View Full Version : What does that part?

01-05-2011, 09:30 AM
I did a leak test this week end and i found that the cap of this part : 058 133 753B, was off,
So i tried replace it correctly but everytime i was putting 20 lbs it was popping, so i bought epoxy glue to fix it permanatly
So do you think i should replace it?

01-05-2011, 04:00 PM
It is not 2 pieces. It is one piece and there is no "cap". If it has blown apart, it is damaged and must be replaced. Epoxy is an OK solution in the short term, though.

Make sure to get the updated part: 058 133 753D

The new one is reinforced so it doesn't blow apart at that weak point.

01-05-2011, 05:29 PM
Ahh ok so there was a weakness on this part! Alright then thanks for the info
But what is this responsable of ? I remember when the "cap" popped off, my car started to goes wrong and my cel started

01-05-2011, 05:44 PM
Is that the suction jet pump?

01-05-2011, 06:20 PM
Yes, it is called the "suction jet pump". It provides vacuum to the brake booster as well as the PCV valve. It is somewhat mysterious how it works. It uses the small constant flow of the PCV system to amplify the vacuum applied to the brake booster, using the venturi effect. It was originally introduced on automatic only cars, but was later used on all Audi's.

This part has a few weaknesses:
- The most visible is it actually blowing apart, where the brake booster end comes apart under boost. This is due to it's weak plastic construction, heat cycles, the effects of the blow-by gases, as well as running higher than stock boost pressure (or pressure testing at high psi).
- The other weakness is the propensity for the small PCV passage to clog up. This is common because of the oily blow-by gases create deposits on the internal passage, eventually blocking it off. Once this is blocked off, the venturi effect no longer works, so the piece is no longer adding benefit. Additionally, with the PCV system clogged, crankcase pressure can increase, also causing oil leaks, seal problems, contaminated oil, and sludge.

If you understand how the vacuum system works, you can safely eliminate this device, but some vacuum re-routing and fabricating will be necessary. Normally, the best advice is just to replace it with the updated version. I also suggest to check the PCV valve while changing it. With the small hose disconnected, it is pretty easy to check it by sucking and blowing into the hose. It should flow with vacuum and close with pressure.

01-05-2011, 06:55 PM
Wow man! You really know stuff !! Thats crazyy !!
Thanks imma buy. The new version:)

01-05-2011, 08:50 PM
Not so crazy(!?) The vacuum system is not hard to understand, it just takes some study.

01-06-2011, 03:06 PM
Yes maybe but its not everybody in here that study weaknesses of every part in the vacuum line,
Anyway thanks