AP Racing Brakes – How To Remove Seized Pins

The Problem:
Changing the brake pads in AP Racing callipers should be an easy process, however, the retaining pins have a tendency to seize in the callipers making removal very difficult.

The Tools:
15mm socket, 12mm socket, 4mm diameter short pin punch, Flat head screw driver, hammer, large hacksaw blade.

The Fix:
Having a set of used AP Racing callipers I set about preparing them for painting. First job remove the old pads. The recommended method for this is to use a 4mm diameter short pin punch for maximum shock load and minimum force to tap the pins out. As the pins were seized and had obviously been struck many times by the previous owner, this method would not remove the pins.

For removal of callipers see this other T-Bar How To by CJJ

I cleaned around each hole then soaked both ends of each pin with penetrating oil and left for 24 hours.

The pins would still not move! :nonod:

I contacted AP Racing for advice on this problem.
AP Racing sent a prompt reply stating;

Over time the inner side of the pins involving split steel collet can seize in the alloy body.
Usual method
Remove the callipers from the vehicle.
Push out the anti-rattle clip from under the pins.
Clean the centre of the pins so that they can pass through the holes in the body.
Soak the inner holes with penetrating spray for at least 24hrs. Using a 4mm diameter short pin punch for maximum shock load and minimum force tap the pins out.
If it doesn’t move then don’t hammer to hard or the pin can bend. If that’s the case you will need to apply heat to the inner hole area to break the corrosion. A butane gas torch with a fine flame will do the job but only apply heat to the back of the hole so as not to burn the seals.
When fitting new pad; smear the split collets with a film of copper slip.

Following the advice I then used a gas torch to heat the holes at the collet end of the pins from the outside of the callipers.

The pins would still not move! :nonod:

I then decided to cut out the centre section out of the pins in order to ‘attack’ each end of the pins separately. I removed the anti rattle clip using a flat head screw driver to push the clip out from under the pins and then using the pad as a guide; used a new large hacksaw blade to cut through the pins, thus removing just over an inch from the middle of each pin.


(Obviously don't cut your callipers, just the pins. Apologies for a sloppy bit of photo editing :slapme: )

I then held the calliper in a vice and used a 4mm diameter short pin punch to remove the narrow ends of the pins. This required quite some force! :bat:

I then used a crowbar and hammer to strike the stump of the collet end of each pin to remove; this again required quite some force! :bat:

With both ends of the pins so badly seized, as was the case, simply striking the whole pin with a 4mm diameter short pin punch did nothing but mushroom the end of the pins making extraction even more difficult.



Prior to fitting the new pads I applied copper slip to the face of each of the four pistons and too both ends of the pins so that, hopefully, next time I need to change the pads the pins will come out with ease.

All's well that ends well :woohoo:

Handsaw job...
for heavily rusted ones!

I also had seized up pins and no amount of hard thrape with the hammer and punch would persuade them to budge!
I then undid the four caliper bolts that hold the two halves together and managed to crack the half with the collet ends away with some leverage. I suppose I am only moving half as much of the pin as I would be by trying to knock the whole pin out in one go.
I was then left with the other half of the caliper with the headed ends of the pin in. These tapped out ok with the hammer.

Sundance