Brake Pressure Sensors

[harveys]

Originally Posted by sreviz

Thank youThassos.
I will clean the terminals with contact cleaner when I get home.
I have multimeter, I will check the voltage.
Biut Sorry to ask a dumb question .Do I have to check the voltage when the engine running or in key position 2. Also with brake pedals pressed at the same time.

Thank you.

Don't try to clean the pins with anything as you wil bend them as very thin.
just swap the plugs over if the same reading but different sensor then sensor fault.
They should be close to 0 on both sensors and the same when brake pedal is pressed so approx 120 bar max is 180 i think

[harveys]

If you unplug one sensor it will read -21 bar approx on vida

[sreviz]

Ive plugged vida nad found the following results.
Could you please guide me which one is faulty.

Thank you.


Both sensor plugged in without brake pressed
Sensor 1. +10.56
Sensor 2. -.91

Then Both sensor swapped without brake pedal pressed.
Sensor 1 -.91
Sensor 2 +9.49




Then I removed the Left side sensor (when facing the car from front) (closer to engine side).
I call this sensor as Sensor- 1.


The other Sensor which is on right side (when facing the car from front) closer to battery terminal – near side –
I call them as Sensor- 2.

The reading after removing left side Sensor- 1 without brake pedal pressed is
Sensor 1. -.91
Sensor 2. -20.67

And with brake pedal pressed
Sensor 1. 44.98
Sensor 2. 33.93




The reading after Right side sensor- 2 removed (closer to battery terminal)
Without brake pedal pressed
Sensor 1 -20.88
Sensor 2. +9.92

With brakes pressed
Sensor 1. -20.67
Sensor 2. +46.62

[Clan]

Originally Posted by sreviz

Ive plugged vida nad found the following results.
Could you please guide me which one is faulty.

Thank you.


Both sensor swapped without brake pressed
Sensor 1. +10.56
Sensor 2. -.91

Then Both sensor swapped without brake pedal pressed.
Sensor 1 -.91
Sensor 2 +9.49




Then I removed the Left side sensor (when facing the car from front) (closer to engine side).
I call this sensor as Sensor- 1.


The other Sensor which is on right side (when facing the car from front) closer to battery terminal – near side –
I call them as Sensor- 2.

The reading after removing left side Sensor- 1 without brake pedal pressed is
Sensor 1. -.91
Sensor 2. -20.67

And with brake pedal pressed
Sensor 1. 44.98
Sensor 2. 33.93




The reading after Right side sensor- 2 removed (closer to battery terminal)
Without brake pedal pressed
Sensor 1 -20.88
Sensor 2. +9.92

With brakes pressed
Sensor 1. -20.67
Sensor 2. +46.62

it looks like sensor 2 is out a lot in all tests , so change that one first .. It is the difference in pressure between the two sensors which puts the warning message up .

[sreviz]

Sorry. Bit confused.
After swapping the sensors wiring , Ive come to conclusion that one of the sensor is faulty.
But to decide which one is faulty is a bit tricky for me.
If some one could please help me with what reading the sensors should produce if one of the sensor is removed and vice versa.
That will be much helpful for me and for future.

Thank you.

[Clan]

Originally Posted by sreviz

Sorry. Bit confused.
After swapping the sensors wiring , Ive come to conclusion that one of the sensor is faulty.
But to decide which one is faulty is a bit tricky for me.
If some one could please help me with what reading the sensors should produce if one of the sensor is removed and vice versa.
That will be much helpful for me and for future.

Thank you.

You can buy one sensor and try it , then if you still get a problem put it in the other position ... They were £250 each last time i was aware of the price ..

[harveys]

Originally Posted by sreviz

Ive plugged vida nad found the following results.
Could you please guide me which one is faulty.

Thank you.


Both sensor plugged in without brake pressed
Sensor 1. +10.56
Sensor 2. -.91

Then Both sensor swapped without brake pedal pressed.
Sensor 1 -.91
Sensor 2 +9.49




Then I removed the Left side sensor (when facing the car from front) (closer to engine side).
I call this sensor as Sensor- 1.


The other Sensor which is on right side (when facing the car from front) closer to battery terminal – near side –
I call them as Sensor- 2.

The reading after removing left side Sensor- 1 without brake pedal pressed is
Sensor 1. -.91
Sensor 2. -20.67

And with brake pedal pressed
Sensor 1. 44.98
Sensor 2. 33.93




The reading after Right side sensor- 2 removed (closer to battery terminal)
Without brake pedal pressed
Sensor 1 -20.88
Sensor 2. +9.92

With brakes pressed
Sensor 1. -20.67
Sensor 2. +46.62

Have you removed the sensor or just unplugged it ?.
If removed one you will now need to bleed the brakes.
Yes Volvo want close to £275 for one but you can get them for £110 Genuine Volvo part .from Skandix part no 1027602 which comes in a Volvo bag with a volvo sticker and part no 30793669 .
But put cars info in on the site parts finder.

[Clan]

Originally Posted by harveys

Have you removed the sensor or just unplugged it ?.
If removed one you will now need to bleed the brakes.
Yes Volvo want close to £275 for one but you can get them for £110 Genuine Volvo part .from Skandix part no 1027602 which comes in a Volvo bag with a volvo sticker and part no 30793669 .
But put cars info in on the site parts finder.

Good info on cheaper sensors .
In my long experience doing this job you don't need to bleed the brakes if you are quick as a small amount of fluid runs out down from the reservoir which means the air can't get in ...

[sreviz]

Thanks Clan. I've ordered one from breakers.

*Meanwhile I want to be more clear to find out which one is faulty* to reduce the hassle of doing it twice.
I

Removed Left sensor and the reading* are

With out brake pedal pressed
Left side* -20.67****** Right side sensor -0.91
With* brake pedal pressed
Left side* -20.67***** Right side sensor +50.29


Removed Right sensor and the reading* are

With out brake pedal pressed
Left side*** +11.56**** Right side sensor -20.67
With* brake pedal pressed
Left side*** +60.49*** Right side sensor* -20.67

Hope this is much clear reading to understand and.some ine shed some light.

Thank you.

[Clan]

Originally Posted by sreviz

Thanks Clan. I've ordered one from breakers.

*Meanwhile I want to be more clear to find out which one is faulty* to reduce the hassle of doing it twice.
I

Removed Left sensor and the reading* are

With out brake pedal pressed
Left side* -20.67****** Right side sensor -0.91
With* brake pedal pressed
Left side* -20.67***** Right side sensor +50.29


Removed Right sensor and the reading* are

With out brake pedal pressed
Left side*** +11.56**** Right side sensor -20.67
With* brake pedal pressed
Left side*** +60.49*** Right side sensor* -20.67

Hope this is much clear reading to understand and.some ine shed some light.

Thank you.

I would have got both from the breakers ...
The readings have always been a bit confusing , You would expect when your foot is off the brake both would read zero but even on a working system with no faults this is not the case. The actual pressures are not that important , what is important is that both pressures are similar when pressed within a certain range ... just change one and see how it goes , if it is still faulty put the one you took off on the other one ...It is all quite easy ..