hard brake pedal / lack of turbo pressure

[TomTom94]

hi guys, before I start i'll point out that my Superb is a 2002 2.5 tdi with the manual gearbox

on Saturday night I was doing my usual driving when a complete racer boy idiot come flying out a junction in front of me forcing me to perform a textbook emergency stop. Now the skoda performed it perfectly. But since stopping I began to pull away immediately noticing a lack of low down power. usually from 1100 rpm up I can smoothly rev up the range but not now it sits at the low 1000's for ages even with the pedal flat and then it appears the engine picks up a little bit of power around 2100rpm where the engine sound suddenly sounds a lot more V6 and a little less john deer.

After pulling away from this I was only about quarter mile from my destination and it was when I went to stop that I had noticed the brake pedal had become rock hard as if I had pumped the brakes without the ignition on. Now I expected it would simply correct itself after a few stop starts or even disconnecting the battery over night to reset any electrics that may be playing up but nothing. no obvious problems under the bonnet, and there are no engine management lights. I've had one of my mates plug the car in to check what it reads and he responded with something I didn't understand but along the lines of the engine is under almost full load just idling where he would expect it running around 10-20% he had readings nearing 85%. I dunno what that meant or if it was unrelated.

But if anyone has any idea or experience on this it would be greatly appreciated as currently im the blind leading the deaf..

[moley]

As the brake pedal is 'hard' I would start by checking to see if the brakes are binding. How easy is it to push the car in neutral with the handbrake off?  

[rwbaldwin]

You almost certainly have a vacuum leak - check the hoses.

[TomTom94]

As the brake pedal is 'hard' I would start by checking to see if the brakes are binding. How easy is it to push the car in neutral with the handbrake off?  

 

 

The brakes have been checked and there is no signs of binding as in neutral without handbrake you are still able to move the car. and

 

You almost certainly have a vacuum leak - check the hoses.

 

As for the hoses which ones should I check as I have had a quick look and cant spot any obvious signs of a leak.

[Danny 57]

I also think that there is a vacuum leak.

[rwbaldwin]

You have lost servo assistance for the brakes and the vacuum to the N75 valve for the turbo. Does it shudder when you switch it off? Start at the vacuum pump. It's possible that the hose has come off the pump or there is a leak between the pump and the non-return valve.

[TomTom94]

You have lost servo assistance for the brakes and the vacuum to the N75 valve for the turbo. Does it shudder when you switch it off? Start at the vacuum pump. It's possible that the hose has come off the pump or there is a leak between the pump and the non-return valve.

 

it does shudder a bit a think I haven't drove the car since as I refuse to drive it with such little braking capability. Where do I find the vacuum pump? Would that be attached to the pipe coming through the bulkhead on the other end it runs past the battery and connects to the servo?

[TomTom94]

could this possibly mean the servo is broken and causing the leak or would it more than likely be a pipe? :think:

[rwbaldwin]

could this possibly mean the servo is broken and causing the leak or would it more than likely be a pipe? :think:

It's not unusual for water to get in the plenum chamber and rust out the servo. I can't remember the exact configuration of the non-return valves in the AYM, but I would hope that you wouldn't lose vacuum to everything if the servo is leaking.

[TomTom94]

It's not unusual for water to get in the plenum chamber and rust out the servo. I can't remember the exact configuration of the non-return valves in the AYM, but I would hope that you wouldn't lose vacuum to everything if the servo is leaking.

Okay I will have another more thorough look at the pipes to see if I can find the culprit. Hoping it is a simply hose leak as it will save the servo needing replacing

[TomTom94]

 

here is how my engine is at the moment. I have removed anything that gets in the way in order to see what I need to get to. I am yet to work out which pipe is the culprit.

[CRC]

Might be worth having a read of this thread ....

 

 

http://www.briskoda.net/forums/topic/157077-brake-pedal-turned-hard/

[TomTom94]

right I have had a local garage that my mate works for have a poke around at the engine as two of their mechanics are well experienced with VAG diesel motors and knew quite a bit about the 2.5 TDI.

Upon testing the vacuum in various places and what not they managed to work out that it is definitely the servo causing the problem as when the servo is disconnected from the vacuum circuit and the pipe blocked off the pressure in the rest of the circuit returns to normal and I regain turbo function instantly. so it is clear that the servo is the cause of the leak.

Now my next task is finding the part number for a replacement servo as the current one has a label on it which I assume would show the part number but sadly it is in a sorry state and no longer readable.

[rwbaldwin]

...they managed to work out that it is definitely the servo causing the problem...

That's a shame, as the servo is a bit of a pain to replace.

Can you see if it is ATE or Lucas?

Make sure you clean out the drain holes/remove the grommets.

[TomTom94]

drain holes are all clean and grommets already removed. and I will check in a moment to see what I can work out about the servo in situ. :think:

[TomTom94]

I got quoted £730 all in for the local skoda stealers to replace my servo..  

Or my local garage can fit one for £195. But supplying the servo myself.

So on top of this I have been quoted just over £200 for a new aftermarket servo from a reputable supplier. Or I can get a OEM one from Skoda for £360.

[rwbaldwin]

I got quoted £730 all in for the local skoda stealers to replace my servo..  

Or my local garage can fit one for £195. But supplying the servo myself.

So on top of this I have been quoted just over £200 for a new aftermarket servo from a reputable supplier. Or I can get a OEM one from Skoda for £360.

Don't supply the servo yourself. Get your indy garage to supply and fit the genuine part. IIRC, whichever part you need, the retail price incl VAT is less than £300. If your indy buys the OEM part from TPS (or even the dealer) it may be less.

If the garage supplies and fits the part and it goes faulty, then they are liable to supply and fit a new one.

If you supply the part and it goes faulty, then you would be liable to supply and fit a new one.

[TomTom94]

Don't supply the servo yourself. Get your indy garage to supply and fit the genuine part. IIRC, whichever part you need, the retail price incl VAT is less than £300. If your indy buys the OEM part from TPS (or even the dealer) it may be less.

If the garage supplies and fits the part and it goes faulty, then they are liable to supply and fit a new one.

If you supply the part and it goes faulty, then you would be liable to supply and fit a new one.

 

okay thanks for this. i'll have a word with the garage in the morning to see what we can work out

[dohertyjj]

before yoou go buying a servo unit check to steel pipe coming out of the vacum pump it connects to a rubber hose that goes to the servo unit this steel pipe is squeezed with a flange to the vacum pump and works its way loose to repair just put a bit of apoxy glue pushed into the seam and before it hardens tap the joint tight again if it is the servo unit the 05 reg passat has the same servo