Alfa Romeo, Automobile Work, Automobilia

Alfa Romeo – Sticky ATE Brakes


The front right brake on the Giulia Super began sticking just a couple of weeks after the drive from Connecticut to Florida. When braking, the car would pull to the left. After a drive I noticed the right front wheel was very warm and wheel would not rotate freely. This is the tell-tale sign that the brake caliper has become non functioning due to the internal pistons becoming stuck in the bore.  Removal of brake caliper revealed that the outside piston was at fault as the inboard side of the caliper was able to be pushed in.  The caliper was removed and work began on freeing the stuck piston. The rubber dust cover was removed and WD-40 was sprayed around the shaft of the piston and allowed to work in overnight. Then the caliper was reinstalled without the brake pads and some wood shims were inserted in their place. Then the brake pedal was pressed to force the pistons out. After some hard pressing, the stuck piston released and moved out.  A thinner shim was then inserted and the peddle was pressed again forcing the piston farther out.  Another night of soaking with WD40 followed then the pistons were dried and brake grease was applied to the pistons and they were pushed all the way in by hand. Dust cover re-installed and calipers mounted on the car.  Speed-bleeders replaced the all the old bleed valves on this and the other calipers. The brake fluid was completely flushed with new. A test drive pointed to a successful repair of the brake system.

The lesson learned here is brake fluid used in these older cars (DOT-4) absorbs water over time. Water causes rust and the brake pistons get rusty and stick to the metal of the caliper. To avoid this, change the brake fluid yearly.

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