View Full Version : Water pump lubrication

01-25-2005, 12:51 AM
So my Bentley manual shows a grease zerk or at leat a plug where you can fit one on the TR6 water pump. I don't see one on my '73. Anyone know if this is something that got "rationalized" along the way, Does the glycol antifreeze do the job instead? Thanks

Dave Russell
01-25-2005, 01:58 AM
The antifreeze does the job instead. For those that use water instead of antifreeze, there are several water pump lube & anti rust additives available. In the old days, folks were over greasing the pump & gunking up the cooling system with excess grease.

01-25-2005, 04:36 AM
Hello Dave,
I had a similar discussion on a U.K. Triumph website and my opinion is that the coolant cannot be a lubricant as the mechanical seal is between the coolant and the bearing. I actually stripped down a 2.5 water pump to see if I could replace the bearings, (expecting two) what I found was a long one piece bearing which is a sealed type.
Basically replacements are now maintenance free and there is no greasing provision.


01-25-2005, 10:07 AM
Original water pumps had grease fittings for the bearings. They were constructed with seperate shaft and bearings, having a keyway for the pulley that is held on with a nut. Aftermarket replacements generally have an integral shaft and bearing assembly where all the parts are pressed together. Bearing assembly pressed into housing, impeller and pulley pressed onto the shaft extensions. These integral assemblies have no provision for lubrication. If you don't see a nut holding on the pulley, you have one of these type of assemblies.

Also, the water pump lube most people refer is seperate from the lubing of the bearings. There is a mechanical seal between the water side of the pump and the bearing side. It's this seal, usually a phenolic cartridge with ceramic insert on the impeller side, that is the object of the water pump lube. With antifreeze in the system, this lube is unneccesary...as a matter of fact, even with just water in the system, I doubt there are any benefits to using this stuff.

Geo Hahn
01-25-2005, 11:48 AM
The original H2O pumps on TR3s & 4s had zerks, not sure when this ended but replacements generally did not have them. To my knowledge the internals are the same, the replacements are just packed with grease 'for life'. That would be the life of the pump, not our lives.

I still have a real zerk on the 4's pump... put a fake one on the 3's... lotsa luck to the future owner in 2028 when he puts the grease gun on that one!

Some crafty folks can & do drill & tap to add a functional zerk (think it takes 2 drillings to go in & then forward). Others have forced fresh grease in thru the weep hole in the snout of the pump but haven't felt the need to try either of these steps.

Dave Russell
01-25-2005, 12:29 PM
Hi Alec,
You, Martx, & Geo are all correct, the only thing that needs lube is the face seal. The only time there is trouble with the face seal is if it is run dry for TOO long. In fact it is sometimes recommended to run in the face seal for a very short time by hand before subjecting it to coolant lubrication. Spinning the impeller against a wire wheel buffer works well.

01-25-2005, 04:47 PM

Dave makes a good point of spinning up the water pump dry. A few seconds is all thats needed to lap the water seal to the pump housing creating a matched smooth surface on each. This is not always done by manufactures. With coolant of your choice in the system, it lubricates the seal face so much that irregularities are not smoothed.

Regarding shaft bearings, originally these bearing had open races so periodic lubrication was necessary. Replacement water pumps us sealed bearing, so forcing grease into the housing somehow serves no purpose in mind. Excessive over greasing of early (original) water pumps can disturb the water seal and cause a leak. More is not always better.

Safety Fast,