Thread of swivel drain plug ?

Thanks for all the replies, I asked the question so I could buy a longer bolt to clean out the thread before putting the plug back in, as I seem to have a sudden leak from the drain plug.

I am surprised that so many think it's a tapered thread, given that there is a copper crush washer to seal it, so wouldn't that defeat the purpose of the tapered thread ????. I do believe the filler is a tapered thread, as there is no head, or water on the "bolt".

Anyway, I'll order some new copper washers, take the plug to the bolt shop, and mention 3/8 BSPT and see what they say.

Although if it is a tapered thread, then I won't be able to buy a longer bolt anyway, it just won't go in - right ?

Oh and thanks Shane for the offer of the drain plug, but I should be good.

Thanks
John

Quote:

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Originally Posted by JohnboyLandy

Thanks for all the replies, I asked the question so I could buy a longer bolt to clean out the thread before putting the plug back in, as I seem to have a sudden leak from the drain plug.

I am surprised that so many think it's a tapered thread, given that there is a copper crush washer to seal it, so wouldn't that defeat the purpose of the tapered thread ????. I do believe the filler is a tapered thread, as there is no head, or water on the "bolt".

Anyway, I'll order some new copper washers, take the plug to the bolt shop, and mention 3/8 BSPT and see what they say.

Although if it is a tapered thread, then I won't be able to buy a longer bolt anyway, it just won't go in - right ?

Oh and thanks Shane for the offer of the drain plug, but I should be good.

Thanks
John

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If it is 1/4" BSF then it is a parallel fastening thread not a pipe thread. It will need a gasket, o-ring, copper washer to seal. As does a Pipe Parallel thread. Pipe Taper seals on the thread and only needs a wipe of sealant or some teflon tape.
To clean the thread get a 1/4" BSF intermediate tap.

mine are not tapered, Swivel drain plug. pulled them out a couple of weeks ago, to change oil. Filler/level plugs are tapered, same thread a gearbox level plug.
always add a smear of 515 on the threads, Henkel Loctite 515 Gasket Eliminator Flange Sealant Purple 50 mL Tube when replacing such plugs.

whitehillbilly

Quote:

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Originally Posted by JohnboyLandy

Anyway, I'll order some new copper washers, take the plug to the bolt shop, and mention 3/8 BSPT and see what they say.

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They might laugh at you.....

The filler/level plug is 3/8" BSPT, drain plug is 1/4" BSF with a sealing washer. You will struggle to find a bolt shop that carries BSF and may find that they have never heard of it.
The original drain plug had a very long hex section, about 4 times the head depth of a normal bolt. I guess this is because it sits in a recess and it makes it easier to get to.
https://www.seriesforever.com/8316-t...ter-pivots.jpg
Some of the washers used are folded over with some sort of gasket material in the middle (asbestos originally no doubt), others are solid copper.
If it's solid copper then heat it up till it's cherry red then quench it in cold water. The copper will be soft again and seal better.
I've done this with the composite ones but the substance in the middle is full of oil so it gets a bit smokey and there are a few flames.....
Quite often new copper washers are supplied 'hard' so you have to anneal them (as above) before they will seal properly.
Some sealant on the threads wouldn't hurt.

Is it definitely the drain plug leaking ? A leak round the edge of the swivel seal would show up at the bottom near the drain plug.


Colin

Thanks, I have some 1/4 BSF bolts anyway that I sourced from the UK a while back, so I will drain the swivel, run a bolt through to clean the thread, install new copper washer and original plug with some hyolmar on the thread.

Cheers,
John

Readily available in Oz if you know where to look. Bruce Gardner of B.S.F. Bolts in Melbourne has stocks of BSF & BA fasteners and taps and dies. Classic Fasteners in Adelaide has them but I have found them a bit expensive for my liking. I still have stock of some sizes of BSF taps and dies including a few left hand.

Quote:

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Originally Posted by JohnboyLandy

Thanks, I have some 1/4 BSF bolts anyway that I sourced from the UK a while back, so I will drain the swivel, run a bolt through to clean the thread, install new copper washer and original plug with some hyolmar on the thread.

Cheers,
John

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Make sure you anneal the copper washer before you fit it.


Colin

Quote:

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Originally Posted by Bigbjorn

Readily available in Oz if you know where to look. Bruce Gardner of B.S.F. Bolts in Melbourne has stocks of BSF & BA fasteners and taps and dies. Classic Fasteners in Adelaide has them but I have found them a bit expensive for my liking. I still have stock of some sizes of BSF taps and dies including a few left hand.

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That's good to know for future reference. I had bought off Classic Fasterers in the past, just for the (2BA ?) screws to fasten the dash panel to the firewall. But yeah, I noticed they were a bit exe for BSF.

Cheers,
John

Quote:

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Originally Posted by gromit

Make sure you anneal the copper washer before you fit it.


Colin

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Hey Colin, what to mean by "anneal" it ? How and why ??

Thanks
John

Hi John,

I believe that he means to heat up the metal, before installation. I have heard of this before when using copper washers. A quick Google says:

Annealing is a heat treatment process which alters the microstructure of a material to change its mechanical or electrical properties. Typically, in steels, annealing is used to reduce hardness, increase ductility and help eliminate internal stresses

Hopefully Colin or Mick88 might be along shortly to explain it better.

Cheers,
GG.