TR4/4A TR4a Water Pump failure

[richie]

I was fortunate enough to have my water pump fail on me while I was adjusting my carbs and not on the road! Now that it's failed, she's going to hibernate a little earlier.

As I've got to remove the belt assembly I was wondering what else I could do while I'm there, i.e. I believe there is a belt conversion? I'm equipped with an electric fan so perhaps a fan eliminator kit as well?

Also does anyone recommend any particular water pump? I see TRF has an upgraded and regular model?

Thanks!

 

[KVH]

Mine on my 4A also just failed. I'm installing the 6 Vane from Moss after some discussion indicating it may not be better but "might be," and should be just as good. I've had some overheating (at every summer stop light), so I'm anxious to report if anything changes other than the weather.

My two cents: the pump is easy to change, and there's no reason to springboard to a belt conversion and all that unless you were planning anyway. You don't need to remove the radiator, as you likely know, so if you're wanting an auxiliary electric fan you can also do that anytime. That's actually a fun job, mainly electric wiring.

Back to the new water pump, I was surprised mine doesn't spin like it's on ball bearings. It's actually a bit tight. I'm wondering how "normal" that is.

Good luck and let us know what you eventually decided.

 

[Geo Hahn]

...I was wondering what else I could do while I'm there...

I seem to recall that some replace one of the bolts with a stud to make future pump removal (with the pulley in place) easier. The details elude me as I have never done this but it should be easy to search & find or wait & listen.

 

[TR3driver]

Some drag from the seal is normal.

I have all studs instead of the stock 2 studs and a bolt. But I wouldn't say it makes enough difference to be changing unless you want to. I switched because I was running one of the aftermarket pumps that has the pulley permanently attached (so no way to install the bolt); but it seems they are NLA. Moss still has the stud listed, though.

Do let us know how the "improved" pump works out. My understanding is that they are only better above 5000 rpm or so, where the stock pump has a tendency to cavitate. And my experiments showed absolutely no improvement in cooling at lower rpm (although I had no way to measure water flow).

I'm also curious if the ones they supply now have the blades curved in the other direction. The pump I got (one of the very first 6 vane pumps from BFE) has the blades curved in what seems to be the wrong direction.

PS, here is another comparison:
Original:

6 vane:

 

[KVH]

The direction of those vanes in that early model does seem backwards. I checked my 5 vane from BPN, the one that just failed (lasted 5 years), and the vanes are set in an opposite of the direction as those shown in the far left picture above.

As for the 6 vane I just installed, I totally neglected to check, but I think the vanes are in the correct direction, at least the direction expected, pushing water with the convex part of the vane curves headed in the clockwise direction when looking from the front of the engine (an engineer can say it better).

Depending upon how the elections go, and whether any kind of crisis intervention is needed at my household Wednesday morning, I may engage in some creative distraction by taking the pump off and checking just so that I know.

 

[Geo Hahn]

...Depending upon how the elections go, and whether any kind of crisis intervention is needed at my household Wednesday morning, I may engage in some creative distraction by taking the pump off and checking just so that I know.

I think it would be easier to just call Moss and have them take one off the shelf and describe it. Or perhaps Shawn of Moss will see this thread and post a pic.

Then you can use any post-election distraction time to commence some steady drinking.

 

[Geo Hahn]

Ah ha! Moss has a picture of their uprated 6-vane on their site:

The vanes are indeed in the opposite direction from the pump Randall has.

 

[KVH]

That really is incredible. I can't imagine how the engineers or designers got it reversed? Was there some theory of hydraulics? Something counter-intuitive? I can't imagine it was just an accident.

 

[richie]

Thanks all, today I've placed the order for the Moss 6 vane pump along with a belt, a whole bunch of gaskets and both 165/180 t-stats so I can choose the right one! Last for the cooling system will be one of these and an thermostatically controlled electric fan mod!

 

[RJS]

This summer I ordered both the Moss 6 vane and standard 4 vane so I could compare them side by side. I wasn't convinced that the number of blades was a big deal. The 6 vane may move more water (or faster) but, I have no idea if that is desirable or not. I did choose to install the 6 vane as it clearly appeared to be a better quality unit. I also ground down the profile of the housing significantly before installation so as not to interfere with the pulley (a known issue).

Also installed Stant SuperStat 185* thermostat. This was back in July and all appears well.

Bob

 

[KVH]

Went for a long drive yesterday. After having a four vane, five vane and six vane, and after idling long at numerous Thanksgiving Weekend stoplights, I'm convinced that for my car the number of vanes in the pump is totally irrelevant. I may just buy a new radiator one day, but as long as my auxiliary fan does its job, no rush I guess.

It's just fun driving a Triumph, and out I go in a few more minutes!