EGR and vacuum questions - TDi 130

[TeKnodriver]

Hi all, hope you could give some input on the below.

having recently bought this B6 TDi 130 AVF I was considering EGR removal.
had given oil + filter and fuel filter change but torque and low end pick-up still were lower than anticipated.

so, tested deactivating the EGR by removing and plugging the hoses.
First just the ASV connection on the side -
engine seemed same as before , but braking feel and power were 20 to 30% improved!
(i thought the fluid needed changing but feels strong now)
Next the EGR saucer on top -
low end pickup and torque much improved more like I'd expect from the engine

Questions -
if blanking the ASV has improved braking, would this point to a vacuum loss in that unit?
similarly, could there be a exhaust pressure leak through the EGR reducing the boost ability?

think that i'll remove the unit as i have an EGR delete pipe that i never fitted to previous tdi
but hope to understand how this affected the brakes in case there's potentially an issue elsewwhere

 

[Gazwould]

Poor brakes and inconsistent low rpm boost points to lose vac line on tandem pump .

 

[TeKnodriver]

Thanks Gaz -

I've been paying more attention to braking during last few drives, some moments the braking assistance is low ( harder pedal, reduced braking ability)
noted one part number for hose from tandem pump to bulkhead grommet: 8E0 611 931 CD (appears discontinued)
is the check valve in here or the other side of the bulkhead?

Also noted from other TDi forums that the nipple on tandem pump can leak - mine has a definite wiggle to it so may try the sealing recommended here:
https://forums.tdiclub.com/index.php?threads/turbo-underboost-and-stiff-brake-pedal-thoughts.490188/

anyone tried this?

 

[Gazwould]

Mine was lose and experienced inconsistent low rpm boosting and poor brakes so sealed mine with Sikaflex EBT+ .

 

[TeKnodriver]

Got some SBT+ yesterday and applied to nipple edge.
Cured now and the low rpm boost pick up has improved, braking assistance also better
Much smoother to drive in traffic/around town
Thanks for the tip Gaz, hope the seal lasts ok in the heat

 

[Jacko1]

Mine was lose and experienced inconsistent low rpm boosting and poor brakes so sealed mine with Sikaflex EBT+ .

I sealed mine up but in the end it kept failing, I got ****** off and got a modified tandem pump second hand off ebay from a 2009 A3 and fitted it - they have a modified fitting design that wont come loose.

 

[Venomuk]

Interesting read, Drive wise mine feels nice and smooth with good pull at low end. However, I have always thought my brakes felt very wooden almost. brake pedal is quite hard and not a lot happens unless you stand on them at times giving that "wooden" feel that they are simply glazed and little friction (I have changed the pads)

I will look into this further and see what I can find on mine.