PDWA or not?

[Cinbearcat83]

I am making progress on the braking system of my +2 (US - Federal). I am not reinstalling the servos. As I fabricate new brake lines, I am interested in hearing opinions on whether to reinstall the PDWA. I have seen elsewhere on the forum, that others have deleted the PDWA. I appreciate your thoughts. - Kevin

[Elanman99]

For the uninitiated, what is PDWA?

Knowing what it is might result in some replies.

Ian

[JonB]

Search is your friend...

From search.php?keywords=PDWA&t=34304

There is also a thing called a PDWA (pressure differential warning activator) which is located between the pistons on many tandem cylinders, its purpose is to light up the brake warning light if there is a failure in one circuit..

[2cams70]

This will have been originally fitted because of it being a regulated design standard. Technically you’ll therefore be making the car illegal by deleting it. Whether any inspector notices or has any idea of what the original specification was however is entirely another question

[Cinbearcat83]

In my state of Michigan (USA), there are no inspections on vehicles, so I have the freedom to delete it. I was curious if others thought it was worth reinstalling it. The previous owner removed the unit and cut the leads to the electrical sensor when he was restoring it. The unit was in a box of parts when I received the car. - thanks, Kevin

[2cams70]

In my state of Michigan (USA), there are no inspections on vehicles, so I have the freedom to delete it. I was curious if others thought it was worth reinstalling it. The previous owner removed the unit and cut the leads to the electrical sensor when he was restoring it. The unit was in a box of parts when I received the car. - thanks, Kevin

Whether you have inspectors or not isn’t related to whether the vehicle is legal or not. That part was a regulated design feature required to be fitted for the car to be allowed to be sold and distributed when new. Deleting it now technically makes the car illegal. Since it was originally regulated for safety reasons it is not something I’d be deleting personally speaking. Whilst deleting it may not have a direct affect on you because you know of the modification it may effect future owners further down the line.

[The Veg]

I'm not aware of anyplace here in the USA that does any safety inspection* more stringent than making sure that all the lights and signals and horn and such work, and that the vehicle has bumpers and wipers and all that present and accounted-for. Very basic stuff, nothing like an MOT.

So does deleting the PDWA make the car illegal? Probably (I'm not sure what the law specifically required but I've seen other types of 'brake failure' lights in other cars of the general era), but the chance of actually getting into any trouble over it as about as great as the chance that elephants will spontaneously charge from my nose.

The up-side of removing the PDWA is that you now have a warning-light on the dashboard available for whatever other function you wish to use it for.

*The majority of states do not do any inspection.

[Cinbearcat83]

I currently have it installed and am working through brake line leaks I discovered while bleeding the brakes. I am unsure if the electric sensor is operational since the previous owner cut the wires when disassembling the brake system.

[2cams70]

I'm not aware of anyplace here in the USA that does any safety inspection* more stringent than making sure that all the lights and signals and horn and such work, and that the vehicle has bumpers and wipers and all that present and accounted-for. Very basic stuff, nothing like an MOT.

So does deleting the PDWA make the car illegal? Probably (I'm not sure what the law specifically required but I've seen other types of 'brake failure' lights in other cars of the general era), but the chance of actually getting into any trouble over it as about as great as the chance that elephants will spontaneously charge from my nose.

The up-side of removing the PDWA is that you now have a warning-light on the dashboard available for whatever other function you wish to use it for.

*The majority of states do not do any inspection.

It's my day job to understand vehicle regulations and be involved in their creation and implementation for new and future vehicles. You are making the vehicle illegal and less safe by deleting that feature. It would have been mandated under FMVSS when the vehicle was new. Whether you can or should delete it is entirely for the owner of the vehicle to decide. I'm just the messenger.