brake booster faulty

[ALEV8]

Yep the second one is what I need. ECS has good prices too. Has anyone installed one?

Edited April 18, 2014 by ALEV8

[bjmkelly]

Huge thanks all for this diagnostic aid. The big warning lamp 'Brake Booster Faulty' was ominous and expensive looking but with the help of this thread i fixed it easily and in a satisfying manner.

I found the cracked tube where the spigot enters at the 'JB weld' in the second photo above.

My first approach involved heavy duty metal tape, but the engine heat is intense there and the adhesive turned to mush in a few minutes.

My second approach was even easier to execute. I removed the entire tube from the silver colored booster pump to the spigot - about eight inches in length but with a few fittings - and replaced it with a cut length of vacuum hose from O'Reilly car parts. I used a hose clamp (jubilee clip) at each end, and it all felt rather robust. Total cost was $1.49 for the length of hose plus a few cents for the clamps which were part of a big assortment box i already had (very useful to have around)

The warning light extinguished itself after a minute or two, no programming required.

Thanks especially Voodoocat and Topgun.

[greg schroeder]

I removed my torque brace to replace the bushings.  In doing this I cracked one of the lines to have the warning light come on.  I decided to replace the whole group of vacuum lines.  I bought it from ECS Tuning

 

379307_x600.jpg

 

To replace the group of pre-assembled vacuum tubes I did the following.

 

1. removed plastic cover plates

2. removed three points were the vacuum lines attach and left in position for removal later, two points are clips you can use a pliers to move and reuse.  The third is stuck on there pretty good.  I made a cut on the old part with a razor to remove.

3. removed torque brace

4. Then there is a torque brace mount.  I removed torque brace mounting nut closest to engine

5. The other nut it way inside toward the fender, so i lifted the torque brace mount as if it was a wrench.  you need about a half inch to work the old vacuum line out and new vacuum line in under that part.

6. Put all the vacuum connections on and reassembled.

Edited January 21, 2015 by greg schroeder

[Andrius Kairys]

I know it's an old thread but having a problem with this too..

Mechanic says he checked the hoses aas per my advise and all is good so I bought a pump (2nd hand one) and the problem is still there..

 

Makes me think the hoses need rechecking? IS there anything else which would cause this fault guys?

[Ignited]

just wondering if your mechanic did the step-by-step Greg outlined above? Did he do a smoke test on the vacuum lines?

 

 I would do both of these before buying any more parts.

 

Tim in Ft Worth

[Andrius Kairys]

Makes me think my mechanic might not even know how to do the smoke test.. I'm determined to get this fixed and will probably take the booster pump off myself to see what's hiding there.. There must be a split hose somewhere !!!

[Andrius Kairys]

You're not gonna believe this. I think I've found it !!! it was almost invisible but a quick blow job lol indicated the split might be hiding under this rubber hose.. got that welded, put another hose over it and the fault cleared.. fingers crossed !!! going to contribute to this forum for sure . sorry had few shots of jack daniels to celebrate no lights warning on dashboard after 2 years of trying lol

[Pkcayenne]

HI does anyone know where each end of this hose connects I've been plugging leaks with fuel pipe from auto zone now my pump for the brakes which one of these cables connects to is always running, could it be snapped behind the firewall under the panel which needs to have the windscreen wiper removed 1st 

[lewisweller]

5 hours ago, Pkcayenne said:

HI does anyone know where each end of this hose connects I've been plugging leaks with fuel pipe from auto zone now my pump for the brakes which one of these cables connects to is always running, could it be snapped behind the firewall under the panel which needs to have the windscreen wiper removed 1st 

Bit hard to tell but I believe he is holding pipe 13 which connects to hose 14 in the diagram attached. 

Hose 14 then connects to the pump 19. 

[Pkcayenne]

Hi Lewis I have a pipe going through the firewall under the pump number 19 on the picture. To get to the other side I have to take off the windscreen wiper and the black panel on the passenger side.

[lewisweller]

8 hours ago, Pkcayenne said:

Hi Lewis I have a pipe going through the firewall under the pump number 19 on the picture. To get to the other side I have to take off the windscreen wiper and the black panel on the passenger side.

The pipe 13 is the one that runs behind the firewall to the brake booster. The diagram is not showing its actual length I don't think. I can't find any other diagram of any other pipe so it must be 13. 

Some pictures is always good to share! :-)

 

 

[Pkcayenne]

Hi number 19 the pump is working but a tick tick tick when running any ideas ?

[Pkcayenne]

Can someone check if there vacuum pump ticks ?

[lewisweller]

1 hour ago, Pkcayenne said:

Can someone check if there vacuum pump ticks ?

Pulsing sort of noise yes but should not run all the time which means leaking pipe, connections or the brake booster is leaking internally itself. You get psm failure light as well? 

Looking back through my service history or previous owner Porsche replaced the pipes and brake booster and master cylinder after psm light came on according to the workshop report. 

Have you tried to suck and blow the pipe 19 when you pull the hose off the vacuum pump? Check valve in the line should mean you shouldnt get anything either way with just your mouth. If you can blow or suck air then remove the whole pipe and test it off the car maybe split or maybe check valve is stuck. If no leaks then its the brake booster. 

[Pkcayenne]

Thanks will buy a new hose 1st the booster vacumn pump is constantly running

[ekstroemtj]

I am in the same boat now. The bad thing, i am 1000 km away from home. Why this kind of things need to happen always far from home. I inspected all tubes like explained here. Couldnt find a crack. The brakes are behaving as usual. Until now. I have to drive back 1000 km. What to do? Any idea? Thank you

[Pkcayenne]

Must be a small hole I've been driving mine for months with no problems I'm ordering a new cable this week 

[ekstroemtj]

@PkcayenneThank you for writing. I will check again carefully for splits

[Pkcayenne]

Hi I've patched mine so much it's a 100$ cable I'm ordering it because it's ongoing. 

[ekstroemtj]

Could manage to drive home 1000 km with warning still in the display. I taped some sensitive areas just in case but didnt help. Tomorrow i will see what my OBD tool will tell me

[ekstroemtj]

Check the codes with my iCarsoft.

I found:

 

P1431

P1428

P1429

 

Looks like some kind of electric problem.

I cleared the codes and made a round. No warning on the display anymore. Strange. What could cause this.

 

[ekstroemtj]

The warning came back.

With a bunch of codes. Lots which I never see before. Looks like electric

Problem.

 

 

 

[ekstroemtj]

Whats going on here:

 

 

[lewisweller]

8 hours ago, ekstroemtj said:

Whats going on here:

 

 

Wow! 

Whats you battery voltage like? 

 

Also I would be checking for broken wires of the engine loom which run from the DME to pretty much all the items of the fault code. 

 

Clear the codes and recheck straight away with engine running. If the codes immediately pop back up then wiring is my guess. If the codes come back after a while of driving then very strange low voltage, DME or accumulation of errors. All very strange but as we know with the cayenne even a few corroded wires in the foot well under the carpet can cause a load of warnings, lift up the carpet and see if any wires are damaged or wet, take pictures. 

[ekstroemtj]

@ Lewis , thank you for your info

i will check the battery now and some fuses if there is something wrong