Morris Minor Owners Club

I've managed to get myself a couple of Lockheed brake m/cs on the cheap but the filler nuts look weird on both of them. Do they all look like this?

I thought the Lockheed units were the ones to get, rather than a pattern unit.
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Looks like someone has had them shot blasted in an attempt to clean them up, that’s the sort of finish you can expect from that process. You need to be sure with secondhand brake parts. I’ve got a used cylinder that I feel is fine but I’m reluctant to advertise it.

And the chewed up state of the nuts arises from not using the correct box spanner New items have perfectly formed hexagons with flat sides. The filler cap will still work with a deformed "nut", but I would be more concerned about the inner workings of the cylinder.

simmitc wrote: ↑Sun Mar 10, 2024 3:49 pm And the chewed up state of the nuts arises from not using the correct box spanner

I take it a correctly sized socket is okay to use? (as in it doesn't have to be a box spanner?)

The last thing I would be doing is blasting the master cylinder.
There is an increased risk of blasting debris getting into the cylinder at the operating rod end and through the filler cap however careful the blaster was.
I would advise that you check the condition of the piston and piston bore plus inside the reservoir for blasting debris.
New filler caps are available from ESM but you may be able to find a good S/H item.
https://www.morrisminorspares.com/brake ... al-p829355

socket should be OK as the cap is not tightened excessively. The only thing to watch is that the alloy is quite soft and a socket grips on the corners or points, whereas a box spanner grips the flats. However, seated plus a bit should be fine and much better than a bodge with an open ended spanner or mole grips!

Doesn't a spark plug box spanner fit the master cylinder filler cap? 7/16 Whitworth or 21mm

Stephen

Spanner thread does say 7/16W for the cap, so if that is also the size for spark plugs (I've always just used the long socket in my socket set which is unmarked for size) then this presumably means the inclusion of the box spanner/tommy bar with the original toolkit was for both brake fluid and spark plug removal/refitting.

Anyone with the original toolkit know if this is true or not?

Thanks for the comment guys. I used a 13/16th socket to loosen the caps which weren't on that tight.

I was considering to put them in the ultrasonic cleaner and buy a service kit to recommission one of them to start with and buy new caps as Phil suggested. If success I'll do the other as a spare and flog the one in the car for someone else to do. Like Les, I'm also not comfortable selling such an item as working - even if it does.

Cheers