Central Locking working pressure

Thread Tools
 
Search this Thread
 
Old Dec 9, 2011 | 10:19 AM
  #1  
Bruch's Avatar
Thread Starter
AudiWorld Member
 
Joined: Sep 2002
Posts: 301
Likes: 0
From: Irwin, PA
Default Central Locking working pressure

This weekend I hope to find the leak in my centrla locking system on a '95 90. The PO had aftermarket speakers installed in the rear doors so thats the first place I'm looking.

My question is, does anyone know the working pressure of the system? I thought I might hook up an air line at 3 psi or so to help find the leak. Pull the line off the pump in the trunk and hook up my air line there.

Any thoughts?
Reply
Old Dec 9, 2011 | 12:40 PM
  #2  
hubturn's Avatar
AudiWorld Member
 
Joined: Mar 2007
Posts: 541
Likes: 0
From: Charlotte, NC
Default

While the logic makes sense that you'll hear the leak, I'd be hesitant to put pressure on something that normally has a vacuum on it, particularly something with 17 years of age on it. If you blew out a rubber bellows switch, you'd hate yourself because it would happen to be the most expensive switch in the system and it would only be available from the dealer. (Audi's Law) A note in Bentleys says that if the pump operates linger than 5 seconds, you have a leak, and that if the pump runs for longer than 30 seconds, the central locking control module must switch the pump off. I think I would start with a Mity Vac to get an idea if it is a slow leak or a big leak that might represent a disconnected line, considering that the Idiot PO was in there tinkering around. (I Hope the PO is not related to you.)
Reply
Old Dec 12, 2011 | 08:52 AM
  #3  
Bruch's Avatar
Thread Starter
AudiWorld Member
 
Joined: Sep 2002
Posts: 301
Likes: 0
From: Irwin, PA
Default

Resolution...

Accessing the system at the rubber Y next to the pump, the Mity Vac acted like I had no hose hooked up at all. Which is how the system behaved; the trunk would lock, but the pump would time-out before the door locks moved either way. I measured the output of the pump when it was in push(blow)mode, and got approx 1-2psi. So I hooked up my little regulator that I use for pressure bleeding the brakes/clutch and put 1.5psi into the system.

I appreciate the risk, but when you have a parts car, you get brave with this sort of activity!

I heard the hissing near the pass door, pulled the panel and still couldn't find it. Turns out, there is a rubber Y under the pass side carpet that had come apart. I pushed the plastic tube back into the Y, and everything works as expected. I put a little glue on the tube for luck.

Bruch
Reply
Old Dec 12, 2011 | 12:05 PM
  #4  
hubturn's Avatar
AudiWorld Member
 
Joined: Mar 2007
Posts: 541
Likes: 0
From: Charlotte, NC
Default

Excellent diagnosis in spite of bad advice. I don't know why I thought it was a vacuum system vice a pressure system. Old GM and Ford knowledge bleeding into my aged brain, I guess.
Reply
Old Dec 12, 2011 | 05:14 PM
  #5  
Luxus Panzer's Avatar
AudiWorld Super User
20 Year Member
 
Joined: Feb 2004
Posts: 7,677
Likes: 0
From: Canada (NCR)
Default

Originally Posted by Bruch
Resolution...

Accessing the system at the rubber Y next to the pump, the Mity Vac acted like I had no hose hooked up at all. Which is how the system behaved; the trunk would lock, but the pump would time-out before the door locks moved either way. I measured the output of the pump when it was in push(blow)mode, and got approx 1-2psi. So I hooked up my little regulator that I use for pressure bleeding the brakes/clutch and put 1.5psi into the system.

I appreciate the risk, but when you have a parts car, you get brave with this sort of activity!

I heard the hissing near the pass door, pulled the panel and still couldn't find it. Turns out, there is a rubber Y under the pass side carpet that had come apart. I pushed the plastic tube back into the Y, and everything works as expected. I put a little glue on the tube for luck.

Bruch
You got any pics of the location of this "Y" junction?

