Rear caliper handbrake mounting pins

[Andy8421]

I am stripping down my seized rear calipers to restore. Reading old threads in the forum, I have managed to figure out how to remove the pins that hold the handbrake wings onto the caliper, but its not clear what actually holds the pins in place in the first place apart from rust and road dirt.

Originally I thought the pins were badly worn, but looking at an exploded diagram, the pins are supposed to be 'waisted' in their central section - so it is possible that the wings stop the pins falling out as the spring on the handbrake mechanism pushes the wings against this central section.

Any advice on how the pins are supposed to be held in place would be most welcome.

Thanks,

Andy.

[jono]

Hi Andy,

I'm at a similar stage - the pins are an interference fit via the sightly thicker section at each end.

I had to drill and tap them to M6 and use a bolt and spacer to wind them out as they were well and truly seized - I applied heat at the same time.

Jon

[patrics]

Hi,
The pins are a push fit and are held in place by the pad backplate.
Thread size on the pins is 2BA

Regards
Steve

[oldelanman]

The pins are a tight fit in the caliper body and would be unlikely to fall out but I believe once the handbrake pads are fitted the pin can't come out anyway. The slot in the pad fits the waisted section of the pin effectively locking it in position.
My pins were pretty tight but came out fairly easily using just the small bolts which secure the pad centralising brackets screwed into the existing threaded holes in the ends of the pins - no need to drill and tap larger threads. Once cleaned up and lubricated the pins were a tight push fit into the calliper but definitely not an interference fit in my case.

[Andy8421]

I checked, and the slot in the pad does indeed locate on the narrow section of the pin and stops the pin falling out. A good example of a component doing more than one job.....

Thank you all for the feedback.

Andy.

[jono]

The pins are a tight fit in the caliper body and would be unlikely to fall out but I believe once the handbrake pads are fitted the pin can't come out anyway. The slot in the pad fits the waisted section of the pin effectively locking it in position.
My pins were pretty tight but came out fairly easily using just the small bolts which secure the pad centralising brackets screwed into the existing threaded holes in the ends of the pins - no need to drill and tap larger threads. Once cleaned up and lubricated the pins were a tight push fit into the calliper but definitely not an interference fit in my case.

I was obviously unlucky!

The std threads in the pins just stripped out when I attempted to pull them that way, even with heat applied, hence having to resort to tapping to a larger size.

...I now just need to tackle how to recover ovalised holes in the hangers!

Jon

[Craven]

Simple infill of braze will work for many years.

[Andy8421]

The pins are a tight fit in the caliper body and would be unlikely to fall out but I believe once the handbrake pads are fitted the pin can't come out anyway. The slot in the pad fits the waisted section of the pin effectively locking it in position.
My pins were pretty tight but came out fairly easily using just the small bolts which secure the pad centralising brackets screwed into the existing threaded holes in the ends of the pins - no need to drill and tap larger threads. Once cleaned up and lubricated the pins were a tight push fit into the calliper but definitely not an interference fit in my case.

I was obviously unlucky!

The std threads in the pins just stripped out when I attempted to pull them that way, even with heat applied, hence having to resort to tapping to a larger size.

...I now just need to tackle how to recover ovalised holes in the hangers!

Jon

Jon, it seems I am travelling down the same road, just a few steps behind you. I was lulled into a false sense of security by the first caliper, the pins on the second one won't budge. I have cleaned the threads out with a 2BA tap, but 2BA is pretty weedy, and I think I am just about to strip the threads if I pull on the screw any harder. I have tried heat / penetrating fluid and a Birmingham screwdriver, no movement at all. Your M6 drill and tap solution sounds like the way to go.

Do you (or anyone else) know if new pins are available, and where to get them if they are?

Thanks again,

Andy.

Edit: Found them:

https://kelvedonlotus.co.uk/product/handbrake-pivot-pin/

[vxah]

What I did to get around the oval hole problem was buy new pins then, I acquired some stainless tubing of the correct internal diameter to slide over the pins. I then set up the worn parts and drilled out the oval holes to provide a slight interference fit around to outer diameter of the tube. Then using Locktite adhesive I pressed the tube right through both of the drilled holes, when set overnight I then cut the tube excess off and filed up the ends of the tube leaving me with nice bushes installed!

[jono]

The pins are a tight fit in the caliper body and would be unlikely to fall out but I believe once the handbrake pads are fitted the pin can't come out anyway. The slot in the pad fits the waisted section of the pin effectively locking it in position.
My pins were pretty tight but came out fairly easily using just the small bolts which secure the pad centralising brackets screwed into the existing threaded holes in the ends of the pins - no need to drill and tap larger threads. Once cleaned up and lubricated the pins were a tight push fit into the calliper but definitely not an interference fit in my case.

I was obviously unlucky!

The std threads in the pins just stripped out when I attempted to pull them that way, even with heat applied, hence having to resort to tapping to a larger size.

...I now just need to tackle how to recover ovalised holes in the hangers!

Jon

Jon, it seems I am travelling down the same road, just a few steps behind you. I was lulled into a false sense of security by the first caliper, the pins on the second one won't budge. I have cleaned the threads out with a 2BA tap, but 2BA is pretty weedy, and I think I am just about to strip the threads if I pull on the screw any harder. I have tried heat / penetrating fluid and a Birmingham screwdriver, no movement at all. Your M6 drill and tap solution sounds like the way to go.

Do you (or anyone else) know if new pins are available, and where to get them if they are?

Thanks again,

Andy.

Edit: Found them:

https://kelvedonlotus.co.uk/product/handbrake-pivot-pin/

I was about to direct you to SJ Sporstcars Andy but I see Kelvedon do them also.

....mine will go again so I intend to re use them

[Andy8421]

As predicted the 2BA bolt gave up the fight, but Jon's recommendation of drilling and tapping the pin to accept a 6mm bolt worked like a charm. I now have all pins out.

Drilling and tapping doesn't really effect the pins, and I could re use them, but they definitely show signs of wear where the pads fit so I will replace with new.

On examination all the holes are elongated in the various bits of the handbrake mechanism, and it did sound like a bag of spanners when I hit a bump, so I will have a go at renovating the holes as suggested above.

I will try to post some pictures of progress so far.

Andy.