Here's a weird one.
Took my TDV8 3.6 in yesterday for a gearbox oil hot flush and box service. When I went to collect it the brake pedal was rock hard. You need legs capable of kick starting Concorde to apply any pressure.
I thought simples, they've left a vacuum pipe off somewhere. They put it back on the ramp and checked it but found nothing. I drove it home and every time I pressed the pedal the servo worked for the first push then it was like there was no assistance on the second application.
My thinking is vacuum leak, vacuum pump or servo.
Today I inspected it all visually and it looks fine. No sign of rust on the servo. With engine running there is a vacuum at the pump although how strong it should be I don't know. Nor is there any hissing sounds of a leaking vacuum pipe.

My problem is would any the components suddenly fail without warning?

I had a look in the manual which says: In the event that the brake booster fails, the hydraulic system will still function but will require greater pedal effort due to the lack of vacuum assistance. Yup if greater effort means Fred Flintstone pressure through the floor I agree.http://www.fullfatrr.com/forum/images/smiles/icon_lol.gif

It also indicates the vacuum pump serves two other functions but no mention of any vacuum in the gearbox regions.

The Vacuum required for brake booster operation on TdV8 vehicles is provided by an engine driven vacuum pump. The vacuum pump is a radial vane type pump mounted to the front of the RH cylinder head which is driven by the intake camshaft. The vacuum pipe from the brake booster connects to an elbow on the rim of the vacuum pump.
The vacuum pump is lubricated and cooled by engine oil supplied to a port in the front face of the vacuum pump from a gallery in the cylinder head. The oil return is through a vent in the front face of the pump into a drain cavity in the cylinder head. Air extracted from the brake booster is vented into the drain cavity with the returning engine oil.
The vacuum pump is also used to supply vacuum for operation of the following components:
 The exhaust gas recirculation (EGR) system.
For additional information, refer to: Electronic Engine Controls (303-14C Electronic Engine Controls - 3.6L V8 - TdV8, Description and Operation).
 The adaptive engine mounts.
For additional information, refer to: Electronic Engine Controls (303-14C Electronic Engine Controls - 3.6L V8 - TdV8, Description and Operation).
Unfortunately I can't access the two links.

Anyone experienced anything similar? I need this sorted fast as I've very little time over the next month.

I just can't help thinking somehow its related to the box service although they drove after servicing it and found it fine then parked it till I turned up. They then tried it and agreed with my assessment. They also said they hadn't been under the bonnet.

Thanks for any thoughts. Rehab is for quitters!!!

RR 2007 3.6 TDV8 Java Black *
RR 2007 3.6 TDV8 Zermatt silver *
RR 2000 P38 4.6 Met red *
Mercedes 300TE 4-Matic *
Jaguar 420 (1969) *
Nissan 300Z
Citroen XM 2.5TD X 6
Bentley Continental R
Hydrocon Highlander
Hydrocon Hamilton
Hydrocon Huntly
Am told the ones with a * are to be offered for sale! 😳

Departed
LR 1992 110 2.5TD
RR 2000 Holland & Holland 4.6 LPG
RR 4.2 Supercharged with LPG, Vogue SE 2007 Buckingham Blue
RR 2002 4.4 V8 Zambesi Silver