Brake Flush - Clogged Caliper?

[ScottNH]

Yesterday, I set up to flush the brakes in my daughter's '03 A4 Quattro. No braking problems, but the car has 154K on it, and I don't know if it's ever been done; or at least I can't find the last time in the service records for the car.

One man flush, using one of the Schwaben Pressure Bleeders (hint: go Motive next time). Pentosin B000750M2. Something pretty green in the master cylinder to start.

10-15 PSI on the pump, and the right rear caliper bleeds slowly, but finally changes color. (Damn you, DOT, for outlawing blue fluid). Check the PSI and hit the left rear. Open the bleeder and...nothing. Couple of drips. Open it some more. Few more drips. PSI is holding. Fluid in the tank is full. Open some more...and some more...and it's almost falling out...drips and draps, but no "gush" of fluid. Thinking it might be A LOT of air, I wait and wait. Nada. Worse than an old man at the urinal.

Rotor and pad look normal.

I'm losing daylight, so I close the bleeder and move to the right front and then the left front. Both bleed/flush fine.

So, I'm not happy. I'm thinking I'm looking a clog in that brake line, probably somewhere in the caliper. Sound right? Best course of action to remove the caliper and rebuild? Am I missing something obvious?

Thanks.

[waterguy]

I'd start with new brake lines then caliper rebuild. Take the brake line off the caliper and pump the pressure up to see what you get. Could even be the bleed screw, but I doubt it.

[UofU_USP]

im assuming if you disconnect the line to the caliper itself and the fluid comes out much faster than it would at bleeder, then yes clogged caliper. I would visually inspect the lines to the rear, metal included to make sure you don't have a bind or pinched line. You can also try removing the bleed screw all the way as well. Gonna be wasting some brake fluid though, good luck!

[ScottNH]

im assuming if you disconnect the line to the caliper itself and the fluid comes out much faster than it would at bleeder, then yes clogged caliper. I would visually inspect the lines to the rear, metal included to make sure you don't have a bind or pinched line. You can also try removing the bleed screw all the way as well. Gonna be wasting some brake fluid though, good luck!

I already had the bleed screw all the way out, thinking it was a bad bleeder, although I've never seen one.

I'm going to have to pull the brake like at the caliper and troubleshoot the clog. I'll also inspect for pinched brakeline.

Maybe it's time for some new "exact fit" stainless steel. Let's hope that's it. Be a lot less hassle than rebuilding a caliper.