Club Touareg Forum banner
Cancel
Create thread New Garage Forums

Fun with Vacuum. Brake issue? V10

Jump to Latest
3.1K views 6 replies 4 participants last post by  italmind  
I
#1 · (Edited)
(My apologies if this supposed to be in the brake forum)

04 V10 150k

Noticed oil leak approximately under passenger side. After some minor exploration, I'm pretty sure its the tandem pump.
I've been driving it like this for about 700 miles. I have recently developed an occasional "soft" brake pedal.
Treg stops fine, While sitting at a light, pedal sinks to floor, and treg will start moving if I dont pump the pedal one time.
Seems like a master cylinder issue, but no fluid loss or change seems to rule that out. If I recall correctly it shouldn't be a booster issue as the pedal isn't hard or lacking in assistance.
I have not checked vacuum lines yet, but it seems safe to assume this is related to the tandem pump leak. Anyone disagree?
Brembo/Pads and rotors have less than 10k on them. Brake fluid level is good ,fluid is clean. Level has not changed since I first noticed the issue maybe 300 miles ago......

I have the new seal for the tandem pump, which I will be changing this week.
I am going to start troubleshooting this tomorrow.
Thought I'd check in with you guys JIC I am missing something
Also no codes when I scan modules

Thanks:)
 
Discussion starter · #5 ·
Thank you all for the replies.
Visual inspection of vacuum lines. Nothing obvious. I will pick up a nice fat cigar later to do a smoke test : )
Tried the master cylinder test as described above. Pedal feels completely normal at idle. Firm and powerful. It will not go to the floor.
I'll report back after I repair the Vacuum pump.
 
Discussion starter · #7 ·
So, just to close this out......
Oil leak ended up being the sensor adjacent to the tandem pump..... replaced o ring. Also rehabbed tandem pump while I was in there.
Brake issue WAS master cylinder. Replaced and bled system. Fixed.
NO vacuum leaks.
Interesting side note. The master cylinder test described above by Togwotee did not work on the master cylinder I replaced. With "egg" like psi on the pedal it would not go to the floor. Out of curiosity I tried the test on the replacement master cylinder. With "egg" like psi the pedal DOES go to the floor. Not sure what to make of that but thought it might be relevant to the thread.

Thanks for the replies!
 
Club Touareg Forum
posts
786K
members
106K
Since
2003
Club Touareg Forum is a forum community dedicated to Volkswagen Touareg owners and enthusiasts. Come join the discussion about VW Touareg Sport Utility Vehicles and more!
Full Forum Listing
Explore Our Forums
General Maintenance & Repair Australia & New Zealand Brakes, Steering, Suspension, Wheels and Tires Mobile Electronics and In Car Entertainment General Touareg Discussions