Re: treadle vac

Posted by Tim Cole On 2015/8/8 5:38:11

If you are a reader of these BTV threads this scenario seems to follow a pattern:

Brake pedal becomes hard followed by a sudden loss of braking with the pedal going to the floor.

There are two sources of hydraulic problems in this unit. The compensator valve and the ram seal.

A damaged compensator would cause a sudden loss were the unit to fall apart, or no brakes from the outset among other weird symptoms (low pedal, gradual lock up) if the pin is damaged.

However, if the ram seal rolls on the shaft this would cause a stuck pedal followed by destruction of the seal and total loss of braking.

My guess then is that not using a seal protector and lube during assembly is damaging these seals, or the use of a pitted ram is causing same. So I would buy the available new ram if there are any signs of wear.

Seal protectors can be had from NAPA or a local trans shop although if I were a parts supplier I would include such in the kit to avoid product liability.