Cracked brake booster line cause boost leaks??

[Nikogti]

Would a cracked brake booster line cause boost leaks?

The car is tuned for 25psi stage 2 but I'm only getting 18psi and holds it but then sometimes it drops down to 16psi then 15psi. It feels like stage 1 but the tuner tested it on his own car and he hit 25psi and then held 23psi. I haven't seen mine gone past 18psi.

Thanks for any help

[sambb]

The brake booster line has a one way valve in it. If you follow its line from the plenum connection towards the brake booster you will find it. It will allow the lenum to draw vaccum onto the booster diaphragm but not apply boost to it. If you have a leak in the booster line pre- 1 way valve then yes you will have both a vacuum and a boost leak. If the leak is post 1 way valve then you will only have a vacuum leak.

[Nikogti]

Thanks sam for always helping 👍 but I give up mate I'm making a boost leak pressure test with plumbers cap and tyre valve. Plus ordered a smoke machine from ebay. Hopefully i sort the car out and find the boost leak

[sambb]

Probably worth checking the adjustment on the wastegate actuator rod. Check that it has 3mm of preload on the flapper - lots of you tube vids on setting wastegate preload. That'll rule out a loose rod/insufficient preload. Then after that, unplug the N75 boost control solenoid and watch your boost gauge. It should hit and stay at 6psi. If not then your wastegate actuator could be the culprit. good luck with the smoke tester.

[Nikogti]

Thanks mate I'll look into it today but it's just so weird becuase my stage 1 from underground performance runs fine but as soon as I plug my stage 2 ecu and load it up in 5th gear I hear this weird metal clapping noise coming from the drivers side or it could be a boost leak but I can't find it.. I've tighten every clamp and upgraded all clamps..
The smoke machine won't arrive for another 7days it's coming from the states but I'll give the above a try after work today.
Thanks for all your help Sam

[h100vw]

Thanks mate I'll look into it today but it's just so weird becuase my stage 1 from underground performance runs fine but as soon as I plug my stage 2 ecu and load it up in 5th gear I hear this weird metal clapping noise coming from the drivers side or it could be a boost leak but I can't find it.. I've tighten every clamp and upgraded all clamps..
The smoke machine won't arrive for another 7days it's coming from the states but I'll give the above a try after work today.
Thanks for all your help Sam

Whats the stage 2 tune?

[Nikogti]

The tune is from the states 06atechnik i got stage 2.. No lift shift.. pops and bangs & omfg its so loud like gun shots honestly scary.. And 2 step at 3500rpm all deletes cat n75 secondary pump etc. Tuned for 25psi peak and 20+ holding..
Its just weird cause if i put my stage 1 ecu from UGP i fry 1st and 2nd gear with traction control on but with my stage 2 ecu its like the power comes on and then dies out above 5k .

I just unpluged the n75 plug and it hit 6psi and then plugged it back in and i hit 19psi for the first time.

[Nikogti]

Thanks Sam just hit 22psi LOL all i did was unplug the n75 switch and plugged it back in so happy now

[h100vw]

Have you logged this stage 2 ECU? 25psi is loads.

[Nikogti]

I will get logs from my mechanic next week he can plug his scanner in for live logging but found this tuner from a guy on yt he has about 400.000km on his gti with all stock internals running the same tune hitting 20+ psi on the daily and so far he's done 15.000km and other people safely doing 80.000km so far on this tune with no dramas or issues. And for the price I couldn't complain even that it was a xmas gift from my wife plus all the mods done to get it to stage 2.

[h100vw]

I will get logs from my mechanic next week he can plug his scanner in for live logging but found this tuner from a guy on yt he has about 400.000km on his gti with all stock internals running the same tune hitting 20+ psi on the daily and so far he's done 15.000km and other people safely doing 80.000km so far on this tune with no dramas or issues. And for the price I couldn't complain even that it was a xmas gift from my wife plus all the mods done to get it to stage 2.

Doesnt mean that it is running correctly on yours though. Please keep off the gas until it's been logged and checked.

[Nikogti]

I don't think it is running well now cause I'm reading -5 now on vaccum and it was -20 this morning

[h100vw]

I don't think it is running well now cause I'm reading -5 now on vaccum and it was -20 this morning

definitely a leak there then

[sambb]

At idle - then that's got to be something coming off the plenum eg brake booster, PCV line, SAI lines, N249 diverter valve reservoir lines, the boost gauge vacuum line itself, the silly suction vacuum pump Y piece that goes into the brake line has a smaller line running to the TIP with a one way valve, injector cups can crack and injector O-rings perish. Could be torn hose, usually at the connection point, a 1 way valve stuck open, PCV hard plastic fitting into the block is cracked, dipstick tube cracked. Spray WD40 at all the connection points that lead to the plenum with the car idling/vacuuming. If something is open to atmosphere it'll suck the WD40 and flare the revs a bit.

[Nikogti]

Thanks guys I will look into it tomorrow and try the wd40 trick but on start up it's -10 and after a drive it sits at -2 to -5 on idle