Well has promised I got to do the rear main on the Bronco today. To highlight the details real qucik. My son and I replaced the timing chain about 3 months ago, and before I could inform him that it might be a good idea to place a few towels inside the opening of the oil pan he droped a socket in there. Has luck would be, we had to yank the pain to get the socket back.

I am a frim believer in the merits of RTV, keeping a stock pile of blue, black and copper in the garage at all times. As such when it came time to reinstall the oil pan I just RTV'd it up with the black. The only sign of leaking after driving almost 1500 miles was from the rear main so I guess the RTV wasn't a bad choise over installing a gasket.

When I use RTV I apply it in the same manor as panel glue. I make sure both surfaces are thoroughly clean, using a wire brush and brake cleaner with a lint free cloth. I'll the apply a coating to one side and then let that skin for about 10 minutes. Next I fit both pieces together and press them tight. I'll let them set for only about 1 minute and then pull them apart. This leaves a layer of RTV on both pieces that I let skin again for about 10 minutes. After the second rond of skinning I'll bolt it together and forget about it. I learned the hard way never to pull off excessive RTV (it tears the inside surface and starts leaks) but to use a razor to clean up any overhang.

All this nice perp-work and taking my time sucks though when I have to pull something apart. Tonight was a good example. As we tried to get the pan off the RTV set to almost a glue like hold. It took a couple of screw drivers and a couple of wooden door shims to pry it down and out. But this made for a good test of the ideas to remove the RTV residue that were posted on here.

I know that I could have just used a putty knife and sharp scrapper but wth.

#1 Was the Ammonia. Cheap .89 local store brand. Has many guessed this stuff is hard on the throat and eyes, but it worked great. After about 5 minutes it was peeling and bubbling the RTV off the metal. When I wiped it off it left no traces behind. Besure you are in a well ventilated area and to use rubber gloves. This stuff with burn the hell out of any cuts you may have. It ate threw the fresh silicone real nicely to. Making cleanup easy.

#2 WD-40 My wife says it will remove cranoons from wall without hurting the paint. That might be true but it didn't have an effect on RTV black that was dried though it did do a good job of fresh cleanup.

#3 I didn't try the oil in plastic scraper. Figured that was only for removing glue and such.

#4 Was a heat gun. That was a mistake. Smoke everywhere and that popping sound the pan made about gave me a stroke. Ok figured that was to much heat so got out the daughters hair drier. I figured she wouldn't mind as much as the wife if I used it in the name of science. Besides it's her birthday in a couple of weeks and now I know what to get her. The hair dryer did ok but took longer and still had to scrape some of the tougher stuff off.

#5 Was the Menards brand silicone remover. I assume this is the same stuff or something like that Home Depot sells. The guy behind the counter didn't think it would do all the best because silicone used on tubs and showers doesn't have as strong as adhession has RTV. It didn't work at all while trying to remove dried silicone, and did only a fair job of cleaning up fresh silicone.


For the effort and the way it worked on hard and fresh silicone I would recommed using the ammonia. If you can't handle the smell did a combo of the other 3 should do the job.