Fitting a drain plug to a car radiator.

[Dave Plowman (News)]

I've just changed the anti-freeze in the old Rover and been reminded what a b****r of a job it is. The only way to drain it is to remove the bottom hose, and access is tight so it usually means removing the alternator to get enough purchase on it.

It is an expansion tank system, so the rad itself has a filler at the top closed off by a screw in plug. It would be great to have the same at the bottom to drain it. The other side of the rad bottom from the hose (left rather than right) has easy access and a large flat face. The rad is brass and copper - no plastics on one this age.

I have a spare good rad so am considering modifying it. They are quite easy to change - once that bottom hose is off.

Suggestions about the best hardware to use as a drain? Soldering it in place holds no fears for me.

[Adrian]

"Dave Plowman (News)" gurgled happily, sounding much like they were saying:

Find an old brass/copper rad with a drain on, and hack it off?

[The Natural Philosopher]

Juts get a large brass screw and nut, solder the nut to the rad (after suitably drilling) and then use a fat fibre washer on the (cut down) bolt head.

[brass monkey]

You can still get these -

the prob is fitting it.

[Andy Dingley]

One of the neighbours did this on a seasonally used tractor. The original block had a drain tap, but it was tiny and seized solid. He went to the local Chavcar suppliers and bought a moulded silicone top / bottom hose that would fit the bottom hose and also had a side tee moulded into it. Then five minutes with bits from Screwfix and he had a big drain plug made of copper pipe bits stuck in the tee.

Now we're just waiting for blue lights under the rotovator.

Scares me. Patching old radiators is a PITA. It's OK if it's a toatl rebuild, because then you can strip and clean it properly, but doing odd bits also seems to make a pinhole appear somewhere else.

[Dave Plowman (News)]

Since it will be on a plain bit of brass, I can minimise the heat going elsewhere. I agree if trying to repair a leaking seam, etc.

[dennis]

Visit a scrap yard and get one of a scrapped cars rad?

One of these would be easy to solder in

would it work loose through vibration, etc.

[dennis]

Visit a scrap yard and get one of a scrapped cars rad?

One of these would be easy to solder in

would it work loose through vibration, etc.

[Dave Plowman (News)]

Think I need to expand the question. I wasn't thinking of a tap of any sort. I'd be quite happy with a screw in plug - less to go wrong, and would be near flush to the rad so less chance of getting whacked and broken off.

My thoughts were something like a 1/2 compression tap connector with a cap which screwed onto that - or a similar sort of thing with a female thread. The pipe end of the thread could be shortened, and the flats of the hex would give a larger area to solder to the rad body. But a quick glance at Screwfix doesn't show anything suitable.

The existing filler at the top of the rad is a T shaped boss with a female thread. This is soldered to the rad body. A plastic plug with rubber sealing washer completes the fitting. It's about 3/4" - but that's for ease of filling. For draining a 1/2" thingie would be fine.

[The Natural Philosopher]

like I said any bolt and nut that can be sealed with a fibre washer will do, if its brass.

[Cicero]

===============================================================

You might be able to adapt one of these:

female end takes 15mm tube. The screw-on cap (finger tight) has a rubber seal. The drain/bleed hole is about 2.5mm so would need to be drilled out for quicker drain. Overall length is 1".

The screw-on cap might need some kind of security fixing if there is risk of vibration.

Cic.

[Cicero]

===============================================================

Further suggestions - might be closer to your requirements:

or Screwfix radiators use a male blanking plug opposite to the bleed valve.

Wickes sell a chromed female blanking plug to blank the shower outlet on a bath tap mixer/shower.

Cic.

[The Other Mike]

In the absence of a lathe and tap a 3/8" BSP to 1/8" BSP reducer (maybe from BES?) with most of the externally threaded section hacked off will allow a decent sized filet of solder

[Jim White]

[snip]

Dave, you say you're happy soldering, so how about something like: Toolstation 98490 brass hex bush, together with 71545 flanged plug? Nice low profile for all of 96 pence :-)

[Dave]

Not if you drill a hole through the flats and wire lock it to the hose connection.

Dave

[Dave Plowman (News)]

Those look ideal. See they have a branch in Merton I didn't know about so close enough to pick up.

Thanks, Jim.

[Jim White]

In message "Dave Plowman (News)" wrote: [snip]

My pleasure. They're behind Staples on Morden Road. Been using them quite a bit lately. Oh, and Southern Carburettors are next door for when you need bits for the Rover :-)

[Dave Plowman (News)]

Ah - I looked it up and it said on the Chelsea Fields industrial estate. That's where TLC is. And Eurocarparts. You're not thinking of Plumbase?

[Dave Plowman (News)]

I've no idea where I found the Chelsea Fields address. Perhaps I clicked on the wrong part of a map. But they are where you said, and I got the parts this morning - now fitted. So thanks once more.

Nice and quiet on a Sunday morning, and not much further than the nearest B&Q etc - so I expect they'll do well out of me. ;-)