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I am guessing perhaps incorrectly that at some stage during the Caliper swap that the Reservoir may have run dry, where in the event that this happened then you will have to Bleed the Low Pressure Side of the System and then once having done so re-bleed those Front Brakes again
And so just out of interest, did the Reservoir ever run dry?
I have an isolation switch... would this have cleared the fault?
I did turn on the ignition and pump ran stopped, ABS light went out etc.
Then I ran this blink test... 3 fashes - twice
rear sensor?
It hardly takes any time to Bleed the Low Pressure Side of the system
IGNITION OFF! AT ALL TIMES!
(1) Have a Jar and some Rag standing by and then Cover all exposed Paintwork with Old Towels and also have a Bucket of Soapy Water close at hand to Sluice down any accidental Brake Fluid Spills
(2) Pull the Locking Pin out of the Plastic Elbow of the Brake Pump
(3) Jiggle and Pull the Plastic Elbow out of the Brake Pump being Careful not to break it, as its made of very Brittle Plastic
(4) As soon as you pull the Elbow out Brake Fluid will Start to run out but as its not under pressure put your finger over the end to control the flow Brake Fluid as you catch it in the Jar
(5) Let the Brake Fluid flow into the Jar until it runs Bubble Free (just takes Seconds) and then while the Brake Fluid is Still running out Put the Elbow back in the Brake Pump and lock it in place with the Pin
(6) Its a bit of a messy process so mop up any Brake Fluid Spills with old rag and wash down with a little water but try not to Spill any Brake Fluid so you don't have to do that
That's all there is to it!
In a 'Nutshell' you are Gravity Feeding Brake Fluid from the Reservoir to the Brake Pump via the long Metal Tube that runs across the Back of the Firewall while getting rid of any Air Bubbles just before it goes into the Brake Pump at the Plastic Elbow end
This must be done 'on the fly' while the Brake Fluid is still flowing, as you push the Elbow back into the Brake Pump
The Brake Fluid is only Gravity Fed, so its not going to come squirting out and you can put your finger over the end of the Plastic Elbow if you want to stop the Flow for any reason
Its Best to have an Assistant (who knows what they are doing) to keep the Reservoir Topped up as you do this, as if any Air gets in then you will have to do it all over again!
Do not let the Reservoir run dry
Be very Careful not to let any Brake Fluid drip on the Paint Work, or it will just Strip the Paint off in an instant and potentially ruin your Car
Don't Panic its not quite as Scary as it sounds as the Brake Fluid is flowing out under Gravity and Not under Pressure!
Then having done that go and re-bleed all the Brakes all over again!
I Know its a bit of a PIA but if there is even one Bubble of Air in the System, then it will never be right
Either use the Tried and Trusted method described by Paul (ptjs)
Or My Gravity Bleeding Method
But don't Mix and Match them either use one or the other but after Gravity Bleeding the results of this are so good that I will never do it any other way
As for the Master Cylinder Actuator being at Fault I don't know but Paul (ptjs) might, as all I can tell you is that they seldom go wrong
Good Luck Duke!
Don't Panic! as Bleeding the Low Pressure Side can seem a little bit Scary
And don't drip any Brake Fluid on the Paint!
Last edited by orangeblossom; 10-04-2022 at 06:45 PM.
If it turns out that you've got a problem with the Master Cylinder Actuator, then no amount of Bleeding is going to fix it
So it could be that one of the Valves inside is either Sticking or you have a Broken Wire inside the Valve Block
With any Luck you have fixed it by now but if not I have done a Video on How to Test the Valve Block to make sure that they are all 'Clicking' like they should
- The reset of the blink fault codes is done by driving the car above 19mph. I guess that's a problem right now if it's undriveable with the brake issue.
- Remember also that the system can only show you one of each series of fault codes until you've cleared it. For example, you might have a 33 and also a 34 code, but it will only flash the 33 code until you've fixed the problem. Then if the 34 code still exists, it will flash the 34 code.
- Most sensor fault codes are either caused by debris in the toothed sensor ring or else problems in the wiring connectors
- In theory, a soft pedal can not be caused by a wheel sensor problem. A soft pedal is air in the system somewhere or else an Actuation seal problem (less likely)
- If your air is in the Actuation Unit, or in the High Pressure circuit from Accumulator to Actuation Unit, you can't remove it by caliper gravity bleeding. You have to remove it by the recommended bleeding routine.
I know that a rebuild of the caliper can't cause air to enter the Low Pressure side of the High Pressure circuit. BUT you first talked about a soft pedal before you rebuilt the caliper which COULD have been air in the Low Pressure circuit. Therefore, I would start the whole bleeding process (sic!) again by starting with the Low Pressure Side, then use the Teves procedure for the rear wheel circuits, then for the front wheel circuits. Just to reinforce, you HAVE to use that process for any air in the High Pressure side, the Actuation Unit, or the lines from the Actuation Unit to the calipers.
right - update.
I have brakes... still spungy but there are brakes.
I can pump the brakes rock solid with a few pushes so there is still air in the system BUT there are brakes which is a thousand times better than before.
