1991 Jaguar XJS ABS Accumulator

1991 JAGUAR XJS
48,000 MILES • V12 • 2WD • AUTOMATIC
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ITSALLGOOD
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Everytime I step on the brake pedal, the ABS pump will come on, if I keep holding the brake pedal, after about 5 seconds the brake light will come on, then after another 4 seconds the ABS light will come on also. After I remove my foot from the pedal, the pump wil keep running, and about 6 seconds later - the ABS light will turn off (pump still running), then about 5 seconds later the Brake light will turn off (pump still running), then about 6 seconds later the pump sounds like it is working against pressure and it will stop running. Everything is happy untill I get to the next stop sign, then the whole story starts over again. If I need to wait at a stop light (holding the brake) - the pump just keeps running (I don't think thats good for the pump).

I'm pretty sure that I need to replace the accumulator......looks easy enough, just unscrew the old one and screw the new one in?

There is a BIG warning on top of the old one, "Do Not Remove. High Pressure Brake Fluid"
Well, I'm pretty sure that if I pump the brake a few times - there isn't much pressure left in there. Anybody replaced one before?
Jun 16, 2008 at 7:44 PM
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2CARPRO JACK
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You need to pump the pedal at least 20 times, then the brake pedal will get hard and it should be all good at that point
Jun 19, 2008 at 7:45 AM
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ITSALLGOOD
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Thanks for the information!
If I replace the pump and accumuator, I'm pretty sure that I'll need to bleed the system, is there a special procedure for that? - or will I need to just bleed each wheel - same as any other car?
Jun 19, 2008 at 9:36 PM
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2CARPRO JACK
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According to my software there is no special procedure, start right rear, left rear, right front , left front
Jun 20, 2008 at 7:32 AM
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ITSALLGOOD
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...This car does NOT have brakes on the rear wheels!
Just 2 monster calipers on the front wheels. Bleeding the lines seemed easy enough. Not sure exactly if the accunulator is bad or the valve block? If someone holds the brake pedal I can hear the brake fluid flowing throught the valve block for about 7 or 8 seconds before the pedal goes hard. Is there anyway for the valve block to be open so that the brake fluid can flow through it so easily? Or - is the problem just that the accumulator is weak? I'm thinking more that the valve block is bad - because I do NOT need to pump the pedal to releive the pressure from the accumuator. All I need to do is hold the pedal for about 10 seconds, and all the pressure will be gone.
Jun 23, 2008 at 3:45 AM
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2CARPRO JACK
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The rear brakes are "inboard" on that car, they are next to the center of the diff.
I suggest you go here

https://www.2carpros.com/diagrams

In there you will find the complete diagnostic chart for your ABS problem, you can look it up by symptom
Jun 23, 2008 at 7:21 AM