1.    cooling

1.1    Fixing the radiator in the TR3

From: Catpusher_at_aol.com

The most common leak is where the filler neck goes into the main body. I discovered a leak there a short time before the start of a race. I asked a very busy Brian Fuerstenau from Group 44 for advice, and he lent a torch and solder to me; and told me that I could do it in place. It worked, and I have fixed more than one that way.  You need to drain the water, get it very clean, and use the correct flux. If you get it too hot and melt too much, you had to pull the critter anyway. 

1.2    ethylene-glycol lifetime TR3 and else

From: Randall Young < ryoung_at_NAVCOMTECH.COM >

…but my experience has been that 5 years is not often enough in my TR3A.  TR3s have a particular weak spot in the soft aluminum thermostat housing bolted to the cast iron head. Running antifreeze for 5 years allowed a noticeable amount of galvanic corrosion around the inside edge of my Tstat housing.  Every 2 years seems to be working OK. Of course, this may also depend on the brand of antifreeze used, since it's not the glycol itself that provides corrosion protection but the additives in it.  I've been using either Prestone or Zerex, whichever is on sale.

 

1.3    TR2-4A Water Pump Rebuilding

From: "Fred Thomas" <vafred_at_erols.com>
On the front of the w/p is a "C" clip holding the bearings in place, remove this clip, turn your w/p over with the impellar facing up and place in a vise, using a good size punch so as not to distort the shaft, drive the shaft out the front of the housing, very easy takes about 30 seconds, if you have a press use a large bolt to rest on the shaft and then press it out., reinstalling, place water thrower rubber bush on shaft, place the lower interior "c" clip on the shaft then the abutment washer, 1 bearing facing up, spacer, 2nd bearing facing inward, load the inside space of the 2 bearings (facing each other) with grease and press into housing, reinstall the outter "C" clip, insert new rear bushing/seal in impellar turn the W/P over and press the impellar onto shaft, you want .085 clearence between impellar and housing.

1.4    Running in thr TR water pump

After installing the water pump, did you run the motor dry with no coolant for about a minute?  By running the engine with no coolant, the pump has a chance to seat into the graphite seal.  If you don't seat the pump properly it may leak after installation.