Drain taps

[Rodbr]

Tried to order radiator drain tap for TR3a and am no 138 in the backorder list.

 

Anyone tell me what the thread for the radiator is?

Anyone tell me what the thread for the block one is?

Think it is a 1/4BSP for radiator.

rgds

Rod

[bigmalcy]

Rod

I can't give you an absolute answer, but I can tell you:

 

1. Our radiator drain tap broke when we tried to remove it, and we elected to replace it with a plug. Couldn't think of any significant downsides to not having a tap. Access isn't too bad for when we want to drain the fluid in future.

 

2. I think that I discovered that the thread for the engine block drain is exactly the same, even though the part numbers are different. Not sure what the difference is between the parts (the radiator tap looks chunkier).

 

3. Most importantly, I think that my dad and I found a spare radiator drain tap in his box of collectables after we'd put in the plug. I'll be up there in a couple of weeks if you want me to look it out and send it to you. Not sure of value, but they sound rare ;-)

 

Malcolm

[Don Elliott]

Rod - Roadster Factory have the water tap for the block (61478) in stock for under $20.00 US.

 

Cheers

 

Don

[ianc]

I seem to remember that the tap for the block has a taper thread whereas that for the radiator does not, so the latter may need copper washer(s) to seal.

If stuck, use a plumbing fitting with the correct thread.

Ian Cornish

[Rodbr]

Hi Don,

I spoke to Moss today and although listed they have not seen one for a year and they are made in a batch in Korea. As said I would be no 138 on the back order list.

 

I think I have tracked down 2xNos ones today. Maybe delivered tonight.

I have already tried lapping the taper core and it still leaks just a drip.

 

Hi Ian,

I think you are right but if I get two of either type and the guy has been on the money before I will be able to sort it out.

It seems that TR owning is going to be a lengthy process of catch up and constant fettling.

Still lots of lessons being learned.

Rgds

Rod

[mjdearing]

just search for brass drain tap on ebay theres loads and also some correct type.

[Dave Larnder]

Hi Rod

I couldn´t get my block drain tap to seal properly, so I took it out and replaced it with an ordinary blanking plug - end of trouble!

Dave

[Willie Felger]

Hello Rod,

 

I know this is sacriledge to some, but when I had my TR3A rad recored I think the brass drain tap came from an MG Midget or B.

 

As I use waterless 4 Life (also from MGOC) in the rad there's not much risk of seizure.

 

Keep TRucking!

 

Willie

[Chris59]

Most of the new repro drain taps i had leaks : I always use a brass plug, made from an used (or new) dead tap, cut and torch weld to blank the hole.

 

Radiators taps should be conicals, block tap use a washer seal (red fibre do the job perfectly).

[BrianC]

Leaking original taps can be fixed by disassembling and lapping-in with fine valve-grinding paste (or even T-Cut or AutoSolvol). I guess this is also probably a wise precaution before installing a new repro tap.

Edited February 27, 2013 by BrianC

[Ian Vincent]

I can't remember the size but I'm pretty sure the drain tap for the block is a plumbing thread (BSP).

 

I bought a tap from a chandlers for about £4.

 

Rgds Ian

[Dave Larnder]

Leaking original taps can be fixed by disassembling and lapping-in with fine valve-grinding paste (or even T-Cut or AutoSolvol). I guess this is also probably a wise precaution before installing a new repro tap.

Hi Brian

Tried all of those media including Brasso and none worked hence my blanking plug.

 

Dave

[Rodbr]

Hi Brian,

Tried lapping and happy enough but still leaks. Spring weight seems to be the key to a good seal and getting the correct spring seams difficult.

 

Hi Ian,

Nice thought but no chandlers close by and live in the sticks.

 

Two Nos ones arrived last night from a local tractor/trade show supplier. Still coated in storage wax and been in the box for 50 years. Result! I hope.

 

Always strikes me as a bit strange to have a closed position "inline with flow" as opposed to 90 degrees to flow.

 

Rgds

Rod.

[BrianC]

Spring weight seems to be the key to a good seal and getting the correct spring seams difficult.

 

...

 

Always strikes me as a bit strange to have a closed position "inline with flow" as opposed to 90 degrees to flow.

