PDWA Valves

[Pete Lewis]

this is fitted to many 2 line brake systems to warn you of any pressure loss in one circuit which wont be felt on the pedal as loss

 

many are disconnected, not a very bright idea , but having to connect one up today thought this may be usefull

the spool valve inside is available as a fairly cheap repair  kit  eg robsport sell for £5.7 on ebay complete valve go for silly money

theres little to go wrong apart from O ring failure , so rebuild is a very viable option.

todays  valve is fine just historic disconnection and no harness, which was acquired after much searching, it wont fit , so remove /unscrew switch

the terminals are folded over, so after some poking and twiddling the twin terminals pull out easy, its got two pins siamesed to a central terminal sleeve

so some simple straightening and refit test shows we have a operational switch ( only one terminal is used )

but the warning lamp has been jockeyed into the oil pressure switch , cut that off and run a single earth from lamp to pdwa and its all working fine 

with the valve in situ on a spitfire you need a very slim 3/4" af to unscrew the switch if needs must, it will only leak fluid if the seals have failed.

Pete

 

[Herald948]

As originally fitted at least on the North American cars with dual braking circuits, the PDWA and oil pressure warning light interconnection was an easy and cheap way to provide a bulb check on startup. The ultimate value of that might be debatable, but at least it didn't involve 30 extra feet of wire and three fuses all overseen by a CPU and requiring the services of an EE to diagnose.

[DerekS]

There was an article in the Courier a number of years back describing how to separate the two warning lights and, on the 1500, how to incorporate a handbrake warning light. Easy peasy and well worth doing as the oil light can actually be seen now.

[Pete Lewis]

Thats a good thought, the link to the oil sw was very hammy, ,

I had concern about bulb test , in my past it was linked to courtesy lamp

So oil sw is a good alternative,  reckon it will get reconnected,

Pete

[DerekS]

Btw, the article I mentioned was in the June 2004 magazine, page 63, titled "Dim Lights" .

[Pete Lewis]

 Derek,      just re read that  .............. Dim  lights    ha             not dim wits