406 ABS faults

[chiefclancy]

hi folks i have a 2000 406HDi estate with an abs fault,the abs kicks in nearly all the time,ive had it scanned(several times mate with a scanner)no faults ever found,all the abs rings have been checked,its had a replacement pump fitted,just had new discs and pads fitted(front),fault was there before the D&Ps were fitted,my mechanic and i are running out of ideas of what it could be thats causing the fault,any ideas would be greatly appreciated.

[steve_earwig]

No, you covered just about everything

Pump? What pump?
Reluctors - hairline cracks shouldn't have any effect because people cut them in half and glue them on. Must be free from heavy corrosion.
I can't imagine the air gaps changing.

Does the car have ESP?

[Ares]

hmm interesting problem.
we need to go here with logic.
so abs is going on constantly.
is there any pattern,like it goes on while driving up hill or something,can it be some wire is damaged so it goes wild from time to time?

[lozz]

It couid be a Faulty Abs sensor.
even tho they look good and throw up no fault codes;

New sensors can still be faulty too,

there is a way of checking them with a Multimeter,

have you Cleaned and checked all round the Abs rings.
sometimes they can have cracks so fine its hard to see them.

[chiefclancy]

it only does it when braking,not just at any time,you question the "pump"as in the ABS unit under the bonnet.reading past posts are the rear "rings"only on the wheel bearing kits.My mechanic is fed up of looking for faults but will get him to try and check sensors with multi meter,thanks in advance

[puggy]

Had exactly the same problem on my 2000 hdi est , both front abs
rings , started by doing it occasionally and when looked at could see nothing
then all the time at this stage one of the rings had opened slightly.

[mattyg]

I had this fault i cleaned up the rings with a small wire brush and it hasnt played up since and that was months ago !Fingers crossed. might be worth another go its a cheap fix and you have nothing to lose,

Matt