fluid change

redbird 2 · Unread post by **redbird 2** » 07 Jan 2003, 23:57

I am about to change the LHM in my xantia 97 td lx and want to know if after i have cleaned the tank out and refilled with fresh LHM do i have to bleed the brakes?????????

mbunting · Unread post by **mbunting** » 08 Jan 2003, 01:02

The brakes are a dead-end pipe, so what is in there now will still be there after the change.
Therefore, it is a good idea to bleed the brakes until the bright green new LHM comes out, otherwise you're still relying on the old rubbish to stop your car !
Regards
Mat.

Dave Burns · Unread post by **Dave Burns** » 08 Jan 2003, 01:36

They ought to be bled because this also changes the fluid in the calipers and brake lines, though its not strictly necessary it is good maintenance procedure.
Drop suspension to minimum and allow to tick over for one minute, this keeps the anti-sink valves open and allows the spheres to fully discharge, then stop engine and open pressure release screw one to two turns but don't remove it.
Remove the large flexible air pipe between the air filter and the hard plastic turbo air feed duct, syphon the bulk of the LHM out, unclip the pipe bracket at the bottom/side of the tank of, you can then turn it on its side to withdraw the pipe/filter block, have a clean container ready to drop the pipe/filter block into.
When you start the engine for the first time after the LHM change, let it run for a minute with the pressure release screw (do not remove it) open, this purges the pump intake of air, returning any that has entered to the reservoir via the regulator return and power steering circuit, this prevents it from entering the accumulator, from where it could then enter the system and possibly the brakes.
Close release screw and cycle the suspension two or three times between max and min.
Dave