I am trying to clean an old Marklin DB streamline 4-6-2. The loco has a lift up side plate that reveals what I assume are brush caps. I need to somehow remove these brush caps which are slotted to remove the chassis from the loco.
No, and I wouldn't do it if I were you. Too many li'l bits to get lost, and it's a PITA to reassemble these locos with motors integrated into the chassis. You should be able to remove the body shell, so that you have the chassis and power train accessible. That is often enough: put AeroCar's contact cleaner + lubricant on every bearing, and run the loco. That usually does the trick. Relube with oils and greases on wheel bearings and gears - but as little lube as possible, a pinhead's worth is usually enough.
If that's not enough, clean the chassis in methyl and isopropyl alcohols. That's the method I use. Use a mixing bowl big enough to immerse the engine, pour in the methyl, clip leads to the motor and/or chassis and/or pickups, immerse the engine, and turn on the power. Let it run a while. You should see muck and guck emerging from the engine. Turn off the motor, and remove. Let air dry, and repeat with isopropyl. After air drying, oil and grease using Labelle or AeroCar lubricants (they come in bottles with hypo-style tubes attached.)
This method is quite safe, as the alcohol cannot ignite while the engine is immersed: there is no available oxygen. The brief run after removal from the bowl won't ignite the alcohols either, as they are evaporating, which makes them cold and won't reach ignition temperature. But just to feel safe, do the cleaning in the open, or somewhere far removed from combustibles.
Good luck. It's not easy cleaning old locos. Often, the cleaning reveals other problems, too. Sigh.
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