Hello can anyone assist me in diagnosing possible causes and hopeful solution for a brake vacuum leak on the XUD9TE engine with ATE servo, EGR electro valve? and a replacement cam driven vacuum pump. (previous owner replaced pump in a effort to solve brake issues)
Symptoms are:
Initial vacuum ok and brake operation fine from start-up, vacuum assistance diminishes with three to four applications of the brake pedal to hard pedal and no assistance. Some servo assistance returns after a couple of minutes if left alone?
If the brake pedal is pumped with engine running until hard and then held, brake pedal will sink a small amount over 30 seconds and some assistance returns for one or two applications?
One brake disc is warped, this can physically be felt in the pedal with the pedal oscillating up and down with the warp of the disc?
What I've tested for and checked:
Visual inspection of visible pipes, no nicks or holes.
Vacuum pump inlet providing constant vacuum with engine running.
What I'm having difficulty with:
Servo check / non return valve inaccessible ( reservoir obscuring valve and short braided pipe )
Are the symptoms listed indicative of a failed servo, check valve or another problem?
Can anyone assist?
thanks
Matt
1997 Xsara 1.9 TD Brake Vacuum leak symptoms.
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