The pistons on the left rear caliper on my 72 Bavaria were stuck so I managed to get them out for a cleaning. turns out the reason they were stuck was a rust ring at the lip of the bore which wouldn't allow the piston to move. Fortunately the pads were almost new with no wear so the pistons were nearly in their full compressed postition. While the pistons were out I noticed what appears to be valving at the bottom of the piston. I've taken a few calipers apart but never noticed valving pistons. Any information on what this apparent valving is and how it works.
rear caliper pistons
- Thread starter bavagain
- Start date
Wild speculation here - my coupe has a proportioning valve in the line that goes to the rear brakes, which diminishes the hydraulic pressure above a certain threshold to prevent the rear brakes from locking up before the fronts. Perhaps these valves you found are some type of pressure release mechanism to prevent rear lock up, which is very hard to control.