I had to rebuild a water pump to a 250GTE engine this week, but I first had to get the impeller off!

When I first tried the 12mm acorn nut that held the impeller on the shaft, I could feel it wasn’t going to move that easily. If the nut was seized onto the water pump shaft, and I continued to force it, the shaft could shear and it would be a lot more trouble and expense to find a replacement water pump shaft. The best way to loosen this nut was to use the “heat wrench” to break the bonds holding the nut in place. A carefully placing an oxy-aceletene torch flame on the nut to reach a dull red color quickly can usually create different contraction rates of the parts so the nut will loosen. Since the impeller is bronze, care had to be taken not to melt it in the process!

The heat worked like a charm, and I soon had the water pump disassembled.

The face of the impeller was pretty well worn, but that is why this part is replaceable. Vintage Ferrari water pumps have a design that leaves a lot to be desired. They often fail and leak and are not very reliable. Look for a solution in an upcoming post!

Before I attempt to get this water pumps rebuilt, I had to address the corrosion on the pump. After removing the crud, we can see a lot of the aluminum was eaten away by electrolytic corrosion. Although the efficiency of this water pump will be compromised, we’ll have to weigh this against the cost of a replacement. Time to get on the phone!

TomYang.net Monterey Cocktail Party

This year’s party has moved away from Quail Lodge to a house in Carmel-by-the-Sea generously co-hosted with the Coady Family. It will held on Thursday the 23rd of August starting at 6pm. If you’re in Monterey for the car weekend, I would love to have you come. Please contact me privately for details: tom@tomyang.net

My plans this year is to attend the Quail show on Friday, Concorso on Saturday, Pebble Beach on Sunday. Somewhere in that time, I’ll head to the track, preview the cars at the auctions, and squeeze in a few meals. Reach out if you want to meet up!