The wifes 90 has a problem with both the drivers side doors not locking with the vac system
Reply
Old Dec 14, 2011 | 08:53 AM
  #6  
Bruch's Avatar
Thread Starter
AudiWorld Member
 
Joined: Sep 2002
Posts: 301
Likes: 0
From: Irwin, PA
Default No need pictures

Originally Posted by Luxus Panzer
You got any pics of the location of this "Y" junction?
Pull up the plastic door sill cover, after removing the front kick panel. (the panel in front of the door opening, whatever it's called)
Lift while wiggling to release it from metal spring clips.

The Y connector is under the carpet about 3 inches from the outer floor mat anchor post. You'll see vaious wires and tubes in a track under there. The Y connects the tube from under the back seat with the 2 doors on the passenger side. Be careful not to slice your arm open on theose metal clips.

BTW, the door locks open with pressure from the pump, and they lock using vaccuum from the same pump.

Tell us what you find.
Reply
Old Dec 15, 2011 | 04:32 PM
  #7  
Audicted's Avatar
AudiWorld Super User
 
Joined: May 2000
Posts: 3,105
Likes: 0
Default

This is an awesome post.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
apostle411
A4 (B6 Platform) Discussion
7
Feb 23, 2010 09:42 PM
007TT
TT (Mk1) Discussion
4
Apr 24, 2006 12:28 PM
Chard
A4 (B5 Platform) Discussion
2
Sep 13, 2004 07:12 PM
Jay 4R
A4 (B5 Platform) Discussion
4
Mar 1, 2003 04:21 PM
scotTT
TT (Mk1) Discussion
1
Jul 7, 2002 12:48 PM




All times are GMT -8. The time now is 08:57 PM.

story-0
New Audi A6 Allroad Is The Market's Coolest Wagon: 9 Things to Know

Slideshow: Audi's latest A6 Allroad gets RS-style fenders, real off-road hardware, and enough personality to stand out in a market obsessed with crossovers.

By Pouria Savadkouei | 2026-06-16 17:31:52


VIEW MORE
story-1
10 Strangest Audi Designs That Actually Made Production

Slideshow: 10 strangest Audi designs that actually made production

By Joe Kucinski | 2026-06-10 16:32:29


VIEW MORE
story-2
2027 Audi Q7 and SQ7: Audi Upgraded EVERYTHING!

Slideshow: Everything you need to know about the 2027 Audi Q7 and SQ7

By Michael S. Palmer | 2026-06-09 06:02:56


VIEW MORE
story-3
Audi Unveils Absurdly Cool New Supercar: 10 Things You Need to Know!

Slideshow: Limited to just 499 units, the 987-horsepower halo car signals a new chapter for Audi performance.

By Verdad Gallardo | 2026-06-04 17:37:15


VIEW MORE
story-4
The Highs & Lows of Every Audi C-Class Generation

Slideshow: The highs and lows of every Audi C-Class generation.

By Joe Kucinski | 2026-05-27 16:05:50


VIEW MORE
story-5
Top 10 Most Expensive Audis Ever Sold on Bring-A-Trailer

People were more than happy to shell out big bucks for these cars.

By Brett Foote | 2026-05-27 15:32:23


VIEW MORE
story-6
10 Audi Features & Options We Miss the Most!

Slideshow: 10 Audi features and options we miss the most.

By Joe Kucinski | 2026-05-12 19:33:47


VIEW MORE
story-7
Audi Recreates Crazy-Looking Speed Record Breaker From 1935

Slideshow: Audi has recreated one of the wildest machines of the pre-war speed-record era, reviving a streamlined V16 racer that originally exceeded 200 mph in 1935.

By Verdad Gallardo | 2026-05-11 09:49:34


VIEW MORE
story-8
Coachbuilder Recreates the 1995 Audi TTS Concept

Slideshow: A Dutch coachbuilder has reimagined the original Audi TT by finishing what the 1995 concept only hinted at.

By Verdad Gallardo | 2026-05-05 15:17:58


VIEW MORE
story-9
Every Audi V10 Car Ranked!

Slideshow: Ranking every Audi V10 road car

By Joe Kucinski | 2026-04-29 16:11:56


VIEW MORE