Hi having removed the Master Cylinder/Actuator on my Grey XJS, repaired it and then replaced it (full story to follow)

I had to bleed all the Brakes and got a hard pedal but when I turned on the ignition the Red Brake Warning Light on the Dash stayed on.

Even with the Engine running, the Warning Light Stayed on, even though the Brake Pedal still felt hard.

So I very carefully put her into reverse, at which point the Brake Pedal, started to go down and the pedal sort of started to vibrate, so I very quickly put her back into park.

Any ideas as to what I might have done wrong, meantime I am going to bleed them all again.

 

OB,

The Red light illuminates if the brake fluid level is low or if the boost pressure is not within the prescribed range. It also comes on as part of the systems check procedure when you start the car. Because the boost pressure may need to re-accumulate because of your bleeding, it is quite likely that it can take over 30 seconds to rebuild the pressure.

Because the system hasn't illuminated the orange light as well, it's not "seeing" an ABS fault.

My suggestion would be to:

- Re-bleed the brakes as per the defined Teves procedure.
- Check that the fluid level switch on the reservoir cap is connected and the float working properly. They are known to play up.
- Drive the car gently in your drive and see if the red light goes out.

Good luck

Paul

 

Not Quite sure what you have done but I expect a decent job at least, new seals seals and no no leaks, LOL!
Spongy peddles are nearly always from improper bleeding, I don’t know how you did it, so I cannot comment. If its rock solid then should be good.
Sorry No Idea.

Ok my experience on the braking system, I recently changed all the brake fluid, I used a Pella pump (vacuum pump) for oil and got one of boys to keep pumping as the other made sure they kept the reservoir full as I cracked the lines and waited for new fluid to come running out. I start from the right front then to the left front then left rear and right rear, this is just simply working from nearest to furtherest from the reservoir.
After completion the pedal is rock hard and till now still rock hard, but the brake light came one while moving the car of the hoist. Had me puzzled, I simply removed the reservoir cap and gave it a quick tap on the side which soon switched the light off, a bit of air, crud, dirt or just sticky don’t know, but brakes are fine. For the record mine are NON ABS, but if yours are spongy then poor bleeding/leaking are the cause.

 

OB,

I've just thought: If you've removed the whole reservoir and actuator assemble, remember that you've got to bleed the low pressure side of the system first as per manual through disconnecting the LP feed to the pump, BEFORE you bleed the wheel / high pressure side of the system which, as we remind owners, should be done using the Teves not Jaguar procedure.

Good luck

Paul

 

Hi Paul

When I'd tried every thing I could think of, I suddenly thought of that!

There is a small bent pipe that goes straight into the Actuator (about 6ins long) which can be undone and then completely removed.

Which I had to do in order to remove the brake actuator.

Having installed the Actuator, I then replaced the pipe, so I suddenly thought that I might have an Air Lock.

So what I did next was Crack the joint, where the pipe goes into that Brass Thingy and knowing what was probably going to happen, I stuffed loads of rag underneath it.

And also wrapped a load of rag around the joint a few times, then covered the Wing and everything else with bath towels.

Then Switched on the Ignition for no more than 20 seconds.

Then as I removed each layer of rag, when I got near to the joint, it was soaked through with brake fluid, as I expected it would be.

So brake fluid is definitely getting to the Actuator.

Could you give me a link to the Kirby Palm Guide, as I think I must have missed a trick somewhere.

 

Hi Katoh

My XJS has got ABS which is nothing less that a real PIA in more ways than one and so the procedure for bleeding is a bit different.

Its a hard enough job without removing the Brake Actuator, which thankfully most people will not have to do, although taking it out is dead easy.

 

I did try that in the Garage but as I gradually lost the pedal, she nearly came out on her own.

So I really do not fancy trying that again till the Red Light goes out.

 

OB,

A few thoughts and questions:

- If you've got just the Red light on and not the ABS light on, then I think it's the fluid level low at Level 1 in the reservoir, but not so low that it's at failing at the Level 2 test.

- If you've replaced the actuator, you need to bleed the low pressure side before bleeding the wheel circuits. By disconnecting the pipe to the actuator, you're checking on the high-pressure side, not the low-pressure. in theory, if you've got full pressure input of fluid back from the accumulator back to the actuator, then you're ok, but you really must bleed on the low-pressure side first as otherwise an airlock would prevent the pump from pressurising the accumulator.

- Is the pump running up to pressure and then cutting out? If not, this could imply an airlock on the LP side.

- The absence of the ABS light implies that the accumulator is holding pressure.

- Do you know if the ABS light works?

- I would quickly run all the ECM diagnostic tests, particularly 30-32 which will also test reservoir level switch continuity.

- Here's the link to KP's book. Kirby Palm's Jaguar XJ-S Help Book

From memory (which may be wrong!), I don't think he discusses anything on the ABS system apart from replacement of the accumulator. I think that the Jaguar manual should give you all the procedures and diagnostics to crack this one.

Good luck, as always!

Paul

 

Hi Paul

Nothing of much help in the KP from what I could see regarding the Brake Bleeding.

