Another Rear Brake Problem.....

Hi Guys,
Here is another Jetta rear brake problem.
I changed the rear calipers, pads, and rotors on my '06 wagon and can not bleed the drivers side. When I open up the bleeder screw absolutely nothing comes out. No fluid, no air, no bubbles. I have done the VCDS ABS Module bleed procedure and the three other calipers bleed just fine with nice clean bubble free fluid coming out. I have opened up all three of the brake line joints from the banjo bolt at the caliper, the flex line to the body and still nothing. Is it possible to have a blockage inside the ABS module? The car has a mk60 module and does not have ESP or ADL and there are no brake trouble codes displayed. Would someone have the port outlet diagrams for the ABS module?
Thanks in advance,
Grunt

Pull the hose off the one that won't bleed and see if any fluid comes out. It could crimped or swollen up on the inside not allowing the fluid to pass through. If no fluid with it off, start tracking the brake line backward for any damage. If fluid flows, then the caliper could be bad.

Grunt, I'm wondering whether you can pull a vacuum on the line to help pull out any potentially lodged debris. If you had a power bleeder that would make it a bit easier.

Try gravity bleeding, if that doesn't work, fill up mc, put some hose on the nipple, insert the hose into a clear bottle with some brake fluid, have a buddy sit in the car, open the bleeder and have him pump the brakes, if you still can't get anything, try cracking the line at the abs, if nothing at the abs, its faulty, if fluid then you have a blocked/damaged soft line at the caliper-did you use pliers to pinch the flex hose?

Thanks for your replies, but as I said I have tried bleeding it and the other three calipers bleed clean just fine. Found a port diagram on line and cracked the line at the ABS Module and blew air back from caliper bleed nipple to the module. No obstruction in the brake line from front to back so...... the blockage must be in the ABS Module itself. Great So now I am going to disconnect the inlet and out lines at the module and blow air in at the rear outlet port to see if it clears what ever is causing the obstruction. Does anyone know if the VCDS would find a fault with a bad solenoid inside the electronic control section of the ABS module? Also does anyone know if the ABS Module spool valves are spring centered? Sure could use a parts diagram for the the ABS Module.
As always, thanks in advance.
Grunt

What happens if you remove the bleeder screw completely? I suspect corrosion inside the bleeder screw. I had to change the right rear caliper after the bleeder screw pulled the threads from the caliper.
I just realized that the OP replaced the caliper; so my comments probably do not apply unless he got some defective, local replacements. I had bad luck with the calipers from Auto Zone.

if there new calipers did u check too take out the almost invisible carriage plug.

if needed i know where an ABS module is. i would have to talk to my buddy and see if he wants to sell it. its from an 02 jetta.

moparvwfrak said:

if needed i know where an ABS module is. i would have to talk to my buddy and see if he wants to sell it. its from an 02 jetta.

Click to expand...

There are 3-4 different ABS modules, need to compare to his, to make sure they are the same.

moparvwfrak said:

if needed i know where an ABS module is. i would have to talk to my buddy and see if he wants to sell it. its from an 02 jetta.

Click to expand...

TEST TEST TEST!!!

Have you removed the bleeder screw completely?

As mentioned before trace the line back and trouble shoot it properly.

Pull the screw and try to see if you get fluid out, if not pull the line from the caliper and see if fluid will come out.
Continue this process until you get to a point that fluid comes out.
The issue il likely the part before that didn't let fluid out.

Thanks but...

Thanks for all your replies but....people please read my post(s).

As I stated twice already I have cracked open all the line joints from the module outlet back and the calipers are new, so no corrosion on the new bleeder and how can you install the flex line banjo bolt with the plastic cap in?
As for using pliers to pinch off a hydraulic line,well that practice would get you fired from any reputable shop.
Thanks for finding a module moparvwfrak but I have already found one close to me.
These are the questions I need answered;
Does anyone know if the VCDS would find a fault with a bad solenoid inside the electronic control section of the ABS module?
Also does anyone know if the ABS Module spool valves are spring centered or pilot operated?
I sure could use a parts diagram for the the ABS Module, anyone?

Sorry if I sound a little pissy but..........
Grunt

On my wife's A3 Jetta I was using my Power Motive Bleeder at 10 psi and nothing came out; I went and pushed down on the brake pedal and some dark nasty **** popped out. It was a Texas car and I bet the brake fluid was original.

I let mine go about 5 years, the fluid from the rears were like 120w oil, never seen that before.
Back to the subject at hand.
The VCDS may or may not find codes for specific components in the ABS. Do you have an error code?
At this point I might disconnect the brake line at the master cylinder, connect a tube looped back into the reservoir and pump the pedal. You should be able to tell if it's pushing pressure. Then clear/clean the line to that wheel, maybe pre-fill it, reconnect and repeat bleeding. Simplify where you can. You'll get it.

Yup, that's the thing, nothing comes out. I'd be happy with some s****y stuff. Here's the thing, all the line joints have been opened and I have blown air back through the lines from back to front, no obstruction. Have opened the outlet port on the module by taking the fitting out pumped the pedal and nothing. Blew air directly into module to try and dislodge anything that might be the cause of the blockage, nope didn't work either. So since there is no fault or error codes I am pretty certain that there is a problem inside the hydraulic portion of the ABS module and not the ECU part of it. Will be taking it apart sometime later today or tomorrow. Will post what I find. Hopefully the hydraulic section of the used module that I have picked up will be interchangeable.

Grunt

Some food for thought;
Gravity bleeding - less than 1psi in the hydraulic system
Vacuum bleeding - not more than 1bar (14.7psi)
Pressure bleeding - from 15psi to 30psi
Old fashioned manual bleeding - greater than 2000psi

When using the Motive bleeder I've read that it's supposed to be no more than about 13 psi (I think - I target 11 psi). I wonder why that is?

Hi Grunt, was there ever a resolution to your issue? I’m have the same issue - no fluid past the ABS unit. I’m thinking I have dirt in the ABS unit and the ports are smaller for the rears making any contamination in the system show up in the rear brakes. Help please.

Grunt has not been back since that thread 1.4 years ago.
If you suspect it's contaminated you might try the VCDS bleed procedure, it uses 2 big bottles fluid. If it's just one wheel you might want to pinch then remove the brake like connect, open the bleeder and see if it's open thru the caliper. Then stick the un-pinched brake line in a container of fluid, hit the brakes to see if you get bubbles. If all that fails disconnect line at the ABS and check if it's open. At this point you will need to do the ABS flush.

Vulcan -Did you find a resolution to this ABS control module not allowing fluid to one of the rear calipers. I am having same issue.

Anybody ever come up with an ABS port diagram? I need to replace the driver side front brake line from the wheel to the ABS unit and I can't trace the line , so I need need to know which line on the ABS pump is for the left front wheel. Thanks