I must have bleed the L/P side 5 times..... not so scary now that I have mastered that, followed OB's advice - tin foil underneath and a small cup to catch the brake fluid.
It is a small stream the runs out, I mean a small slow stream... is that correct? Never noticed any air bubbles. When I lost patience a couple of times and pumped the peddle to quickly it blow air back in to the LP side.. I could hear it.
So start again...
Now that I have brakes with air in it I need to bleed the whole system again...lol
start at the back left, back right, front left and front right....
Sound like a plan?
As Paul said - If your air is in the Actuation Unit, or in the High Pressure circuit from Accumulator to Actuation Unit, you can't remove it by caliper gravity bleeding. You have to remove it by the recommended bleeding routine. How is this done? Now that I have brakes with some air in the system... is this needed?
I know that a rebuild of the caliper can't cause air to enter the Low Pressure side of the High Pressure circuit. BUT you first talked about a soft pedal before you rebuilt the caliper which COULD have been air in the Low Pressure circuit. Therefore, I would start the whole bleeding process (sic!) again by starting with the Low Pressure Side, then use the Teves procedure for the rear wheel circuits, then for the front wheel circuits. Just to reinforce, you HAVE to use that process for any air in the High Pressure side, the Actuation Unit, or the lines from the Actuation Unit to the calipers.
I'm sure you'' have done the LP side correctly. Not a lot of fluid will flow as it's a fairly small pipe with almost zero gravity on it. As long as you've got a small steady stream of fluid with no air bubbles, you've done it fine.
Pressing the pedal whilst you have the LP pipe disconnected will have absolutely no effect on that fluid flow. The pedal is connected to the Actuation Unit. The LP side to the pump is not connected to the Actuation Unit at all, so the pedal has no impact on that circuit.
I'm confused by the colour of your green fluid in that photo? Brake fluid is not that colour in the UK. Maybe it's different in the US?
You MUST now bleed the 4 wheel circuits using the Teves routine. This is important. Remember that the pedal pressure does not push any fluid to the back wheels! I know that's counter-intuitive but it's true! The fluid is sent to the back wheels by the stored pressure in the accumulator via a port valve to the Actuation Unit which is opened when the brake pedal is pressed. So you have to have a powered circuit to bleed the rear brakes. I'm sure you know it, but here's the routine:
Bleeding Teves brakes
Two people required.
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, and ensure it does not run too low during the procedure.
Turn on ignition and wait until both abs and low-pressure lights have extinguished and also the abs motor pump has cut out.
Then open the 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, after from restoring system pressure as above, for the right side.
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 via the pump, and then bleed calipers conventionally with ignition on, using slow strokes and go the full travel but do not force. Once the left side has been done, again wait one minute and then restore system pressure before doing the right side.
Ensure brake fluid level is checked and topped up after each caliper is bled.
When you Bleed the Low Pressure Side, it normally takes just a few seconds. where the amount of Fluid pouring out is most usually just enough to fill an Egg Cup
So if you got Two Big Cup Fulls out, you may have got Air in the System but only you would be able to know that for sure
When you turn the Ignition on from a Stone Cold Start up, how many seconds does it take for the ABS Light to go out and for the Brake Pump Light to go out and eventually stop running?
There may be a Clue in there somewhere
Like Paul (ptjs) I've not seen any Green Brake Fluid before
But I am using clear stuff this time.
Drove the car yesterday and everything was good.
Brakes felt good.. I did notice if I pumped the brake 1-2 times it when like rock solid like wood.
Other wise the peddle had some feel to it which I much perfer.
I plan to do the caliper on the other side now... once that is done I will be bleeding again.... just as Paul says... !!!!
And I wanted to do the one side first to make sure there were no faults...
Surely the only Green Fluid is LHM which is the mineral fluid used in some Citroens and Rolls Royces? I'm really not sure you should be using a mineral oil in a standard or Teves Jaguar braking system?
Hi Paul - no this is just standard brake fluid made green so you can see when it is flushed though the system.
SCA Brake Fluid DOT 4 500mL Size 500mL Oil Composition Full Synthetic Boiling Point (Wet) 155°C Boiling Point (Dry) 260°C DOT DOT 3, DOT 4 SAE SAE J1704 ISO ISO 4925 AS AS 1960.1
I have moved to a Castrol - clear product so I can see when the green stuff is gone... pump charge time is 10-15sec now.. best ever!
At the risk of sounding worrying, that doesn't sound quite right. IMO,10-15 secs sounds way too short for a full pressurisation of a discharged accumulator.
The only way to properly assess the effective operation of the pump, accumulator, and relief valve is to fully discharge the accumulator first.
So, turn off ignition. Press brake pedal 25-50 times. The pedal will get increasingly harder.
No turn on ignition and count how long the pump runs for.
Hi Paul... no this is from a pressurized system.... when you turn the key on.
Question...does the loop go at the bottom?
Doing the other side, just completed... and putting pads back in..
Not sure what way I did these on the other side....
So just checking for this side, then I will check the other side Loop at the bottom of the caliper? Just checking...
10-04-2022, 03:58 AM
