Clutch master question

[ChrisM]

Found a Lockheed master marked up as 0.70" bore. Is this a brake rather than a clutch?

[Spider]

They did fit 0.70" Bore Clutch Master Cylinders to the early cars.

Apart from a part number, you'll need to look at the angle of the reservoir as they are different to the brake ones. Also, the Brake M/Cs are fitted with a residual pressure valve.

[LarryLebel]

In a clutch master the line defined by the centre of the filler cap and the hole for the hydraulic pipe is parallel to the line defined by the holes in the mounting flange. In a brake master said lines are at right angles.

[1071 S]

However, provided you get the right sie/fit the correct internals.. the cylinders are interchangeable. The correct set may be neater but the "wrong" parts will fit.

Cheers, Ian

[ChrisM]

Thanks guys - Its a brake master. I will just have to keep looking.

Cheers: Chris.

[Tim]

It's possible to rotate the reservoir. It will mean re-soldering it. A bit fiddly but not too difficult.

Tim

[ChrisM]

Thanks Tim.

Before I go scrubbing at this thing: Its not Cad plating is it? Doesn't look anything like Cadmium to me. I am sure this has been done to death, but what the general consensus on that dull finish? Some sort of Zinc plating? I have acquired a couple more in a bad state, so may give it a go.

Cheers Chris.

[Tim]

I've never worked out what the plating is. When I did mine I took them to a local plater and he said "Its not zinc and I can't replicate it." Not very useful.

Tim

[Spider]

I've never worked out what the plating is. When I did mine I took them to a local plater and he said "Its not zinc and I can't replicate it." Not very useful.

Tim

Tim, have you ever soldered them? Give any trouble doing so?

I did a while back but I don't recall it being a difficult finish to soft solder.

But, I do emphasise, it was a while back.

If they were Zinc they'd give some grief soldering them without the right flux (salts if I recall). CAD and Tin both solder easy.

[ChrisM]

I read that zinc would be a problem to solder, which should give a clue. I would still not totally discount it. Cadmium plating should not be be heated - the fumes are very dangerous.
Anyone else got solid information on this? I can get a definitive answer, but its not cheap.

[andy1071]

From my recollection, it's a phosphate coating, but whether of zinc or cadmium, I couldn't say.

I think Lockheed stopped using cadmium plating in the '60s, but not sure when...
(My late father was foreman in the plating shop at Lockheed, but I can't remember what he said about it...)

[Tim]

I soldered mine with Kemtex B916 Tinning compound. Its a suspension of 60/40 lead and tin powder in zinc chloride and ammonium chloride. The liquid acts as a flux.

If I remember my high school metal working days the flux for soldering zinc was hydrochloric acid, the reaction with with the zinc forming zinc chloride, so I'd expect this stuff to tin galvanised as well as other surfaces OK. I certainly had no trouble with it.

When I pulled mine apart, the reservoirs appeared to originally have been tin-plate with soldered seams. As I heated the reservoirs I noticed that small beads of silver metal were forming on the surface from underneath the surface corrosion. Since I was only getting them hot enough to melt solder it shouldn't have been hot enough to melt zinc.

They may have originally been finished with different finishes on different parts, before being assembled.

The only way I could find to make mine look uinform was to tin them all over. They came out a bit bright, but have greyed off a little now, about 5 years later.

Tim

[dodge44]

Thanks Tim.

Before I go scrubbing at this thing: Its not Cad plating is it? Doesn't look anything like Cadmium to me. I am sure this has been done to death, but what the general consensus on that dull finish? Some sort of Zinc plating? I have acquired a couple more in a bad state, so may give it a go.

Cheers Chris.

After a degrease and some light fettling in the worst rust areas I found a good dunk overnight in Evapo-rust (Available from Frost) cleaned the cans up nicely. Trouble is, if there is a little too much rust you get pin prick holes as the tin is very thin. As stated elsewhere though these can easily be soldered up if you have a good tin of flux (I used Flys fluxite) and a big enough iron...

[Tim]

I derusted mine in citric acid. One of the reservoirs was very badly pitted, so I swapped the tin can off a better later one that I had. The other wasn't so bad, but you can see in this photo the pitted one has a rougher texture.



And the 'before' picture


Tim