # for the chaulk.

The W126 at least does not have a gasket up front, a seal is made with the sealent that is used. If you have glass coverage your insurance company will probably cover the windsheild if it is pitted. When I had mine done the guy said if it leaks bring it right back and he will fix it.

My concern with running a bead around the rear window is that water will probably get behind it causing more rust. That is already a rust prone area on these cars.

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

i used to caulk both sides of the gasket. i now only caulk the glass/ gasket side. i dont think the rubber/ body side actually leaks, ordinarily.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.