Spow

Gents,
Assisted braking has stopped working. This happened to last year & the solution at that time was to replace the Brake Booster Servo. Just fitted a replacement servo which has had no effect. Just checked the warning lights & Differential warning light is + Brake Pressure / Brake Fluid Warning light are on. So checked fluid level & it is low approx 1/3 full but not below any of the fluid outlets. Is this enough to cause an issue? I will get it topped up in the morning anyhow.

Another noticeable symptom is that when turning on the ignition I cant hear the usual noises from what I presume is the hydraulic system. This was also a symptom when the relay failed last year thus leading to the relay diagnosis.

Lastly, it is still driveable just need to exert more pressure on the brake pedal.

As always any advise appreciated.

Cheers
Steve

Spow

Gents,
Topped up the brake fluid started the car up pumped the pedal & found that brake fluid was leaking/pouring out from the hydraulic pressure switch located on top of the hydraulic pump. My guess is that a seal has gone. Can this be repaired or will a new pump be required.

Comments appreciated.

Thanks
Steve

D_Schultz

If you're really REALLY lucky, it might just be the o-ring that has failed. Worth a try replacing that to see if it solves your problem. If the internal seal of the pressure switch has failed - it gets a bit more expensive (mine was something like $150? a while back). Hopefully your pump motor is in OK shape and the pump itself is good.

Good luck with your repairs!

David Schultz
'93 C4

Spow

Mr Schultz,
Thanks for your response. I've been in touch with my local independant who suggests that a replacement pump is the solution.

Can anyone help with the part number for the High Pressure Hydraulic Pump for a 1990 C4.

Can anyone USA side suggest supplier of used sares for 964's

Thanks
Steve