Replacing the brushes on a 116 blower motor - PeachParts Mercedes-Benz Forum

kerry · #1 02-04-2009, 01:10 PM

The blower motor on my 116 became inoperative in cold weather. I replaced it with a junkyard blower but wanted to see if the brushes are replaceable since the blower motor and squirrel cage are pretty pricey at $1150. The 116 blower is different than the 123 blower. Initially I thought the back plate was held in place by cast in 'ears' on the housing. I was wrong. After cutting off a couple of ears with a dremel tool, it appears that the back plate is only held in place with epoxy. Cutting off the ears allowed me to pry off the back plate but in retrospect, I think it could have been done with the ears in place. I'll be attaching some pictures so people can see it. I haven't sourced brushes yet but the ones on mine were pretty worn down. The inside of the motor was filthy. I believe this is a result of the rubber tube that connects the inside of the motor with the duct work in the car. All that dirt was probably not helping the situation in the motor.

kerry · #2 02-04-2009, 01:17 PM

Here are some pictures. Sorry, I did not realize some were not in exact focus.

kerry · #3 02-04-2009, 01:19 PM

More pictures.

compress ignite · #4 02-04-2009, 04:53 PM

Persistence wins out.

bgkast · #5 02-04-2009, 04:58 PM

The brush assembly looks similar to the the W123.

What kind of brushes did you use?

kerry · #6 02-04-2009, 06:11 PM

I haven't sourced the brushes yet. None of the brushes at Ace Hardware fit. I think I need metric sized brushes. I also need brushes on which the wire exits the spring at the end of the brush and is not connected to the washer at the end of the spring.

KAdams4458 · #7 02-04-2009, 06:56 PM

I've dealt with a few odd brushes before. It's slightly insane and definitely time consuming, but I have been able to make oversized brushes fit in to smaller places by carefully filing them down to size.

You can also check McMaster-Carr, one of my favourite online companies ever.

kerry · #8 02-09-2009, 10:11 PM

OK, I ended up doing what Jimmy did on one of his blowers. I bought the biggest brushes at Ace Hardware,($8.73 each) cut off the button at the end of the wire, threw away the spring and cut them down to size with a miniature hacksaw and some sandpaper. Soldered them back in, test ran it and it seems to run fine. I have yet to reattach the back cover. I'll have to at least use epoxy like the OE system. That could be the tough part. I'm having a little trouble getting it to seat far enough on the shaft but I'll mess with that later.
Right now it looks like the brushes are indeed replaceable on the 116 blower motor.

kerry · #9 02-11-2009, 01:07 PM

Seating the back plate was just a matter of getting the stiff wire in the right location.
I first fixed the bakelite panel that holds the brushes in place with 5 minute epoxy. Once that had dried, I fixed the metal back plate in place with 5 minute epoxy. It seems to function fine.

It's worth noting that I did not completely disassemble the motor and remove the armature. I didn't because that would require removing the squirrel cage from the shaft and another member reported the cage broke when he tried to remove it. It may be worth disassembling the motor completely to clean the inside and lubricate the bearings. There was a lot of dirt inside my motor. I did use a vacuum cleaner to try to suck everything out from the back side but even so, when I had it reassembled and turned it over, still more dirt fell out the front end. When the back was off I should have held it upside down and tapped it on a hard surface to get more dirt to the back of the motor and out.
I'm just going to put the motor on the shelf and hold it as a spare since I already installed a junkyard motor in its place so I won't have any long term information on the durability of my brush replacement.

But if you're facing a non-functioning 116 blower, can't find a junkyard replacement and don't want to spend $1150 on a new one, a couple of hours of work should have yours up and running again if the problem is worn brushes. I believe that what happens is that as the brushes wear down, the wire at the back of the brush will ultimately lodge at the front edge of the slot in which it slides and the spring will no longer be able to push the brush firmly in place.

bgkast · #10 02-11-2009, 02:22 PM

Quote:

Originally Posted by kerry

I bought the biggest brushes at Ace Hardware,($8.73 each) cut off the button at the end of the wire, threw away the spring and cut them down to size with a miniature hacksaw and some sandpaper. .

That's what I did too. http://www.peachparts.com/Wikka/W123BlowerBrush

utahpete · #11 01-17-2010, 02:35 PM

I'm in the process of rebuilding my 116 blower motor. I found brushes at
carbon bush dot com. They are K44, this is the number stamped on the back of my old brushes and is listed as a Bosch automotive type brush (8mmx8mmx19mm) 5.35 each

Willie White · #12 12-25-2010, 10:52 AM

Hey UtahPete I looked at the brush picture of the K44 on carbonbrush.com and it appears that the connection to the brush is brought out from the side of the brush. In Kerry's post he says that he needs to have the connection come out from the end of the brush. Did you progress far enough to determine if the K44
will work? I am also wondering what you or others are using for epoxy to hold the unit together after repair. I extend my thanks and good wishes for the holidays to you and to Kerry. Willie White

kerry · #13 12-25-2010, 04:56 PM

I think I just used five minute epoxy gel that you can buy at the hardware store. Just about any epoxy would work I think.

Doktor Bert · #14 12-26-2010, 02:20 PM

On my 116.120, you can see the exposed shaft of the blower motor behind the glovebox. When I applied sewing machine oil, followed by CLP Teflon Gun Lubricant to the spinning shaft, my amperage draw dropped by several amps.

Hope this helps....

Doktor Bert · #15 12-26-2010, 02:21 PM

Quote:

Originally Posted by kerry

"But if you're facing a non-functioning 116 blower, can't find a junkyard replacement and don't want to spend $1150 on a new one, a couple of hours of work should have yours up and running again if the problem is worn brushes....."

About $250.00 new from ******** az dot com, part #0130107023