Ferrari 355, 360, 550, 575, 612 Water Pump Rebuild using 3D printed PST-01 tool

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I had a weird rumble and some dribbles out the weep hole of my water pump on my Ferrari 360 so while I was in there for a belt change, I decided to do the water pump rebuild.

The water pump on a Ferrari 360 is unusual in that to repair it, the bearings and seal are replaced instead of just replacing the entire unit. Rebuilding the water pump isn't trivial. It requires some specific tools, like a press (2 ton minimum) and suitable dies (30mm socket worked for me) to press out the existing bearing and seal and install the new ones, and a Ferrari specific tool (PST-01) to install the seal.

Here's the PST-01 tool:
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The special tool is required because the seal (G in the diagram) has to be pressed into place on two surfaces. The body of the water pump and the impeller shaft. In between is a fragile seal made from ceramic and plastic that is easily deformed, crushed, broken, or shattered. The special tool keeps the stress off the seal and on the metal surfaces of the seal so that both are pressed down to the right depth at the same moment.

The tool is rather simple but requires a tight tolerance. Since those tolerances, and the PST-01 tool are unavailable, it has to be designed and built before the seal can be installed.

From what I can figure, it looks like the shaft seal has to end up being on the same plane as the back of the impeller. The body seal has a stop built into the body where it ends up. The difference between those two heights is also the distance between the shaft seal pressing surface and the pressing surface of the body seal.

Here's the tool I came up with:

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Ricambia had a nice warning on their seal package:

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Neither the PST-01 tool nor the Three Bond 1311 sealant exist. I used my own tool and Permatex Water Pump Sealant instead. I've used the Permatex stuff before and it's got a good consistency and is easy to use. It would be nice if @Ricambi America updated their label.

The tool worked perfectly. Here's the result. A rebuilt waterpump.

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Here's a link to the tool for downloading and printing:

https://www.printables.com/model/572233-ferrari-355-360-550-575-612-water-pump-seal-tool-p

I wrote a detailed article on how I did it with more pictures.

https://www.ferrari360.org/2023/09/ferrari-355-360-550-575-612-rebuild.html

The https://www.ricambiamerica.com/water-pump-kit-1.html kit comes with two O-rings. The smaller is supposed to go on the bearing when its pressed into the housing. That's silly. There's no way that O-ring is going to fit. Besides, what's the point of that O-ring? It's outside the pressure area and there's nothing to leak past it. The weep hole is between the bearing and where that silly O-ring should go. I suggest that @Ricambi America drop that second O-ring and throw in a Woodruff key for the pulley instead.

 

@360+Volt=Prius - The warning on Ricambi's label is an understatement. The previous "fix" to my water pump, done by professional Ferrari techs, was botched and caused a long term rumble and leaks from the weep hole. Caution must be used when pressing in that seal.

It's almost funny how these supposed experts can't do anything right. These aren't complicated jobs and a trained technician with the right tools should be able to do them correctly.

 

Thanks! The kit was easy to use and the instruction label with the stern warning was important.

 

My second choice was to run one off the lathe but printing it was a heck of a lot easier. I used Amazon Basic black PLA. It's a strong but brittle material. I made a test article and it crushed the old seal, so I was confident it would hold up to the pressure required to set the seal. It worked perfectly. The tool wasn't even marred.

Here's the test article. The old seal is below it. I wanted to find out which would give first: The PLA test or the seal. The seal folded like a cheap suit first.
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