04 Jetta BEW interminent hard brakes and turbo

Tyrel

Veteran Member
Joined
Aug 19, 2011
Location
Peteborough, Ontario
TDI
2004 Jetta TDI PD BEW
hello all, right now i am experiencing intermittent hard brakes and same with turbo. Have read threads that describe the plastic hose from the vacuum pump which i have changed, noticed when removing this plastic pipe the was suction noise when i removed it. took car for drive and thought i had the issue beat, but about 5-7 minutes down the road, same issue again. i had noticed that the aluminum tube coming out of the vacuum pump can turn and is abit wobbly, not sure if it is supposed to be like that or not. When i placed my finger over the end i felt the vacuum present. after returning home i placed a hose from the check valve at the vacuum pump out to a vacuum gauge and it didn't register anything. When i had the check valve out i could blow into one end and nothing come out but blowing on the other end allowed air to pass through so it is working. Since the gauge didn't register anything i am suspecting a intermittent vacuum pump problem not sure if this is even possible.

Any help would be appreciated.

Thanks
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
You can seal up the vacuum outlet line where it wobbles (which is normal to a certain extent -it should move but not be really loose) with JB quick Weld or the like. There is a seal down inside there that can get worn out. You can usually hear the leak if you wiggle the outlet while the engine is idling.

Be darn sure to leave time for whatever sealant you use to completely cure, not just skim over. Your vacuum pump and engine (where the vacuum pump discharges - into the head area of your engine) will not take kindly to a dose of epoxy or RTV.

To check your vacuum pump you need to unhook the small line off the nipple on the side of the large check valve, and you need to block off the large line going to the brake booster as well. Run the engine at idle, and it should produce over 25" of vacuum (28-29 is common.)

If it does this, then your vacuum pump is good.

If you then hook your brake booster back up and vacuum drops then you have a bad brake booster. Since you seem to have an intermittent issue, operate the brakes a few dozen times, checking vacuum after each operation.
 

Tyrel

Veteran Member
Joined
Aug 19, 2011
Location
Peteborough, Ontario
TDI
2004 Jetta TDI PD BEW
Dan, thanks for the reply, i am assuming that if i have a bad brake booster then this would also have an effect on the turbo since motor can't create enough vacuum for both systems. I will check this out today. Thanks
 
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