Right i have bled the fronts on my cossie with a pressure bleeder and rears using the pump

When i fitted a big brake kit i also changed the fuild for dot 5.1

Problem i have is the brakes pulse when coming to a slow stop

Abs light goes out and stays off while driving

Any ideas could air in the valve block cause this??

Ta

Paul

 

My brakes did this on an old rover i had, they would pulse just before coming to a stop. Turned out one of the abs sensors was playing up. Take out the fuses for the abs and give it a try just to be sure!

 

Ive had similar probs with alot of vw/audi/skoda's. Its normally an abs sensor fault itself or the gapping of the sensor to the pickup or a dirty pickup.

 

I have had all sensors out and cleaned checked gap etc

BUT this only started once i fitted the new brakes and changed fluid

Both abs sensors on the front have been swapped but no change

The only thing is that i have grease on the front pick up ring but that was the same as before

Paul

 

up

 

As mentioned this will be a wheel sensor and is a common problem with Cosworths, as you said you have already cleaned i'm guessing it's a faulty sensor, do as mentioned either remove fuse or unplug abs module. It does it when you moving in slow traffic as well and brake I would suspect.

Although having said this if it worked ok before you fitted big brake kit may this be the cause?

Kind regards,

Martin.

 

Had this problem on my saph after i fitted big brakes, ened up fitting a switch to disable the abs for normal driving so it passed the MOT ok, haven't switched it back on since.

 

Which wire do you put the switch in to disable it?

Thanks

 

From memory there's 4 wires that go into the level sensor on the screwcap at the top of the reservoir, you just wire it in there, i'd have to check TBH mate, i searched on here and got the info then went and did it, worked a treat. Also, mine is a late spec. saph 4x4 so it might be a different wire you need to splice into!

 

don't disable it fix it
measure the output of the wheel sensors at the abs ecu at 15mph all should read around the same you will find one is reading low
all you need is a volt meter that reads AC

 

Tony:

Why do quite a few people experience the same issue when they fit big brake kits? Is it something to do with the bigger more powerful brakes amplifying a problem that was already there (low voltage signal as u state)? I know Rainbird had that switch on his car as he said often cossies pulse at low speeds when coming to a stop - once BBK is fitted? I recall PON saying something similar.

If you have an even better piece of kit you can watch the output on a graph and dodgy abs sensors are really obvious (appreciate most people don't have a scope like that).

Cheers
RW

 

alot of the problems are with the rear and by changing the discs and calipers it's as simple as some crap you have disturbed is now in the sensor rotor
clean the rotor and the loose debris and the problem is fixed
The problem with the cars now is that the system and all it's components are 20 years old and have far exceeded their service life so they all want replacing anyway

 

im glad you said that as i have a problem with my mg zs, i press the pedal and the pump makes one hell of a noise did yours do this also when i touch the pedal the pump is working hard like ive slammed the brakes on hard