waterpump

[jan lauwers]

My waterpump has been in a batch with other parts to be electroplated. Not sure if that was a good idea or not. My plating guy said it was Ok to do it.
Now I am wondering: would it not be best to replace the bearing(s)of the WP? But, how do I open it? Any thoughts please?

My WP is of the 'short' type, (see pic), even though I don't have AC in my car.

Thanks guys!

Jan

[mdsalemi]

I'm guessing Jan, that this was not a good idea.

First, having it plated takes it away from originality. It was not plated to begin with but raw cast iron.

Second, as you can see from the pump itself, it's pretty simple; what fails on the pumps are seals. How did the seals hold up in the extremely invasive process of plating? You have different kinds of acids involved and they may have totally destroyed the pump seals.

When I replaced my water pump a few years ago, it was something like USD $70 or so. While not too expensive, it was a total bear to change for a shade-tree mechanic like myself without a lift. This is my opinion only, but I'd never put back a part knowing it wasn't good, or had the possibility of being damaged. It's too much effort to change for the second time. Perhaps there's a way to test these pump seals, but I don't know how. There are others that totally disagree with this, trying to save every cent on parts and not placing a value on their own time. The choice is yours.

[jan lauwers]

thanks Michael,

I hear what you say. Originality is not my main objective. A restoration by definition is going to take originality away. I realize this is a personal choice and I respect your opinion. I want the engine to look good, the parts be protected from rust and obviously function well. My engine is out and taken apart now, so access is not an issue. 

I guess my true question is: what`s inside this pump and can it be opened? How? I imagine that the house only contains an axle in bearings since the active part of the pump is external?
Is this correct? if so the only damage would to the bearings, which can be replaced? Am I completely wrong here? 

Thanks!

Jan
s ofd

[Shvegel]

Jan,
Besides bearings the pump also contains a carbon ceramic deal on the shaft.  One half of the seal is fixed to the body and one half is installed on the shaft.  The faces of the carbon ring and the ceramic ring are very flat and don't allow any(technically very little) coolant to pass through even under 15 psi (1 bar).

Disassembly is done by pressing the shaft out from the impeller side.  The problem is when you press the shaft down through the impeller you will crush the seal and a new seal kit costs roughly what a new pump costs.

http://www.ebay.com/itm/MERCEDES-W111-220-SE-SEDAN-COUPE-CABRIOLET-WATER-PUMP-REBUILD-KIT-121-200-29-01-/201640031826?fits=Make%3AMercedes-Benz&hash=item2ef2aeb652:g:H3cAAOSwARZXphoT&vxp=mtr

I am not sure if this is the exact kit for your pump.  I didn't look it up.

[mdsalemi]

...the parts be protected from rust and obviously function well. My engine is out and taken apart now, so access is not an issue...

As the pump impeller and casting/housing are cast iron, pretty solid, rust shouldn't be an issue. The seals will fail long before any rust gives you a problem. BTW, MB now is offering their factory pumps here in the USA as rebuilts, with a core charge for the old pump.

Access NOW isn't the issue, Jan--it's putting it all together now, with a pump whose integrity isn't known. Then, shortly after it's all together and you are working on the myriad of little issues that will consume your time after it's all together, the pump starts to leak. That's when the access will be an issue!

[Pinder]

I would put a new pump in. I tried to use my old one and it was the first thing that leaked and I had to take it off again while engine was back in the car. dont bother with rebuilding it not worth the effort.

[mdsalemi]

I would put a new pump in. I tried to use my old one and it was the first thing that leaked and I had to take it off again while engine was back in the car. dont bother with rebuilding it not worth the effort.

Q.E.D. That's precisely what I was trying to convey, Jan. Pinder's got it--sadly, the hard way!