ABS brake shudder

[Private Pike]

96 C2 993 Cab

Problem only really exist when we reverse the car in on the drive slightly downhill to turn and drive forwards, this where I get ABS drag the brake pedal goes soft and the slight noise ( braking in snow and sliding is how I describe it )

Drive on the roads it happened twice ABS drag first when braking into downhill RHS turn, vehicle hit a pothole and ABS drag pedal soft as above, but this is normal correct ABS doing it's job, not sure but help needed on this please / advice

 

[Alex]

I'd take a meter reading off each ABS sensor and make sure you're getting the correct resistance. Some info here on it:

http://911uk.com/viewtopic.php?t=84338

 

[Private Pike]

Thanks for the link and advice

 

[Pickled Piper]

Are you 100% sure it is ABS related?

My car does something similar when I reverse out of my driveway. I thought it was a power steering problem. I had it checked out and was advised it was just a characteristic of the system, like a vibration when close to full lock.

 

[Gwsinc]

When reversing slowly with near full lock the 'drag' felt is the ackerman effect where one wheel skips a little due to the change in geometry at the extremes of rack movement - this is perfectly normal and felt more when grip is less than optimal, old tyres or wet ground etc.

For the 'ABS drag' issue - if the sensors all check out I'd make sure the brake fluid is properly bled or replaced, air trapped in the ABS system can cause weird things to happen especially when the pressure/temperature rises (i.e. heavy braking).

Keep us posted.