How To Remove Brake Piston

Brake Caliper Piston Removal

Some of you might think of a vintage motorcycle every bit having simply pulsate brakes.  On the contrary, since the disc brake striking the market in the early 1970's, it has been a great performance upgrade to the older drum mode brakes.  Disc brakes are great until the bike sits for a long fourth dimension, when the metal housings first to rust and the fluid turns into a jelly-like goo.  Then the front brake pistons no longer move in and out or in the worst example, the brakes are frozen solid to the brake disc.  Now you lot are faced with repairing the brakes, replacing the seals and possibly the rusted pistons.

 The primary problem is getting the pistons out of the calipers.  Over the years I have seen many solutions to this problem.  Some are quite crude, such every bit drilling a hole through the caliper, pushing the piston out and and then plugging the hole with a household pipage thread plug.  This is not a good look for a restoration; it's really not even a good look for a daily commuter.

 Here is a keen way to get those stuck pistons out of the calipers.  In this instance, I used a dual piston caliper establish on the Yamaha RD's, XS's and TX's.  If you tin master the dual piston caliper, the unmarried piston caliper will be a breeze.

Some special tools are required, just they are available from any local tool and hardware shop.

1. Air compressor
2. Air blow gun with a safety tip
3. Option
4. A heat source such every bit a estrus gun or propane torch
5. Minor piece of aluminum
6. Two large hex nuts
7. C-clamp
8. Demote vise
9. Bones manus tools

 Begin by removing the brake caliper.  Once the restriction caliper is out of the bike it volition need to be taken autonomously.  Split up the caliper in half by removing the 2 large bolts and the 2 internal hex bolts.

Start with the side without the bleeder.  Advisedly clamp the caliper half in the vise so the piston is non obstructed by the jaws.  Utilize the C-clamp and compress the piston and so it bottoms out against the caliper body.  Be careful as the old fluid will be ejected from the caliper.  Remove the clamp to allow for the dust seal removal.

Remove the dust seal (the slightly exposed rubber seal) from the caliper with a pick.  This will take some patience and a little endeavor.

The primary problem with the outer-side caliper is being able to pressurize the caliper since there are two holes, i where the line hooks upwards, and one where it crosses over to the other half of the caliper.  The crossover hole will need to be blocked off.  This can be accomplished with a pocket-size slice of aluminum, 0.020 inch minimum thickness will do.  Drill two holes that line up with the two bolt holes in the caliper.  Hole placement can easily be determined by using the bleeder-side caliper half as a template.

Using the old middle caliper seal, place the seal over the crossover hole in the caliper.  Mount the block-off plate on the caliper using the existing caliper internal hex bolts and two large hex nuts.  Because the internal hex bolts are too long, the large hex nuts are necessary to tighten downwardly the cake-off plate.  Use a small-scale amount of grease to go on the seal in place while installing the plate.

After the dust seal is removed and the block-off plate is installed, place the C-clamp dorsum on the caliper merely do not tighten information technology.  I apply the clamp as a safety device for the adjacent stride and so the piston cannot fly across the shop.  Place the rubber tipped accident gun in the principal hole where the brake line attaches.  Hold the air gun firmly in place to provide a tight seal.  Slowly apply pressure; the piston should slide out under the air pressure level.  If the piston yet will not budge, apply heat to the caliper half until it starts to motion.  Remember the C-clamp is there to brand sure the piston does not go a missile.  Conform the c-clamp as needed to permit complete removal of the piston.  Likewise be careful of the erstwhile brake fluid left in the caliper as it volition also be under pressure.

In one case the piston is fully removed you lot can remove the plate and the seal and move onto the caliper one-half with the bleeder.

To remove the bleeder side piston, repeat the steps above with the exception of the block-off plate.  Exit the bleeder tight and identify the prophylactic tip of the blow gun into the caliper crossover port.  Exercise not forget the C-clench!

After the pistons are out, you are all set to go on your brake restoration.  This technique can be used on almost whatever brake caliper, single or dual piston.

Brad Obidowski

HVCcycle

Source: https://hvccycle.net/brake-caliper-piston-removal/

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