ABS problem(BOSCH system) on my R19 16v

[justast]

The problem started just recently. ABS is kicking when i go on slow speeds up to 10mph. In the morning when i do few stops and build up speed everything seems all right. But problem still stays when moving slowly in trafic. Can it be ABS rings? What do you think?

 

[Neal R19]

what do you mean kicking in? randomly applying the brakes? or just when you do actually brake?

In any case, I'd take a wire brush to the rings and sensors and check their resistances at their little yellow connectors. Should be about 1000 ohms iirc, but I guess you're just looking for consistency really.

 

[justast]

I meant that when I brake ABS starts to work as if the wheels are locking. This is hapening all the time when car is left for few hours. Soon I will do a lot of work on the brakes, but I just dont want to go back to them at all when i'm finished. So I need to find out what is actualy wrong.

 

[Chris H]

its a ring issue most likely.

Common fault when the rings crack is under 10 mph the abs kicking in.

At higher speeds the signal clears up so the module doesn't see a fault. Slow the wheels down and a sporadic irregularity will cause ABS engagement.

 

[justast]

The problem is still progresing and has new symptoms. If I start the car in the morning and apply brakes few times before starting moving, ABS turns off of some sort of fault. Could be electric or electronic. Turning off and on the ignition eliminates ABS from working incorectly fo a while, but later its the same as decribed in the post above. Is there a posibility to diagnose ABS with something more than a multimeter? Is it worth to to diagnostics at all? I will go throught sensors to mesure resistance, but i fear that the problem is deeper than just sensor...

 

[Neal R19]

Well replace the whole unit if it turns out not to be a sensor/ring issue.

It's not too hard with Bosch ABS as it's all contained within the single lump.

Same system was also used in various vauxhalls of the same vintage ie cavalier/calibra for sure

 

[hooverphonique]

yeah.. and by the looks of it, some citroen zx's also had that same bosch unit..

 

[justast]

Managed to mesure resistance on front sensors. And as Neal mentioned, resistance on one 1050 ohms butfor another it's tiping over 200k, witch is I believe means sensor is dead. So here we go again. Has some one got one. It's right hand side, but does it really makes difference? It does on rear ones, not sure though about front...

 

[hooverphonique]

200k means dead, yes.. it must be around 1000 ohms or it won't work..