Is the PDWA selt-centering?

[TR6BILL]

I am in the process of replacing all four of my rubber brake hoses from the frame to each wheel with new braided hoses (Whew! They are proud of those things!) I cut the rear hoses and let the brake fluid drain out of the rear lines (Weelll, not exactly. The wife pumped the brake a few times. Prolly shouldn't have done that.) Will cut the front next when the car goes back up in the air. (Still trying to finish the TAs and need to do some guess-shimming before taking her down the road to the alignment shop.) Time to replace all my old brake fluid again. (Yes, I am still using Castrol LMA Dot 3. I have a love/hate thing with paint.) Anyway, because she pumped the line a bit, did the PDWA go off center? And the big question is, will it self-center after all lines are back in and new fluid is placed? Will do the traditional de-bubbling at the furtherest drain point and so on...

 

[PeterK]

You will probably need to pull the switch and center the PDWA valve. But it's a good time to check and replace the o-rings anyway once all the fluid is out.

 

[TR4nut]

Bill-

You don't necessarily need to pull the switch, but it helps if you know which side might have been at low pressure. I did this before on my 6, and I was able to recenter by opening up the bleed valve on the other system and pumping until the light went off.

Randy

 

[Brosky]

These switches are simple to repair and worth the effort after 30 plus years.

PDWA Rebuild

 

[DrEntropy]

Agreed. And I've had the diabolic things 'toggle' back and forth trying to center 'em with just pressure. If you go thru it and then center it 'manually' one time it should be good for another decade.

 

[Andrew Mace]

FWIW, simply "because she pumped the line a bit" wouldn't necessarily disturb the PDWA. It usually takes pretty good amounts of pressure to "trip" the switch.

 

[TR6oldtimer]

Bill-

You don't necessarily need to pull the switch, but it helps if you know which side might have been at low pressure. I did this before on my 6, and I was able to recenter by opening up the bleed valve on the other system and pumping until the light went off.

Randy

I have used the same technique. Once you convince the wife to get under the car with a wrench on the bleed valve, the procedure works well. Resetting it through the switch also works and allows you to see if it is leaking.