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MG MGA - turn switch repairs

The amount of previous abuse of my A never ceases to amaze me.
Latest discovery is the thread is stripped on the panel mount thread of the turn signal switch. I'm thinking of building it up with epoxy and re-cutting it. Not sure of the thread size, but maybe the mounting ring nut will do as a tap for plastic?
Any other ideas?
Art Pearse

Very hard to get anything to stick to that Bakelite, try spraying the ring with WD-40 and run it onto the repaired switch before mounting it in the dash.
David Werblow

Dave, you mean use WD40 as a cutting lubricant?
Art Pearse

That's my thinking, but to be honest, I've never been able to get anything--J-B Weld, epoxy, to stick to the switch housing. Good luck!
David Werblow

OK, first stage - build it up with epoxy. It seems to stick OK.
I measured the threads. 0.721 minimum inside dia on the ring and looks like 24 tpi. Doesn't conform to 3/4 NF which is 16 tpi.
So I guess I will have to use the ring as a tap. Or try to set up the lathe for 24tpi.

The washer replacement seems to be going OK. Used some upholstery leather and forming it water wet using the piston and cylinder of the switch. I'll leave it to dry 2 days then grease it up.
Art Pearse

So, the washer set nice in its new position. i geased it up with vaseline and tried it with the bleed screw shut. the fit was too loose as it went in easy and popped out straight away. I then tried vinyl electrical tape on the piston underneath the washer. But it seems I get it either too tight - won't retract at all even with the bleed open, or it's too loose and retracts immediately. It seems like the washer should have some spring in it, whereas mine is too floppy. I have also tried light oil instead of vaseline.
Any advice?
Art Pearse

Art,

Have you tried replacing the cotton-wool plug under the bleed screw? they can get packed a bit to densely and restrict the air flow.

Regards...John
J Bray

Be careful not to tighten the bleed screw to tightly.
I cracked mine putting to much force on it. It is only fragile Bakelite.
Fortunately, I had a back up.

What's needed, in my opinion, is an electronic device that would keep the turn signals on for approx. 30 seconds after being activated by the original turn switch. If you make the turn and no longer need it blinking a quick flip of the turn switch in the opposite direction would cancel it. This would be a stealth installation behind the dash.

Just a thought.

Cheers.

Larry
Lmazoway

The bleed screw is effective - it shuts off completely and also is not restricted when open. it seems to be that the washer will not spring itself up to the cylinder wall , it has to be packed.
Art Pearse

Art-

Upholstery leather is too thin and not tanned correctly for this application. What you need is "oak tanned" leather, such as is used on boot soles, get it from a cobbler. Oh yeah, not any more. If you could find it, the piece would be cut as a disc with a beveled edge, with the thin edge acting as seal, and the thicker bit as a support. The beveled edge is the meat side, and the hair side is turned down so that it is the actual seal surface. This would then be formed wet in alcohol, dried, and lubricated with neatsfoot oil. Failing a harness maker or cobbler, you can make a support/expander out of polyethylene sheet, like coffee can tops. You might actually make the whole thing out of that, if you can figure out how to bevel the edge in the lathe.

I was mightily displeased when I spent some time searching for a repair kit for my Hein-Warner floor jack, finding that the company is gone and the repair kit was %80, for a couple of O-rings and a leather cup seal - and the f&*#*Z( seal was too soft and it still leaks all the oil out on the floor, especially when the weather changes. So I need to make one too - but it is easier to have a hook which lets me keep pressure on the jack seal, so I haven't.
You might find a real leather seal which could be adapted from McMaster-Carr, or an old time hardware store - what hand water pumps used.
Oh, yeah...

The threads on the switch are likely British Standard Brass, as Lucas did not use UN threads on anything. (Except before WWII, when they were USS/SAE oddly enough!)

FRM
FR Millmore

May well be worth a try:
http://www.heritagefootpumps.co.uk/leather-washers
N McGurk

Neil-
Nice description, slightly different process. Mine was from an old timer, relating to pumps associated with steam engines and oiling systems. And I forgot part of it, namely that the leather was soaked in wax dissolved in the alcohol. That would be the petroleum derived wax we call paraffin, such as is used in canning or candles. The wax both stiffens and permanently lubricates the leather. The alcohol is more aggressive than water in softening the leather. It can be used for things like moulding leather to complex shapes like saddles, or locally if your boots are too tight over a toe or two. I've done that; soak the area while you are wearing them, and go about your business until it dries = works fine.

FRM
FR Millmore

Art I have the same problem with my switch. Switch works fine, but the securing bezel nut will not tighten on the threads. Let me know how you make out please.
C.R. Tyrell

This thread was discussed between 29/10/2012 and 11/11/2012

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