[Fot] TR-6 Brake Servo

[Gary]

Hello:

I need some advice on the probable solution to a brake servo problem that just
popped up.  This is for a stock 1969 TR-6.  Symptons:

1.  When pressing the brake pedal, I hear a soft "whooshing" sound which
occurs whenever I pump the pedal.
2.  The brake pedal requires more pressure.
3.  The engine speed drops rapidly as long as there is pressure on the brake
pedal.

All this leads me to believe there is a leak in the brake servo unit.  Looking
in the service manual reveals that only a filter at the brake pedal end of the
servo can be replaced.  However, the Moss catalog shows the non-return valve
and a seal & plate assembly are availalbe but no filter.  The Victoria British
catalog shows a repair kit but no description so not sure what is included.
Any thoughts on which or both of these parts could fix the problem?  If I
remove the rubber hose from the brake servo unit (which leads to the intake
manifold) and temporarily block it off, will that alleviate the problem?
Thanks.

Gary
62 TR-4
69 TR-6