Then a light came on! not in the Car but in my head, as I retraced my footsteps over everything I'd done, which just in case you were wondering was a very, very long walk, from 8 am this morning until now!

Probably not a record though , as the ABS can sometimes be a total PIA!

When I was 'cracking' the Brake Pipe on the High Pressure Side, next to that 'Brass Thingy' to get the Air Out, I did it wrong!

Because that joint was too far away from the Actuator.

The Brake Pipe that I should have 'cracked' was the one that goes 'IN' the Actuator, so this time I watched what was happening as I undid it, while taking care that any brake fluid couldn't spray everywhere.

It is all very obvious now, benefit of hindsight and all that.

There seemed to be lots of Pressure in the System, for as soon as I cracked the joint, some bubbles of Air came out, followed by a high pressure jet of Brake Fluid. (All good as I was ready for that to happen)

Then Back in the Car I turned on the Ignition.

Red Light 'ON' ABS Light 'ON' Pump Running.

I was planning that I would let it run for 60 seconds MAX as I've heard you can burn out the Pump.

But within a few seconds the ABS Light went out and 20 seconds later, So did the Red Light!

So we could be back in the game!

Seeing as She's still Jacked Up I'll leave her overnight, so any minute bubbles in the Reservoir can escape and then Tomorrow I'll bleed the brakes again.

Then if all is OK I might risk a short Test Drive, round the block a few times to see how it goes.

You won't believe what I did to the Actuator, or maybe you would!

The ABS though is still making me nervous!

 

OB,

That's good news! It sounds as if you did have air on the low pressure side. As you've let air get in before the pump by removing the reservoir, you MUST bleed on the low pressure side to the pump, not on the input of the high pressure from the pump back to the actuator, before you bleed the wheel circuits.

Turn off the ignition, disconnect the input of the low pressure pipe from the reservoir where it enters the pump, NOT the HIGH pressure input from the pump back to the actuator (which I think is the one you've been doing). Get a jar and let fluid flow from this pipe. Whilst the flow is constant, connect the pipe back to the pump. Top up the reservoir. Then turn on the ignition and let the accumulator pressurise back up.

There's no need to crack the pipe that you've been doing on the high pressure input to the actuator. If the low pressure side is bled properly and the accumulator builds up pressure, then the correct Teves procedure will bleed the high pressure side.

Until tomorrow....

Paul

 

Hi Paul

Why wait for Tomorrow

Its all gone Wrong Again!

I thought that I would give it another try to make sure it wasn't a fluke and this is what happens.

All the lights come on except the Red Brake Light.

The ABS light comes on for a few seconds, then goes off again like its meant to.

But the Red Brake Light does not come on at all.

If I start the Engine, then All the lights go out, including the Red and Yellow Strip Warning lights at the Top.

I've checked the Brake Pump fuse and that's OK but the Reservoir was nearly empty, so I refilled it.

But what has happened to the Red Brake Light?

 

OB,

Assuming that the circuit is working and the bulb intact etc etc, it COULD be that the fluid level is checked so quickly, and the accumulator pressure has been built up by your previous ignition cycle and not dissipated, so there is no need for the pump to run to get the pressure within limits.

So although I thought it would expect it to come on and immediately extinguish, MAYBE its possible that it doesn't come on as part of the startup sequence if both conditions are already met. In order to verify this, you could try to "lose" the pressure by pressing the brake pedal 20 times after the ignition is off. Then turn the ignition back on and see if the pump starts up again (and the light comes on until pressure is achieved).

Either way, make sure you bleed that LP side of the pump.

Paul

 

Hi Paul

That sounds like it could be a feasible explanation, as not only is there no Red Brake Light, you can't here the Pump running either.

Or maybe the Pump has burned out, though I was very careful not to let it run for too long.

I also reckon you are right about the Low Pressure Side, so I'll give that a try Tomorrow and see what happens.

 

Hi Paul

Got to run a few errands before I get back to work on the Brakes but when I bleed the 'Low Pressure Side' where the fluid goes into the Pump, would I be correct in assuming that you have to turn the pump on for or a few Seconds, or does it just flow out by gravity?

 

Could I get some opinions about the "brake" warning light on the cluster? Specifically, the first part of the above response. I've got the red brake light on but no ABS light, fluid is filled high, and the pedal and brakes feel normal.

My car is a 89 and so doesn't have the fluid sensor on the top of the reservoir cap (I'm not exactly sure where the sensor is).

thanks!

 

Andy
If you have the red brake warning light on, it can mean one of at least two things. Low fluid (and if you have ABS then I do not know where the fluid level sensor is or even how that system works from the low fluid angle, but someone will) OR, that the handbrake microswitch is badly adjusted/the handbrake lever is not fully off. The microswitch is under the plastic cover on the handbrake fulcrum and may need the seat out to get at it. On a non-ABS car, the handbrake when on with the ignition on, lights the brake warning light to warn the owner that the HB is on. If the microswitch is out of adjustment, releasing the HB can leave the switch still in contact.
Greg