Volvo 1800 Brake system

The chassis number matters more than you might think on an 1800. The earliest P1800 had a single-circuit brake where one leak emptied the entire system, while new brake calipers, linings and discs at the front plus wheel cylinders at the rear arrived as early as chassis #7000 (1963). From MY1966 (#16500) the rear wheel cylinders were enlarged from 3/4" to 7/8", and dual-circuit brakes were introduced in MY1969 (#28300). The 1800E from 1970 (#30001) was the first with disc brakes all round – which is why it is important to match parts to the correct model year.