whats wrong, brake hold tight after replace caliper oil seal

[Addy Leung]

Could anyone can share some exprience for barke caliper oil seal replacement.

I have disassembly the front brake calipers completly, cleaned and replaceed all new oil seals and dust seals and o' rings. all seals have applied with little rubber grease befroe install back the pistons and use the old brake pads. After bleeded the brake cylinder, the brake is very ok when testing by push the bike. But when I rided it on the road, after about 5 mins time the front brake disces were getting very hot and brake caliper hold tightly.
the bike stopped aside on the road. after about 30 mins, brake system getting cool, the brake released, then I rided it slowly back home.

What's wrong and what should I do next?

Addy

[Anonymous]

You have to clean a small orifice between the fluid container and pump in your front brake pump.
You have to holes there, the big one an the very small one which prevents pressure to be built in your braking system.

Adam M.

[ZacharyB]

You have to clean a small orifice between the fluid container and pump in your front brake pump.
You have to holes there, the big one an the very small one which prevents pressure to be built in your braking system.

Adam M.

Where is this very small hole? I have the master cylinder off my bike and I cannot find this hole in the reservoir/plunger junction. I can only find the main hole. (I have this problem too)

Edit: Nevermind. This hole is so small that I didn't see it. On the bottom of the reservoir, after it is removed, there are two small pits off to the side. One is a visible entry into the plunger section. The other is a shallow pit that seems to go nowhere. This is where the small small home is. I'd say it's about a fifth of a millimeter in diameter. Poke through it with a fine wire brush bristle a couple of times.

[Anonymous]

all seals have applied with little rubber grease befroe install back the pistons

I rebuilt my calipers last summer. I'm unfamiliar with rubber grease in the rebuild process, rubber grease seems would contaminate the brake fluid. When I rebuilt mine, I only used clean brake fluid to soak the rubber o-ring in. The rubber grease might have affected the piston's ability to move freely. This could cause the brakes to get hot.

Just a thought.