W 11x and others heater blower

[jim 56]

Hello all just finished replacing the blower fan in my 1972 280SE W108.Very hard job spent a lot of time.If anybody is about to do this feel free to PM me as I have some insights that I wish I knew before I started it.

[wwheeler]

Where did you find a replacement? Was it the motor or the fan itself?

[ja17]

Yes, a big job, congratulations! I have done quite a few and it is intense. Mostly everything in front of the seats must be removed. Mercedes book time on the job is over 16 hours, but I do not know anyone who ever made that time. The W108s with the V-8 engine are a little worse. Wallace, the W111 chassis is not as bad, but is still a project.

[Pawel66]

Do you happen to remember how many hours Daimler booked for heater core replacement in the W113?

[jim 56]

the blower motor itself was good the plastic that holds the motor itself had broken allowing the motor to slide and jam.I bought a motor from a company in Fla. that I had to jury rig to fit because of the broken plastic.I sent the heater core out for reconditing and replaced the "o" rings.I know this sounds crazy but if I had to do it again I would have taken the windshield out.

[wwheeler]

It has been said that the car was built around the blower motor and housing. I have also heard that if the cowl area is rusted badly, it is near impossible to repair correctly. One day soon....I will get in there and replace everything just like you did. I have new heater cores I bought about 10 years ago because mine were leaking and I by passed it.

I made a special pipe from copper sweat fittings that bypassed the heater cores. It inserts into the heater core inlets, but that is for support only. I have that on my car for about 8 years now. I painted it high temp black so that it looks like the original.

[jim 56]

The reason I thought about taking the windshield out is that it would have made it easier to get the dash wood the vents and the cables off of the top of the heater.My hands do not work the way they used to and getting all that stuff in and out I was getting cramps in all my fingers.The motor I got from florida was smaller in diameter so I made a metal sleeve to take up the difference.Then I drilled and tapped the broken plastic to hold the sleeve in the plastic.I did see somewhere someone was selling the whole motor plastic and squirrel cage but it was over a thousand dollars.One thing I did have to buy was the rubber gasket that seals the squirrel cage to the body.that alone was 80.00.

[JPMOSE]

Congratulations!!  I did the heater cores on my W111.  It really wasn't that bad.  The only issue I had was the O-rings being too stiff in the water valves.  The right side won't even move, so I'm going back in and removing the valves.  I had sent the cores to the radiator shop to be boiled out and they were in great shape.  I removed the fan and checked the brushes (looked almost new).  Replaced the seals that go around the heater cores.

So what's the trick to making the valves turn easily?  If seen this complaint about the 113 as well, but I don't remember mine being a big issue when I replaced it.

[wwheeler]

I can answer the issue with the stiff turning valves. It is probably the O-ring. The O-ring used is a 3mm metric O-ring. If you go to a hardware store and match it up, they will give you a 1/8” imperial O-ring because they are very close. The difference is in the cross section between metric and imperial inches. To be exact, the metric will measure .118” and the inch size will measure .139”. That is a difference of .020” and quite bit. So if you use an 1/8”, it will bind.

The other possible issue is material choice. The O-ring material must be compatible with coolant and 200*F. Most hardware stores do not specify what material, so you have no idea. EPDM is an ideal material for this. If the material is NOT compatible, it may swell and bind over time.

Or you can buy the O-ring from Mercedes and it should be correct.

Wallace

[PeterPortugal]

This was the very first job I did on my car. The previous owner had done something similar to Wallace but far less elegant. Right up there with replacing a speedo or tacho for jobs you absolutely do not want to do.

[austinado16]

Did mine a few months ago because the blower motor was seized.  Fortunately, I'm a small guy so I can get right in there have a proper amount of fun.  Literally the heater/blower assembly and the wiper transmission were hung by strings and sent down the assembly line first.  What were they thinking!  And then on the coupes, there's actually no functionality for taking in "cooler" outside air and blowing it onto the passengers, which makes the cars undriveable (IMO) on hot days, unless you're simply cruising around town with the windows and roof open, at low speeds...or you have an air conditioner.