L320 sport brake fade servo?

Evening everyone !
So im hoping someone can shed some light onto this and point me in the next check .

2006 l320 sport 2.7tdv6 auto

Brakes fading .. can be driving along brake and its fine and then they just give jn on me and I have to shove like he'll to get it to stop . First I thought servo however this was replaced approx 2 years ago so I did the pedal test . Car off pump pedal till hard then engine on and pedal lowered slightly.

I've bled all the brakes today and changed the fluid as the old stuff waw a horrible deep dark orange .

The pedal is hard in some ways but I can shove it down to the bump then it comes back again could it be servo ? I've disconnected pipe on servo whilst running and the pressure is relased so is under pressure.

I when stationary the pedal doesn't seem to spring like it used to and spring back up .

Sorry for babbling I'm just trying to explain it lol

Sounds like servo problems to me

Did you follow the correct bleeding procedure?

Sorry I don’t have access to my files at the mo so can’t advise what that is.

@gstuart help mate

J

marjon said:

Did you follow the correct bleeding procedure?

Sorry I don’t have access to my files at the mo so can’t advise what that is.

@gstuart help mate

J

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If there was air in the system somewhere, the pedal is unlikely to be hard?
Or could be a master problem?

kermit_rr said:

If there was air in the system somewhere, the pedal is unlikely to be hard?
Or could be a master problem?

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Yeah but if the pedal can be pushed to the stop?
That to me is air especially after a fluid change. First port of call. Although it shouldn’t get air in just changing fluid.
But need to establish.
But if the servo (been changed) is good
It has been bled correctly. Then we can move to more expensive bits

J

I used a non return valve into a bottle of fluid stared nsr osr nsf osf . Before that I sucked out as much as I could without going too low of the reservoirs and topped up with fresh fluid . It's got brembo front calipers so I bled the corners in turn starting with the inside nipple first then the outer

If you've got 2 nipples per caliper then i would expect to follow the standard 'farthest first' principle, ie bleed the side that doesn't have the oil line first.

kermit_rr said:

If you've got 2 nipples per caliper then i would expect to follow the standard 'farthest first' principle, ie bleed the side that doesn't have the oil line first.

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But it probably won't make much difference

I just did a quick search whilst under the car and it came up with inside first if you have 2 nipples on your caliper .
It's really strange . I can be doing downhill or even slowing at a junction . Press the brake and it starts fine then jist released but the pedal stays where it is . It's like a pressure released under my foot then I have to press hard on the now softer pedal to get it to stop at that point it doesn't stop sharply . It's like shoving hard on brakes coated in oil ...

I really thought servo at first but gave it benefit of doubt being only a couple years old so went for the fluid change . Tested last night and was guttered oh well at least we have new fluid

Remove the non return valve fitting from the servo, then using a cable tie as a dipstick check for the presence of oil in the servo.
There was a recall and the modified cars had extra pipework, some had new servos as well, and to top it all some of them went wrong again!
I think this was only a 2.7 v6 problem.

lynall said:

Remove the non return valve fitting from the servo, then using a cable tie as a dipstick check for the presence of oil in the servo.
There was a recall and the modified cars had extra pipework, some had new servos as well, and to top it all some of them went wrong again!
I think this was only a 2.7 v6 problem.

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You know when I was saying I disconnected the connection on the servo pipe to see of it had pressure there was a little oil on my finger ammeter covering the hose I'll have another look later !