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Volkswagen Rabbit, GTI: 2006 and later (A5G) correct bleed sequence?


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Last Post: Dec 26, 2010 1:50 PM Last Post By: clutchnshift
dporter

Posts: 2
Registered: 08/28/07
correct bleed sequence?
Posted: Sep 19, 2007 7:50 PM
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I have the A5G CD-ROM and the documented brake bleed sequence is contradictory in several sections of the manual. What is the correct bleed sequence for this car, and will the manual get updated? Thanks.
autobahn

Posts: 516
Registered: 08/17/05
Re: correct bleed sequence?
Posted: Sep 19, 2007 10:06 PM   in response to: dporter in response to: dporter
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I do not know what the manual says, but you typically start with the corner furthest away from the master cylinder. Master cylinder first (if applicable) than right rear, left rear, right front left front.
FKH161

Posts: 7,661
Registered: 12/29/05
Re: correct bleed sequence?
Posted: Sep 19, 2007 10:34 PM   in response to: autobahn in response to: autobahn
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--------
Volkswagen > GTI, Rabbit > 2006-2007

Brake System

47 - Brakes - Hydraulic components Bleeding braking system

Description covers bleeding of brake system using the
brake filler bleeder unit VAS 5234.

Note:
Bleeding the braking system on vehicles with ABS is
carried out as for vehicles with conventional braking
systems.

Only use new brake fluid conforming to US-Norm FMVSS 116
DOT 4.
--------------

Make your own VAS 5234:

http://faculty.ccp.edu/faculty/dreed/Campingart/jettatech/bleeder/index.htm

What are the contradictions?

If you need to bleed the ABS valves & pump... there is
slightly more to it.

dporter

Posts: 2
Registered: 08/28/07
Re: correct bleed sequence?
Posted: Sep 20, 2007 2:31 AM   in response to: autobahn in response to: autobahn
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I do not know what the manual says, but you typically
start with the corner furthest away from the master
cylinder. Master cylinder first (if applicable) than
right rear, left rear, right front left front.

This is what I'm inclined to do, but the inconsistencies in the manual concern me. Here is what it says in various sections:

Volkswagen > GTI, Rabbit > 2006-2007 Brake System 47 - Bleeding braking system

LF RF LR RR

Volkswagen > GTI, Rabbit > 2006-2007 01 - Description of work (part 1 of 2) Brake and clutch systems, changing fluid

RR LF RF LF (in directions)
LF RF LR RR (in table)

There may be other places where this is mentioned too, but the digital manual is a pain to nagivate.

autobahn

Posts: 516
Registered: 08/17/05
Re: correct bleed sequence?
Posted: Sep 20, 2007 5:15 PM   in response to: dporter in response to: dporter
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As long as you have a firm brake pedal where the stroke does not decrease after a couple a strokes you should have done the job.

I would start doing it the conventional way and see what happens. You can always go back and try a different sequence.
maestro1

Posts: 1
Registered: 06/24/08
Re: correct bleed sequence?
Posted: Jun 30, 2010 6:09 PM   in response to: dporter in response to: dporter
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I have noticed the same thing on my manual and wanted to ask the same question...I'm glad i'm not the only one that noticed it. Perhaps as this is brought up by people readers, they should revise the material and update the customers in certain inaccurate/confusing publications.
clutchnshift

Posts: 1
Registered: 10/03/09
Re: correct bleed sequence?
Posted: Dec 26, 2010 1:50 PM   in response to: dporter in response to: dporter
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Late in replying, but valid nonetheless. I know the Jetta is a whole different car, but the comment by AUTOBAHN is contradicting my manual. My manual is Volkswagen Jetta Service Manual 2005-2010 Models. On page 47-3 (Brakes-Hydraulic), Bleeding Brakes states the following (verbatim):

====================================================
"The design of the ABS hydraulic unit requires that brakes be bleed in
the following (non-traditional) order:

  • left front brake
  • right front brake
  • left rear brake
  • right rear brake

If this order is not followed, proper bleeding cannot be ensured."
====================================================

By looking at an exploded view of the ABS hydraulic components on page 45-5 (Antilock Brakes ABS), I found the ABS hydraulic unit to look like a Electro-Hydraulic Servo Valve (Electrically Operated-Hydraulically Controlled). These EHSV's are responsible for porting hydraulic fluid to actuators, or in the case of ABS to the individual Brake Calipers which actuate the pistons onto the pads. Anyway, I used to repair and test Brake Servovalves for the A320 & B747 aircraft. These Brake Servovalves are responsible for restoring or removing hydraulic system pressure as necessary to the brake systems, normal & alternate, as necessary so that wheel skid is prevented while maintaining sufficient braking pressure for optimal stopping power. It is the equivalent of ABS on a vehicle, but on aircraft it's called "Anti-Skid". My point is that when I would test these, BLEEDING PROCEDURE is very important, the system/component must be free from air before a full scale test is performed (or normal use). Trying to operate a Servo Valve with air in it will not only make it operate in unwarranted ways, but it will also run an exponential risk of damage to the Servo Valve itself, it is after all a precision compoenent. Bottom line, procedure is important and the idea of bleeding the caliper furthest from the master brake cylinder and working your way towards it does not coincide with what is in my 2005-2010 VW Jetta Service Manual quoted above, which is actually the exact opposite in direction. With all that said, I can see why using the diagnostic scan tool, VAS 5051, is also important.


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