Hi,

I am having some issues with the brakes of my '94 XJS. the initial problem was a spongy feel. this has improved after running new brake fluid through the system. Using the method of switching the car on ( no starting) and then releasing the bleed nipples in the back. The front has been done by just pumping the pedal the classical way. The brake warning light and ABS light light up on initial pedal operation and go after pressing the pedal deeper, this was also the case before replacing the fluid.
The fault code i get from the ECM indicates the LH rear sensor, though i checked the resistance which implies it should be okay. I will go over the 32 steps test later. But was wondering if anyone had any pointers? Did I probably make a mistake bleeding the system?

Any pointers, greatly appreciated.

 

Hi Aston

You need to Bleed the Low Pressure Side of the System before you Bleed the Brakes or they could stay spongy for ever

The following thread explains the way to do this, although its nowhere near as scary as I made it sound, as it was one of my very first Posts on the Subject, though you do need to be Careful not to get any Brake Fluid on the Paintwork Bleeding the Low Pressure Side of the Teves Mk1V before you Bleed the Brakes

You also seem to be Bleeding the Brakes by the Tried and Trusted Method that I used to use myself, until I accidentally found a much easier way, which was Gravity Bleeding

The easy way to Bleed the Brakes on an XJS An easier way to Bleed the Brakes on an XJS

Its up to you which method you use but Gravity Bleeding gave me the best hard pedal feel I've ever known and was also a lot easier to do

 

Aston,

That's not quite the right way to do the rears on the Teves system. The rear circuiut becomes pressurised when the valve is opened following application of the pedal. Therefore to bleed the rears using the applied pressure, you should:

START AT REAR LEFT, THEN REAR RIGHT, THEN FRONT LEFT, FRONT RIGHT.
ONE PERSON IN THE CAR, ENSURE BRAKE FLUID LEVEL IS FULLY TOPPED UP.
TURN ON IGNITION AND WAIT UNTIL BOTH ABS AND LOW PRESSURE LIGHTS HAVE EXTINGUISHED AND ALSO THE MOTOR PUMP HAS CUT OUT.
THEN, OPEN REAR LEFT BLEED NIPPLE AND HOLD BRAKE PEDAL DOWN, WITH IGNITION ON FOR 15 SECONDS – NO MORE
TIGHTEN BLEED NIPPLE, TURN OFF IGNITION, RELEASE BRAKE PEDAL.
WAIT ONE MINUTE AND REPEAT FROM RESTORING SYSTEM PRESSURE AS ABOVE FOR OTHER NIPPLE – THEN WAIT ONE MINUTE AT LEAST BEFORE MOVING TO FRONT BRAKES – THIS PREVENTS THE MOTOR PUMP FROM OVERHEATING.
AT THE FRONT, ENSURE SYSTEM PRESSURE IS CREATED AND THEN BLEED CALIPERS CONVENTIONALLY WITH IGNITION ON, USING SLOW STROKES AND GO THE FULL TRAVEL BUT DO NOT FORCE.

As OB has mentioned, if you have any concerns as to whether there may still be air in the system, bleed the low pressure circuit first before doing the wheel circuits.

If you're illuminating the lights on application of the pedal, I would start with the 32 electrical tests first.

Good luck

Paul