What's this bit called?

[paulmmc]

What is the proper name for this part of the brake system from my S3? Is it a shuttle valve?

Thanks, Paul

[MudLifeCrisis]

Sorry can't answer the question but nice to see someone else from St Albans on here.
Brian

[TBM]

http://www.lrseries.com/shop/product/listing/14123/NRC4880-BRAKE-SYSTEM-PDWA-VALVE.html?search=nrc4880&page=1

Often called a Shuttle Valve but correctly called a PDWA valve. Part number NRC4880

They can cause problems when bleeding and many bypass them.

[bogie]

Far as i know it aint a good idea to bypass the shuttle valve as it loweres the pressure to the rear brakes so ur back end doesnt kick out when braking hard and if your rear brake line gets damaged it isolates the front so you still have front brakes to stop,but dont hold me on this !

[TBM]

Far as i know it aint a good idea to bypass the shuttle valve as it loweres the pressure to the rear brakes so ur back end doesnt kick out when braking hard and if your rear brake line gets damaged it isolates the front so you still have front brakes to stop,but dont hold me on this !

It doesn't lower the rear pressure but it does isolate the front or rear circuit if there's a break in a line. Bypassing turns it into a standard single line circuit like on the older Land Rovers.

[fordlltwm]

Far as i know it aint a good idea to bypass the shuttle valve as it loweres the pressure to the rear brakes so ur back end doesnt kick out when braking hard and if your rear brake line gets damaged it isolates the front so you still have front brakes to stop,but dont hold me on this !

It doesn't lower the rear pressure but it does isolate the front or rear circuit if there's a break in a line. Bypassing turns it into a standard single line circuit like on the older Land Rovers.

Nope, other shuttle valves do, but a standard LR one just switches on the light on the dash that says BRAKE, rather foolish but that's BL quality design for you

[bogie]

THIS IS GETTIN CONFUSIN! Which ones do what then???????????????????????????

[fordlltwm]

The OP's bit just switches a light on the dash that tells you your brakes a failing when theres a missmatch in front and back pressures, such as a leak

[bogie]

So basially you might as well f it off because you dont need a stupid light to tell you that your brakes are failin! You put your foot down which operates the light if they fail,but your foot would already be telling you this!