View Full Version : Spitfire spitfire mk3 '70 brake pressure switch pdwa

06-29-2006, 03:53 PM
- redone brakes, front and rear...rear brakes had not worked for a long time. brakes are now excellent but can not get rid of brake warning light...i guess it is something to do with brake pdwa switch...any ideas on how to fix ?

Andrew Mace
06-29-2006, 05:04 PM
Paraphrased from the factory workshop manual:

* Fit a rubber tube...to a brake bleed-screw at the opposite end of the car to that which has just been bled.

* Open the bleed-screw.

* Switch the igntion on but DO NOT START THE ENGINE. (The brake warning light will glow but the oil warning light will remain extinguished.)

* Exert a steady pressure on the brake pedal until the brake light dims and the oil light glows (A click should be felt on the pedal as the shuttle [in the PDWA] returns to its mid-position].

* Tighten the bleed-screw.
NOTE: If the pedal has been pushed too hard [or the wrong side of the system was bled] the shuttle will move to the other side of the valve, thus requiring the procedure to be repeated on a brake at the opposite end of the car.

Some folks clamin success by undoing the sender for the light from the PDWA, and then manipulating the shuttle with a screwdriver. I prefer this method. It takes a bit of practice to "feel" what happens, but you'll know it when you feel it.