Subject: Re: Brake bleeding & new question
> Nelson and List:
>
> I've been monitoring the post on brake bleeding and PDWA centering. I've
a
> question for you. I recently had the brakes serviced and bled at a local
> shop. I had them install a new PDWA switch that I had on hand. When I
got
> the car home and reconnected the ground wire from the harness to the
switch
> the brake light came on. This leads me to believe that the switch needs
to
> be centered.
>
> I've considered just removing the switch and manually repositioning the
> piston. Can this be done without introducing air into the system? Or
will
> it be necessary to rebleed the system? Any input is appreciated.
>
> Thanks and best regards,
> Walt Fogle
Hi Walt,
The point where the switch screws into the PDWA is isolated from the fluid
by seals so removing the switch should not cause air to enter the hydraulic
system. If there is fluid in the hole where the switch fits, then the
seals are leaking and need replaced.
First, I'd remove the switch and make sure that it is operating properly..
With all the wires connected, the brake lamp should be extinguished (unless
it is on because the park brake is engaged). If the brake light is on,
then there is something else wrong. If the light is out, I'd then push the
rod extending from the end of the switch which should cause the lamp to turn
on.
If the lamp & switch are operating properly, then I'd use a sharp tool to
slide the piston to the position where narrowest part is under the hole for
the switch. In the position, the rod on the end of the switch is not pushed
in when the switch is screwed in and the light is extinguished. When the
piston moves off center, the thicker part of the piston pushes the rod on
the switch thus activating the switch and turning the lamp on.
Hope this helps
Nelson Riedel
Granville, OH
76 TR6 (assembling after new paint)
68 TR250 (next project - new paint)
70 TR6 (all the parts in a pile ready to assemble)
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