Need help with "vintage" caliper brakes

[Tricycle Rider]

Right, I'm at my wits end with these - can they be repaired, or should I just replace them?

They keep on moving back and forth no matter what I do (there's a strong possibility I'm doing things wrong), but ultimately, I actually hate the whole design of them.

 

[JackRabbitSlims]

here is a nice yt clip with a basic over view on the side pull brake adjustments necessary

https://www.youtube.com/watch?v=mjaV6z_W3pc

if you haven't already, i would completely dis-assemble the whole system, clean down and re-grease the necessary parts paying particular attention to the centre pivot attachment set up

the adjustment to get the brake correctly aligned will happen there
if you have bent parts or stubborn bolts that won't allow the fine tuning......it will be a pia

difficult to tell from that pic, but make sure you don't have too much toe-in on the pads

 

[ray j willings]

Right, I'm at my wits end with these - can they be repaired, or should I just replace them?

They keep on moving back and forth no matter what I do (there's a strong possibility I'm doing things wrong), but ultimately, I actually hate the whole design of them.

If they are not siting tight then there must be space/gaps which is why the movement is happening. Look to see where the movement is. Get someone to pull the brake so you can see exactly what is going on.
If nothing is bent then its just a case of getting a nice tight fit so the only movement comes from the calliper being pulled by the cable. If they cannot be tightened maybe a worn thread? You can use a washer to fill out the space so they will tighten.

 

[JayKosta]

The center 'pivot bolt' should not move when the calipers open/close. And the calipers should be able to move freely independent of each other.
My guess is that the arrangement of washers is wrong and causes the calipers to bind with the pivot bolt when the cap nut is tightened.

If the front brake works OK, use it as a guide on how the rear should be assembled.

Jay Kosta
Endwell NY USA

 

[Tricycle Rider]

Thank you all for your help, think I might have been missing a new washer (or three).

Ultimately, though, the design of these brakes is so upsettingly asinine I wouldn't even know where to begin or how to describe it.

Anyhoo, the brakes will do for now, at least I feel somewhat safe now riding this oldie but goodie bike. (If nothing else the frame is still good.)