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TR2/3/3A Radiator drain tap?

karls59tr

Obi Wan
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Just drained the winter coolant out of the rad.The lever on the drain tap moves way too freely from straight ahead and I'm concerned it would not take much of bump to move it and dump the coolant. What's inside and is it DIY repairable? How much trouble is it to get it out? Dont want to crack the housing? I know they are not that expensive but I kind of wanted to get the car on the road rather than wait for a new on to arrive. Thinking of just wrapping the lever in place with plumbers tape as a temporary measure.
 
Original tap? It's just a solid body with a tapered hole where the tapered plug fits. On the bottom is a shaped washer, spring, and cotter pin. Remove the cotter pin, and collect the spring and washers. The tap will probably fall out, but you might have to turn it a few times. The spring tends to rust and get weak, or even break altogether. I found a suitable substitute in the parts bin and cut it to length. Sorry, no idea where it came from.

In a pinch, I've been known to wrap a worm-drive hose clamp around the handle and the body, so it forces the plug into the hole. I was on a drive away from home when I did that; then forgot all about it and drove that way for several years. Discovered it when I went to change the coolant the next time :smile:

Note that the radiator tap and the block tap are actually slightly different even though they look the same. The block tap has straight threads and takes a fiber washer, the radiator tap has tapered threads.

Also, there is a standard radiator drain valve that will fit and work fine. Doesn't look original of course, but might be an alternative. I always take the original tap out when taking the radiator to a shop, because they will replace it.
 
Note that the radiator tap and the block tap are actually slightly different even though they look the same. The block tap has straight threads and takes a fiber washer, the radiator tap has tapered threads.

BSPT for the radiator tap??
Tom
 
Sorry, don't know for sure offhand. I thought it was 1/4" NPT, as that's what my radiator shop always puts in and it seems to seal fine. But you can often get away with a slight mismatch with tapered threads, so it might have been 1/4" BSPT (19 tpi instead of 18) originally.

BSPT for the radiator tap??
Tom
 
There is a spring which presses the valve cone into the valve. It sounds like your spring may have corroded away. It can be replaced, assuming the valve is otherwise in good condition.
 
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