I thought I could tackle this job fairly quickly, as I've replaced brushes in a motor before (RC cars/trucks, etc). Wrong. I can't seem to get the one of the brushes soldered correctly. It's the brush that attaches directly to the plastic "plate", inside the the metal sleeve that also holds one end of the copper coil. Sorry no picture, just hoping someone who's done this repair before knows what the parts look like.

I'm starting to wonder if my solder iron is not getting hot enough as it takes a long time to melt the solder (more than 10 seconds) and it doesn't seem to heat the points of contact enough, quickly enough, etc.

I also wonder if I should try a different solder with a lower melting point (lower than 425 degrees?), maybe a smaller iron tip, as the one I have is a little big but should still work...

I'm willing to take it somewhere locally, but they don't have "solder shops". Tried an audio/video repair store and the owner looked at me like I had swine flu. He said they don't "specialize" in automotive. I was tempted to ask him if he specialized in "solder", but didn't want to be a smartass. Besides I'm the one who needs help; just surprised he didn't want the business.

Anywho, any tips, tricks, ideas, places in San Diego that might be able to help? I don't think the indy mechanics will be anxious to help out...but I know more than a few. I've read the DIY here and used the kit sold by the folks up in Washington. Frustrated.

I'll even consider dropping it in the mail if someone with their
"solder-iron license" is willing to help out.

__________________
1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

I can't imagine many combinations of solder and soldering tool in which a >10sec melt time is considered normal. For the usual brand of basement workbench soldering I've seen done and done myself, it melts about as soon as you touch the tip to the material.

My first thought is run out to Radio Shack (or the local equivalent) and pick up a new iron. They're fairly cheap.

Here's my second thought. I have NEVER seen the part you're working on in person. But I'm going to take one of your verbatim statements: "It's the brush that attaches directly to the plastic "plate", inside the the metal sleeve that also holds one end of the copper coil." Are you trying to let the solder "glue" the brush to a plastic part? You sound experienced with this sort of repair, but I am not familiar with any sort of solder (that is not to say it doesn't exist) that bonds to plastic. So if that's actually what's happening then I *think* you're describing a lost cause from the start. If you're soldering metal to metal then my first suspicion would still be a soldering iron that wasn't getting hot enough.

__________________


~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL

The iron may not be high enough wattage. My unmarked pistol-type switched iron can melt MB solder, but it takes a good 15-20 seconds.

I had no problem doing mine
With a $4 iron from menards. But that 425* solder is too high. Get some electrical solder.

i see no volunteers. . . . send it to me, i'll repair and send back. no charge !

i have soldered everything from r/c cars to radiators. . .

davidh "tooldoc (at) gmail (dot) com" for shipping information.

__________________
david h
83 300D Alabama Beauty (Son's)
83 300D West Coast Rust Free that been abused

It's a lot of mass to heat up. It can take some time depending upon the temperature of your iron. I usually set mine at about 600*.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

There is a metal sleeve, err column, that the brush wire and a copper coil run through, through the plastic plate/body. Need to solder both the brush wire and copper line to the inside of this metal sleeve...

Have a 60 watt iron. Will try and find some solder that melts more quickly today and see how that works.

__________________
1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

Thanks. I may take you up on the offier.

__________________
1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

I don't have an adjustable temp solder iron, but you're probably right. My suspicion is that the copper coil and brush itself is acting as some sort of heat sink...

__________________
1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)