# No ABS and soft brake pedal mkiv Jetta



## opelgt21 (Feb 21, 2009)

I have had no ABS (no cel or ABS light) and a soft brake pedal for a year now and just replaced my master cylinder and front calipers. I have power bleed the system and the system is about the same to a little worse. Based on pad wear, I don't think the front circuit is working.

I took it to a vw dealer and stumped the master mechanic who suggested I replace the booster, which I declined. After picking up my car I pulled the booster vacuum line and test drove the car, other than being harder to push the brakes where the same. I then pulled the ABS fuse and other than not having ABS, the brakes where good. I put the fuse back in and now the CEL and ABS lights are on and the brakes are ok (pedal a little soft).

I think I either have air in the ABS (dealer says no) or need a new ABS modulator/ecu. I need to talk with the mechanic to see if they definitly activated the ABS prior to bleeding. Does anyone have any thoughts or experience replacing the ABS unit?


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## Elwood (Aug 10, 2001)

I'd keep working on getting it properly bled. If there is air in the ABS pump, you need to bleed the brakes, cycle the pump, and bleed it again. If you have a Bentley, look up the procedure. You may need to pump the pedal while bleeding with a pressure bleeder (you do with a MKV).


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## tomjv (Jun 15, 2001)

*brakes*

I have the same/similar issue. Did you ever solve it?
TomJV


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## opelgt21 (Feb 21, 2009)

I had air in my abs valve body. 

I fixed it by buying a vag com and running the brake bleeding procedure in the Bently manual that cycles the abs pump. I used a motive power bleeder and bleed the system twice. The abs pump really drains the battery, so I would recommend charging the battery in between bleeds.


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## clarkma5 (Mar 2, 2002)

Yeap! If the pedal is soft enough that you can't generate the pedal pressure, the ABS won't activate. Simple as that. Sorry you went to all the trouble replacing components. I think vortexers have led many astray by downplaying the importance of cycling the ABS pump during bleeding...I've heard often how it's "only necessary in extreme cases, like a dry system". In my experience, it helps in every brake bleed, and I would recommend it being part of your standard operating procedure when bleeding brakes.


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