Servo fault

Hi Guys
Got a 52 plate 19tdi 115 pd sharan. about 85k on clock.
A few month back my other half complained that the brakes suddenly failed. It only happened once. Had a look around it and decided she probably just hit a greasy or dirty bit of road or something. No sign of it happening whenever I drive it
That is until last week while in France, loaded with holiday clobber and kids, and the bike trailer on the back. Driving round a Super U car park and suddenly no servo assistance. Picked the revs up and it returned. This continued to happen occasionally over the holiday, but it only seems to happen at low engine revs, and after repeated dabs of brakes, IE as in driving round a car park looking for a space.
If I sit at traffic lights and repeatedly apply the brake, the servo assistance diminishes unless revs are picked up from tickover.
Now I am quite an experience engineer(grew up in motor trade, dad had garage in Luton for 20 years) and Yes I know I shouldn't be using it with such a fault.
So My question to you guys is - Is this a common fault? Do the servo's die at 80k, or the vacuum pump? Or is it just the pipe between them splitting?
I had the engine apart before the trip to change the cambelt(due at 80k), but had been given the wrong kit, so its still do. So I will be looking to see if I've upset something, but I'm looking for any advice/pointers for what else to look for.
Thanks in anticipation
Hugh.

either the exhauster pump or the vac pipe

Thanks for the reply towcestervag.
By exhauster pump do you mean what I know as the servo vacuum pump, located on the end of the camshaft above gearbox?
Nice to see you don't think the servo itself, wouldn't fancy changing that...

yes the pump on the end of camshaft
i dont know if you can get a seal kit fot it but its worth a scout around to see
i have had the one way vac valves in the vac line fail shut but this usually happens in cold weather

You sound like you've got the same problem I've just fixed on my 98 Sharan 109k 1.9tdi ! There is a plastic hose which connects the servo pump to the servo. It is made of a hard plastic and with time it hardens and then splits just a little where it connects to the pump/servo allowing a slight leak. At normal driving revs the leak is so small it is not noticeable but when parking there just isn't enough 'suck' to give servo assistance particularly on the second pedal stroke - quite un nerving!

I first read about these hose splits on this website - so not surprised to find that that was my problem. A week ago I wrapped pvc insulating tape around both ends of the hose to cover the splits and found things were much better but not perfect. Yesterday I rolled up my sleeves and discovered hidden out of sight near the fuel filter was a one way valve in the middle of the hose and - yes - another split at the join! I actually replaced the back piece of hose completely with a washing machine feed hose which is the right diameter for a good tight fit but stiff enough not to collapse under the vacuum pressure.

I now have brakes that work as they were meant to. Hope that is of some help.

This sounds exactly like the problem I have with my Sharan.I'll be hose checking this week!! Thanks very much for the advice.

Smither01, this is exactly what I found withmine when I pulled it all apart. Having bought a new pump from Eurocarparts in MK (£236), pulled the old one off and as I pulled it forward the hose just fell off the outlet side of the check valve thats located a few inches along from the pipe.
Have fixed mine with some 10mm copper pipe to sleeve the plastic tube and a reinforced rubber hose to join the valve to the pipe and a couple of small jubilee clips to keep it all in place. The copper sleeve is there to stop the clips colapsing the pipe.
Fortunately Eurocarparts gave a full refund on the pump, so big thumbs up to them.

Hi Dumptruck - glad you sorted it out AND got your money back on the pump! Your copper pipe solution sound very professional, it'll probably outlive the rest of the vehicle.:Blush:

Cheers lads

Had same problem with da missus 03 Sharan
Thanks to you found the split hoses straight away.
Easy fix - Nice one:beerchug:

Hi all - I just spent hours fitting the new design servo pipe to my 96 Sharan 1.9TDi. Really awkward as it seems to go behind the master cyl bracket now! Anyway, the new pipe is on but right at the last minute I ruined it! Have pushed the grommet into the servo whilst struggling to insert the pipe.

Now I have two problems - can I leave the old grommet inside the servo? and where do I get a new grommet (the local dealer says it is only sold as part of the whole servo unit!)

Any help very welcome :-)