Hispec and PNM

[Steve A]

What does everyone do about galvanic corrosion?.. it attacks the pad pins and the bleed screws (both stainless steel..although i don't know what grade). I've had Hispec 4-pot calipers on the front for 10 years now (bought from PNM)..and the GC is biggest pain ever!.... removing the pad pins has always been a challenge.. and only luck has prevented seized bleed screws.

When I fitted mine years ago, I used copper slip in all the right places, to prevent/help with the corrosion issue.
When I changed my pads last year, I didn't have too many problem getting the pins out, although I did see some signs of corrosion once the pins were out, but the grease certainly did help. I polished the pins with fine grade wet and dry and they soon looked as good as new.

One thing I would recommend when removing the pins is to always use the correct tools.
I use a decent centre punch, just to get that initial movement of the pins, until it is flush with the calliper hole, and then a pin punch slightly smaller than the pin to finish the job.
If you use a pin punch which is bigger or close to the size of the pin, then you're in danger of bevelling the end of the pin, and then you're stuffed.

[dapinky]

Good advice about the tools to remove the pins, especially if they are stuck.

I did mine when they were off the car, and had to resort to cutting through 2 of them, removing the old pads, and drifting the bits of pins from the centre outwards.

I wrecked the outer ends with brute force to break the corrosive seal, so it was the best option at the time....... But just be careful if you plan to reuse the same pins.

As the pins are held in place with tiny "R" clips (which also break quite easily if rust gets to them), I wonder if cleaning out the bore in the calliper with a drill bit or roll of emery would actually do any harm as the pins don't need to be an interference fit like on the OE callipers.

Or maybe even an engineered solution of drilling out the calliper and fitting a suitable bush (probably a last resort due to lack of aluminium around the holes anyway).