89 XJS, hard brake pedal, wont stop
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89 XJS, hard brake pedal, wont stop
Hello again, it has been so long since my original post that I decided to start a new thread. My 89 XJS had a brake pull to the right last fall, when I tried to use it this spring after being in the garage all winter, it had a very hard pedal and wont stop at all. I tried bleeding the brakes as recommended by members here but cannot get fluid out of the rear calipers and the only brake that I can get any fluid out of is the right front. Pedal only sinks when I open that bleeder, all other calipers the pedal stays hard and no fluid. Pump runs as it should. I am not sure what to do next. Thank in advance.
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There are quite a number of reasons why your Brakes are not working.
(1) When you turn on the ignition does the ABS light go out
(2) How many Seconds (roughly) does it take to go out
(3) How did you bleed the low pressure side of the System (ie did you bleed the brake pipes on the master cylinder actuator)
It could be that you need a new Accumulator Ball (The Black Pressure Ball) or maybe even a new Brake Pump.
Hard to say at this stage, so best try and eliminate the other options first.
Did you ever manage to get the Brakes working before?
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A quick peek reveals nothing in the sticky thread/FAQ sections covering common ABS problems, fixes, and service procedures. Or am I just not seeing it?
I'd write something up myself but I'm not well versed or experienced on the subject.
Cheers
DD
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A little more information,
1. ABS light comes on and pump runs approx 2 second and then the light goes out.
2. Pump runs and lights are on anytime the brake pedal is depressed, only stop when
brake is released
3. Brake calipers and hoses were replaced last fall due to the pulling problem, they
made no difference.
4. Brake were bleed at that time as normal at the bleeders on the calipers. Car was
drivable but with a pull to the right until it sat over the winter, no longer driveable.
5. New problem just discovered, after working the brake pedal, the left front caliper will
be stuck until the bleeder is opened, yet the right front caliper behaves normally?
6. Checked trouble codes, "21" stored. Main valve failure?
1. ABS light comes on and pump runs approx 2 second and then the light goes out.
2. Pump runs and lights are on anytime the brake pedal is depressed, only stop when
brake is released
3. Brake calipers and hoses were replaced last fall due to the pulling problem, they
made no difference.
4. Brake were bleed at that time as normal at the bleeders on the calipers. Car was
drivable but with a pull to the right until it sat over the winter, no longer driveable.
5. New problem just discovered, after working the brake pedal, the left front caliper will
be stuck until the bleeder is opened, yet the right front caliper behaves normally?
6. Checked trouble codes, "21" stored. Main valve failure?
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Hi acauto
I agree with Daim, it does sound like a problem in the ABS Valve Block but even if it isn't, its worth doing anyway.
But before we get in to that are you 100% sure that one or both of your Calipers are not Sticking, as it kinda sounds like at least one of them may be.
And in order to get your Brakes working, it has to be done a step at a time or it will bite you on the backside when you least expect it.
I had a Stuck Caliper and it nearly set fire to the Car.
So if you are in any doubt, you could either put in New Pistons and Seals or else go Service Exchange.
As otherwise anything else you do may not be able to fix it.
I agree with Daim, it does sound like a problem in the ABS Valve Block but even if it isn't, its worth doing anyway.
But before we get in to that are you 100% sure that one or both of your Calipers are not Sticking, as it kinda sounds like at least one of them may be.
And in order to get your Brakes working, it has to be done a step at a time or it will bite you on the backside when you least expect it.
I had a Stuck Caliper and it nearly set fire to the Car.
So if you are in any doubt, you could either put in New Pistons and Seals or else go Service Exchange.
As otherwise anything else you do may not be able to fix it.
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The calipers do not stick. They are new as are the hoses but beyond that, the way you know is by the fact that when you open the bleeder and release the hydraulic pressure the rotor turns freely. If the caliper were sticking then opening the bleeder would have no effect. The brake fluid has not been changed entirely, just what was purged during the caliper and hose replacement.
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I agree that the problem is in the ABS unit. Just not sure what to do next. I found a service bulletin related to the abs unit but I have not attempted the service. I also mentioned the code "21" that was stored but the description is very general and
I have found no detailed testing procedures. First digit "2" is for a "valve failure" and the second digit "1" is for "Main Valve"
I have found no detailed testing procedures. First digit "2" is for a "valve failure" and the second digit "1" is for "Main Valve"
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Ok in that case on the assumption that you have bled the Air out of the Low pressure side of the Master Cylinder Actuator.
The next thing to do is to Check the Valves are working in the ABS Valve Block.
You don't have to pull anything apart (YET!) as the Valves can be Checked externally.
In the ABS Valve Block which is Bolted on the Side of the Master Cylinder Actuator are 6 Valves, all wired up together.
This has got a 7 Pin Plug on the Side.
Which will pull out after you take off the Clip.
One of those Pins is Common and the others go to each valve.
This Pic will show you what the Valve Block looks like inside.
The XJS Valve Block uncovered
The Next thing to do is Test it with your Meter (No need to take the Cover off at this Stage)
Here is how you do the Test (With Thanks to RennsportKC) then come back and we can go from there.
RennsportKCJaguar XJS ATE ABS repair... - RennsportKC
The next thing to do is to Check the Valves are working in the ABS Valve Block.
You don't have to pull anything apart (YET!) as the Valves can be Checked externally.
In the ABS Valve Block which is Bolted on the Side of the Master Cylinder Actuator are 6 Valves, all wired up together.
This has got a 7 Pin Plug on the Side.
Which will pull out after you take off the Clip.
One of those Pins is Common and the others go to each valve.
This Pic will show you what the Valve Block looks like inside.
The XJS Valve Block uncovered
The Next thing to do is Test it with your Meter (No need to take the Cover off at this Stage)
Here is how you do the Test (With Thanks to RennsportKC) then come back and we can go from there.
RennsportKCJaguar XJS ATE ABS repair... - RennsportKC
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