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MG MGF Technical - Radiator Plastic Bleed Screw (crap)

Hi,

back to normal stuff after having spent hours on the Treffen pictures.

On Sunday it happened to 'the bad luck king' Erik, that the mentioned screw got damaged.

http://www.mgfcar.de/treffen2002/dcp_1449.html
The bolt head just fell off and coolant poored out. This is not a unique case, I know of two other cases from this BBS and a german F'er who had the same trouble after dealer works at the coolant system.
The weak bolt gets obviously overtightened and then it starts to stretch and the head brakes off after more or less short time.

Temporary fixture was to cut a slot into the remainig thread part for screw driver access and to wrap the thread with Teflon tape and rebolt.
http://www.mgfcar.de/treffen2002/dcp_1451.html

OK. No long term solution and Mike got already shining eyes regarding supply of another useful part made from metal to the 'engine live safer kit.
:)

Anyway, my question in advance for DIY works is...
What thread dimension is the bolt ?
I measured roughly about 11.5mm outer diameter and Ted analysed in first assumtion that it could be imperial thread, 3/8 inch ???

3/8 is a standard thread at plumbers parts for pressed air and water lines.
3/8 is app 13mm outer diameter and app. 1.5mm inner diameter.

Now the question is whether anyone out there with a spare or broken radiator could check whether a standard 3/8 part will fit or not.

Best regards
Dieter < -- likes to change that thing to a stainless steel bolt

Dieter K.

The Treffeners' conclusion is that it is probably 3/8 BSP. The problem with replacing it with a steel bolt is that the rad tanks are plastic too, and so overtightening it again (by the garage monkey!) will ruin the radiator....but MS supplies replacement metal rads and plugs....seems like the only real solution.
David


Hi all,
Yes, that one is a worry as it after some use get "soft" and doesn´t have a well defined end torque.
So the idea of fitting a 3/8 (or whatever it is )permanently with some suitable Lock-tite and then do all the bleeding on an additional metal bleed screw made as an insert into that one might be a good thing.After all the bleed opening doesn´t need to be that big, a M6 X1 or even M6X0,5 would do fine and last forever !

BR, Carl.
Carl Blom

When I lost my radiator plastic bleed screw into a hole in the bodywork while I was refilling the cooling system I made a succesful bodge by screwing in a spark plug with the correct thread dimension. Don't remember now what size it was but I think it was 12mm.
jon

Hi,

@ Jon, M12 x1.25 ?? is not MGF, though from a power mower or motor bike ?
The plug thread of the MGF is 14x1.25 ?

To be verified.
If Withworth, then probabbly 15/32 inch (11.9mm) would be the right.

At last I'd take Carls idea and want a metal plug with an insert like at the brake bleed connection or the MGF upper bleed point at the heater radiator.

Miiiike !?!?!!

BTW the not well defined torque of the sh*t plastic bolt could be caused by the big rubber washer under the head. At minimum I'd suggest to grease it with silicon grease or 'plumber heat water tap grease' beforte I'd but it back.

Dieter

Dieter K.

I'm sorry, me again.

Just looked up.
M12x1.25 spark plug thread relates nearly direct to Withworth 15/32 pipe diameter and thread.

I think that's it. Who tries first ?
:oD
Dieter K.

So my guess at three eigths BSP wasn't bad - but I did say it looked like a Whit. thread.

Ted
Ted Newman

*g*, As usual, Ted. The 'Mechanics' eyes !
Dieter K.

This thread was discussed between 10/09/2002 and 13/09/2002

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