I bought a bag of assorted springs from an autojumble many years ago and find that cutting a section from one of these solves most spring problems on the TR. It certainly worked on an ancient drain tap. The strange tap orientation has caught a few people out, especially if the tap on the engine block is badly corroded and not obviously dripping in the open position after draining and refilling. The error only manifests itself once up to operating temperature and pressure and then may not be noticed until, after several runs, the water level is critically low.

[Don Elliott]

Don't tell this to any concours judges but both of my drain taps were leaking so I took them out and drilled and tapped the innards and inserted a pipe plug which is hidden inside. I did this about 7 years ago and have had no leaks since. It's like you chaps above who just inserted a threaded pipe plug - but the judges will look at mine and it "looks" correct.

 

In the next few weeks, I plan to drain my radiator at which time, I'll merely remove the entire tap from the bottom of the rad.

 

It doesn't matter what you use because the anti-freeze mix splashes all over the cross memeber and all over the floor - just like the tap does.

[jimt]

Be warned - the thread on the radiator and block is a different thread- that why some of you get leaks .ie if you get the wrong threads. Rad is BSP block is from memory!!!! UNC . If you get someone experienced at Moss they should tell you this - after all they do have different part number. All the ones on the web are generally BSP radiator taps. You will find the BSP one will start in the block- but will need some extra leverage to go home - perhaps why some use a copper washer to seal them as the tend to still leak ( for obvious reason) if used without!

[BlueTR3A-5EKT]

Don't tell this to any concours judges but both of my drain taps were leaking so I took them out and drilled and tapped the innards and inserted a pipe plug which is hidden inside. I did this about 7 years ago and have had no leaks since. It's like you chaps above who just inserted a threaded pipe plug - but the judges will look at mine and it "looks" correct.

 

In the next few weeks, I plan to drain my radiator at which time, I'll merely remove the entire tap from the bottom of the rad.

 

It doesn't matter what you use because the anti-freeze mix splashes all over the cross memeber and all over the floor - just like the tap does.

 

 

Try this Don - stood in drain tray between chassis and radiator drain.

Available in North America from Spruce Aircraft

http://www.newpigukblog.co.uk/2011/01/the-worlds-first-funnel-that-is-a-flexible-draining-tool/

 

Cheers

Peter W

[Rodbr]

I find that if I need deformable funnels a plastic Milk carton/bottle thing from the supermarket with the bottom cut out. For the radiator cut it at an angle.

Food and a funnel for under £1, can't be bad.

 

The two litre ones can be used with bottom cut out below the moulded handle can be used to good effect.

[Fireman049]

Hi All ~

 

I got my two drain taps from Sercks radiator repairers.

 

Tom.

[PeteT]

Hi Rod, what about some pictures of your TR2. It sounds really tasty, would love to see it.

 

Regards, Pete

[irrational]

I know this an ancient thread, but have a simple issue to ask about.

 

1: I assume both block and radiator taps are supposed to have a little "arm" that opens and closes? My rad plug doesn't seem to have an arm.

2: How do I actually operate the arm? My block tap is not budging by hand and I do not want to risk breaking it. Do I just have to twist, or do you have to lift and twist or something?

I do not want to remove the whole plug in case it breaks a good seal. But I guess I could. Otherwise, can I loosen the bottom radiator hose, put a hosepipe with running water at the top of the radiator and just run the engine to clear out the radiator flush chemical?

[Hamish]

My block tap is just a 1/4 turn to open it

Unusually (I think) the handle when closed lines up with the tap opening. Counter intuitive to most "gate" valves I've come across.

Edited July 3, 2017 by Hamish

[irrational]

Thank you!

I suspect mine is then likely gunked up so it doesn't turn easily.

I'll have to try some light tapping with a tool and Q20 to see if it loosens up.

 

Dirk

[Ian Vincent]

When I had my radiator repaired I had the tap removed and the hole brazed up so there is no tap in the bottom of the radiator. When I want to drain the coolant I loosen the bottom hose.

 

Rgds Ian

[ianc]

I have met block drain taps which are open when the handle points in the direction of the hole, and taps which are open when the handle is at right angles to the hole. Very confusing!

Don't use too much force as the handle can break off.

In the 1940s and 1950s, drivers often used antifreeze only in winter, with the result that a great deal of corrosion occurred inside the engine. In the early 1960s, on my brother's TR3, we found that the tap had been left open, but such was the accumulation of crap that no coolant had leaked out. We removed, cleaned and freed the tap, and removed as much of the crap as we could using old screwdrivers, wire and lots of running water.

Ian Cornish