Wanted: Ruby Brake Component BK76 or Suggestions for Repairing It

[Jamie]

Does anyone have a spare part BK76 for a Mk1 Ruby that they would be willing to sell? 


  Screenshot 2025-05-25 094224.png (Size: 76.31 KB / Downloads: 480)

In trying to remove the final amount of wear in the trunnion hole, I managed to ruin the thing altogether by over heating it and melting the thin edge, away from the main body. I imagine that it could be built up with weld and reshaped, but I am not sure how strong that would be. I also wondered whether the two "holes" could be cut off altogether and new steel pieces welded on instead.

I would welcome either a replacement part if one is available for sale or suggestions for repairing it.

Cross-with-himself,

Jamie.

(Moral: do not try this sort of thing when you are tired.)

[Chris KC]

Sorry to hear that Jamie. Have you tried Tony Leslie (Holmesdale Sevens)? I should have thought he could find you one.
https://oldcarservices.co.uk/austin-seven-specialists/

[Jamie]

Thank you for the suggestion, Chris. I shall give him a try.

Update: sadly,  he has none at the moment.

Jamie

[andrew34ruby]

A few photos of the damaged one might help in deciding how/if it can be repaired.

[Jamie]

These pictures show the self-inflicted damage.
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  Screenshot 2025-05-28 082632.png (Size: 143.85 KB / Downloads: 337)

Failing a replacement part, my thoughts are to either:

• get the melted part welded up again or
  
• cut a metal plate to the same profile as the part and have it welded to the casting. I can then drill an ream a new hole
  

There is a welding firm nearby that can weld castings.

However, I would welcome suggestions as well.

Jamie.

[Chris KC]

Yikes.

Where are you based Jamie?
There is Stonehurst Rally next weekend (Leicestershire) and Beaulieu A7 Rally coming up at end of June, both attract a selection of well-known A7 traders with cart-loads of parts. If you can't see the part you are looking for, talk to them. You doubtless could weld that up, but I'm no metallurgist and for my money I'd sooner find one in better shape, considering that it's a 'safety' part.

[Jamie]

Thank you, Chris.

I am in Aylesbury. It is my daughter's wedding next weekend, so I suspect that I would be a trifle unpopular were I to pop to Stonehurst. Beaulieu might be an option, though. I shall check the date.

Jamie.

[andrew34ruby]

Rather than build up with weld, I would cut off the damaged bit and make a new piece to weld on. Extend to a point part-way up the original section. In my rough sketch blue is original metal and red is new metal.

   

[Reckless Rat]

Personally I'd rather replace the part. It's a critical part of the braking system and if it's going to fail it will be in extremis, when you really need it not to. If this is cast steel then it will need a welding specialist to do a "proper job" on it, using stellite rods and heat sinking.

[Jamie]

Sorry to hear that Jamie. Have you tried Tony Leslie (Holmesdale Sevens)? I should have thought he could find you one.
https://oldcarservices.co.uk/austin-seven-specialists/

Personally I'd rather replace the part. It's a critical part of the braking system and if it's going to fail it will be in extremis, when you really need it not to. If this is cast steel then it will need a welding specialist to do a "proper job" on it, using stellite rods and heat sinking.

I have been in touch with a local welding firm who have advised against welding mild steel to it because of the problems that that can cause. They are talking about using specialised rods, which is encouraging. However, I confess that a replacement part would be preferable.

Jamie