ABS
 

hi just looking over car for MOT tomorrow, when ignition on fuel pump runs pressures up then off, but there is a loud buzzing coming from the servo area, its a 2wd sappire, buzzes for about a minute, then after about 10 secs starts again, even when engine started the same thing??? does this mean the ABS system is trying to pressurise over and over,possible leak? but is it air or fluid leak im looking for?
or is it nout to do with abs?
any ideas
also noticed an oil drip at the back of the gearbox, on the bottom plate, is this a seal gone or what should i be looking for here, the car has been stored for 3 years, then i bought it,been changing fan switch thermostat and fixing coolant leaks here and there, also changed oil and filter, just took it a run yesterday and noticed the buzz and oil leak also think discs are warped as the steering wheel shakes on braking,
john

Mine has stated to get a bit shakey under braking and it's the track rod end's that need changing, could also be the bushes in the TCA's which are common on a sierra or the ball joint on the TCA, worth checking these before getting new discs.

Buzzin from the abs pump could mean air in the system or a leak, i'm guessing there is plenty fluid? Apart from that i wouldn't know where to start.

The buzzing is NORMAL, as the cossie doesn't have a normal vacuum assisted servo, it generates fluid pressure to assist the brake function, the noise is the pump running.
It should normally run for around 20-25 seconds first turn of the key in the morning, coming on after just starting is normal, but it will tend only to do this when cold, once up to pressure you will rarely if ever hear it.
It just needs a little use to settle down that's all.
If the pedal is ok , then you have no air.
Any leaks will/should be spotted at mot, the shake sounds std for cars stored for this long, the discs rust, and will do this till cleaned up by the pad, so give the brakes some work to do, sometimes if bad enough they won't clean up so new disc time.
Track rod ends won't cause this unless totally shagged, but you'd feel that in other ways.
These things though should also be found in a any decent mot.
tabetha