By Dwayne Denny. May 14th 2008.
When the dealers pulled the car up for me to test drive, the first thing I noticed was a sucking noise behind the drivers seat. I told him it sounded like the car had a vacuum leak. He quickly replied these cars sound like that. A few days later, I pulled the left engine cover off and could not find the source. I did find a vacuum leak at the rear of the car, beneath the hood latch assembly. John at “Lamboweb.com” told me that I was correct in assuming it should be capped off. It was left open as a result of someone improperly installing an after market exhaust system (which excluded the need for it). A few days later “rockpool” on Lamborghini-talk.com responded to my post and told me that he had the same problem and it was the result of a broken vacuum “T” located behind the drivers head inside the fender. I sent him a few pictures and he pointed me in the right direction as to how to test for it as well as how to repair it. In the same spirit I would like to share my notes with others so here is the write up on the repair.
Proceed at your own risk, this is for informational propose only. All repairs should be made by qualified mechanics only.
First you will hear the sucking noise. Second you may experience harder or poor brake quality. This is due to the fact that the brakes are vacuum assisted. Take these steps to determine if you have a break in the main vacuum line:
1. Locate the main vacuum tube located on the left side of the engine wrapped in a black mesh.
2. Remove the hose and cap the tube coming from the engine with your thumb, the sucking noise should stop. If it does proceed to step three. If it doesn’t this write-up is not for you.
3. Order the replacement part in advance. Even if you don’t need it you may by the time you move the hoses around. I believe the correct part number is 40611921 Pipe Union. I ordered mine from Lambostuff.com.
4. Next remove the engine side cover using a T-20 torx, T25 torx, and a ½” deep socket.
5. The connection you are looking for is located just above the fuel filter behind the “RESERVOIR ACC.COMPL.”. It is a black box with three hoses connected to it (two black one grey). To remove it you will need to, disconnect the two hoses closest to the rear of the car by squeezing in on the tabs. Next remove the two 13mm bolts and the mounting bracket. Having removed the bracket you will now have room to remove the last hose connection.
6. To remove the black box you will need to shimmy the fuel filter forward a bit (make sure you slide it back when you are done).
7. Once you have the black box out you can locate and repair the broken vacuum “T”. Here is what it will look like:-
The small lower hose is the one that breaks off. This hose supplies vacuum to the brake booster.
8. Install new part, secure with hose clamps and re install all items you removed.
This page was last modified on 03/12/2014
This page was last modified on 09/06/2014