Water Pump Installation Question

[jerrybny]

OK I ordered a new water pump from Victoria British. Is there any prep that needs to be done to the pump before installation. I seem to remember something about the water pump seal not fully seating against the back face of the impeller. Anyone ever get a water pump from VB. Anyone have any advice/expierence installing a new water pump? Thanks and Happy Holidays to one and all.

 

[Don Elliott]

Some of the new water pumps are longer inside. When you install these, the impeller (or its shaft) hit the inside rear of the housing and refuse to turn. Check first that you have enough clearance. When I bought my "new" pump for my TR3A in 1990, I noticed that the new impeller was cast iron and smaller than the original brass impeller that was in the original pump. I had a machine shop make me a stainless steel shaft to accept the original impeller and new bearing and 87,000 miles later, it still works fine. It has never leaked because it's the mild steel shaft that rusts around the seal to cause the leaks.

Don Elliott, Original Owner, 1958 TR3A, TS 27489 LO

https://www.britishcarforum.com/ubbthreads/photopost/showphoto.php/photo/1919/ppuser/4127

 

[DougF]

I installed a VB water pump this past summer. Bolted right up with no problem.

 

[AltaKnight]

I believe it's good practice before installation to run them dry using your electric drill to turn the shaft.
This allows the seal to bed in, once the coolant gets in there there's not enough friction to get the seal to bed properly resulting in leaks.

 

[jerrybny]

Run it dry on the workbench?

 

[Alan_Myers]

[ QUOTE ]
Run it dry on the workbench?

[/ QUOTE ]

No, not necessarily. You need to check with the vendor. Ask them which type seal is used in the pump and if this procedure should be used or not. I'm guessing not.

Many modern replacement pumps are built with a modern seal that *do not* require "dry run" to seat the seal. The original pumps, rebuilds and replacements back in the 50s, 60s and 70s used a different type of seal (ceramic) that required a "dry run" to seat it properly. Various service manuals outline this procedure. But it's commonly not correct or necessary for modern pumps that use modern seals.

The "dry run" can be performed on the bench with an electric drill, as described, or on the car. The latter is what's described in most manuals I've seen... simply not re-fill the coolant and start the engine briefly so that the new pump runs dry for about 60 seconds. Then top up the coolant and you are done.

Problem was that many installers were unaware of and skipped this step, topping up the coolant before doing a "dry run". Often the original style seal would never seat properly when run in coolant right from the beginning and would always weep a little, which probably shortened the useful life of the bearings and the pump.

So, most modern repro pumps or rebuilds use modern seals and no "dry run" is needed. You really should ask your vendor for details specific to the pump they provide and not rely on what we suggest here or directions in any service manual. (Ideally, vendors would include proper instructions with their pumps, but many don't!)

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