Evening gents,

I have an issue with my 06 4.2SC.
I changed the front discs and pads about a month ago for replacement mintex items and all has been well until now whereby the brake pedal feels like it travels along way and is really firm towards the end of its travel. It feels like it isn't power assisted? I've tried pumping the pedal with the engine off then starting it up to see if the pedal depresses but it only depresses a tiny amount??
The car does stop but at slow speeds you find yourself applying loads of foot pressure to get the car to stop. I suspect maybe a vacuum leak and tonight managed to have a quick look but it was getting dark. Am I right in thinking the vacuum pump is next to the ABS pump? I disconnected the vacuum line from the pump and it doesn't appear to be doing anything?? Should it be running constantly??

Any help would be excellent.

Can somebody confirm that the vacuum pump ( small cylinder attached to the side of the l/h inner chassis leg,as you look at the engine that the vacuum line runs to) should be running constantly?? As mine is doing nothing??

Has nobody out there had any issues with servo or vacuum failure? Looking on the net it appears common on the RR sport? These I believe used the same setup as the 05/06 l323 fitted with brembo brakes? I believe there was a recall to replace both servo and master cylinder??

Sounds like a Servo/vacuum issue, unfortunately I have no additional knowledge to assist, sorry  Regards
Royston

2008 4.2 Supercharged Autobiography
1994 Classic Vogue SE
1999 Rover BRM
1987 Rover Vitesse Twin Plenum

I might be wrong but does the petrol engine have a vacuum pump, petrol engines usually have enough vacuum available to operate the brakes. Vacuum pumps are fitted to diesel engines due to lack of sufficient vacuum and then are fitted directly to the engine block to receive a drive mechanism.
The small cylinder you refer to is probably a pre-charge pump for the braking system.

" The pre-charge pump is located adjacent to the brake servo on the inner wing (handed).
At low brake fluid temperature the pre-charge pump removes back pressure from the master cylinder, sucks fluid from the reservoir and adds it directly into the circuit. The pump is always used for DSC, HDC and ETC operation and is controlled by the ABS ECU."

Hi there, the pump fitted is 100% only connected the vacuum pipe from the inlet to the servo. I suspect it is a vacuum pump as they are listed on the net for sale as vacuum pumps fitted to late model sc l322 and 405 sport.

I'm up for changing the servo as I have another car that does not have servo assisted brakes and the brakes now feel similar hence my suspicions that the servo is at fault.

The vacuum pump does not have any power to it put I don't know wether it needs to detect that the car is moving before it comes on? I can't imagine the pump is constantly running?? I'd imagine just at low rpm??

Any advice welcome??

Had a look through the manual and it does seem no vacuum pump is fitted to the earlier petrol engines, only to the diesel versions. On the diesel the vacuum pump is fitted high up on the front end of the engine block. What the item you describe is I'm not sure, nothing is shown in the manual.
With regard to your pedal and it's excessive travel, if there is no vacuum available the pedal would be very solid and a great deal of effort would be required to press it to slow the car. A pedal that travels a long way before becoming firm suggests to me either a brake fluid leak, no fluid or leaking seal(s) in the master cylinder or wheel cylinders.
Have you checked the fluid level in the reservoir?.
Have you checked for any leaks under the car? Try pumping the brake pedal a few times and then look at each wheel position and generally under the car.
Bear in mind if the brake fluid level does or has dropped without any signs of leakage anywhere the leak could be into the brake servo from the master cylinder seals.
Pumping the brake pedal with the engine off would deplete any vacuum in the system, then starting the engine with the brake pedal pressed would result in the brake pedal dropping only a small amout as you would have no vacuum assistance, exactly as you describe.
It's also worth a quick look at your brake pads to see if they are as you fitted them, I once had pad material break away from the backing plate of a brake pad with interesting results.
Personally from what you describe I would be inclined not to drive the car but if you do can I ask that you don't drive behind me.

Hi there, I have attached a pic of the pump,fluid hasn't moved in the reservoir and all calipers, lines etc appear dry? The pedal when pressed works fine and slows the car as it normally would, its just the last amount of travel that would actually stop the car feels vague and you really gave to apply force? There is vacuum present at the servo. The discs and pads are genuine brembo, it maybe feels the same as a cheap set of pads that have no bite? It's strange and hard to diagnose without changing things one at a time. I'm going to get the pads out later and see if they appear glassed. It's strange there's been a
Recal for the 405 due to a similar sounding issue?? Car doesn't pull to the right or left when stopping so I don't believe I have seized calipers.

Click image to enlarge

Well I can honestly say I have no idea what that pump is.
When you are looking at the calipers it might be worth checking that all the mounting bolts are still tight.

Have checked vacuum pump and it is working if I connect it straight to 12v. I need to find out if this should run all the time as there is no voltage at the plug with the engine running and in drive?? Took it out for a good test run and managed to get the engine management light on under heavy breaking? I will get the Gap tool on it tomorrow but I'm wondering if it's got a vacuum leak that I have missed or havnt found yet??

Has anybody got a definitive answer as to when the vacuum pump should run? I'm getting a lack of power assistance until manifold vacuum kicks in. Think I may also have defective non return valve on vacuum pipe. Previous cars:
S-Max 2007-2013 (only diesel I've had, good car but expensive when diesely bits go wrong, so what's the point?)
Galaxy 2001-2007
Mondeo Estate 1997-2001
Sierra Estate 1993-1997
Uno Turbo 1987 -1993
Fiesta 1984 - 1987
Fiat 127 1982 - 1984

Non return valves OK. Still don't know when the vacuum pump is supposed to work. I may be getting used to the wife's JCW hatch stopping on a sixpence, it's less than half the weight of mine and the front discs are enormous. Previous cars:
S-Max 2007-2013 (only diesel I've had, good car but expensive when diesely bits go wrong, so what's the point?)
Galaxy 2001-2007
Mondeo Estate 1997-2001
Sierra Estate 1993-1997
Uno Turbo 1987 -1993
Fiesta 1984 - 1987
Fiat 127 1982 - 1984

Found this to be interesting. I'm guessing that the one on my SC is the controlled variant.

https://www.hella.com/techworld/uk/Technic...pump-53588

I will assume the next step is to rig up a 12v supply and see if the vacuum pump works. A bit concerned that getting no faults with system. Previous cars:
S-Max 2007-2013 (only diesel I've had, good car but expensive when diesely bits go wrong, so what's the point?)
Galaxy 2001-2007
Mondeo Estate 1997-2001
Sierra Estate 1993-1997
Uno Turbo 1987 -1993
Fiesta 1984 - 1987
Fiat 127 1982 - 1984