MikeB wailed:

Pressure differential valve needs reset? No make/model....

MikeB


There's a "low-tech" way to reset those valves.

First, there's no indication whether it's the front or rear that's caused
the imbalance. That means you'll have to work on both circuits before
you get it.

Put a bleeder hose onto (say) the front, and have a helper go through the
exercise of filling the hose until there's some fluid in your reservoir
so it can't back bubbles into the system. Y'know... push pedal, crack
the valve, close the valve, release the pedal... and so on.

Once the hose and catch bottle both have fluid in them, have your helper
push on the pedal fairly hard, then crack the valve open more than just
for bleeding. Have the helper make sure they don't lift the pedal until
you close the valve again.

Now you've deliberately off-set the balance valve to the front. (front
pressure low condition).

Now go to the rear. Repeat the exercise, but SLOWLY AND GENTLY pressing
the pedal while slightly cracking the valve AND WATCHING the light. At
some really twitchy point in the pedal travel, the light will go out.
Helper hollers "OUT", and you simultaneously close the bleed.

It's worked for me a dozen or so times. Tricky, yes. You might have to
do it three or four times before you get it right.

Clue here -- when watching the light, if it blinks off then on again,
you're "past center". Then it's the other end of the vehicle you need to
repeat the operation on.

LLoyd