V 70 Brakes - ABS System

Post by **manovlov** » 10 Jan 2018, 14:10

I understand. I will see a repairer tomorrow. A friend of mine speaks about the noise and think it may be the brake booster ...

Does it talk to anyone ?

Manov

Post by **scot850** » 10 Jan 2018, 16:06

Like Rick I am not sure it has anything to do with the master cylinder or booster.

Typically if the booster fails you get no pressure so you need a lot of pedal pressure. There is a valve in the booster that can fail. and that gives the same failure mode. There is no vacuum pump for the booster either on P80's and again if there was the same issue would occur.

If the master cylinder fails it leaks so the fluid level would drop. If it is dropping fluid level but no sign of the fluid, it is leaking into the booster unit from the rear seal.

When the ABS kicks in you will get a rapid 'vibration' from the brake pedal. If it is kicking in and out the issues are possibly 2 or 3.

1) ABS module is failing and you get random failures and ABS can kick in randomly.
2) ABS sensors in the 4 wheels could be damaged. These can usually be tested by resistance values.
3) The ABS rings in the wheel hubs can get a build up causing the ABS to react as it is confused, or the rings can rust and crack also causing issues with ABS sensing.

Neil.

Post by **manovlov** » 10 Jan 2018, 22:24

Hy Neil,

As a newbie, I'm not sure of anything. And I have to control each part the one after the other to find the solution.
I will remove the ABS module this afternoon and send it to the be repair and control the resistances values. I must begin by somewhere.
I will keep you informed about this issue.

I do thank you all so much to have answered "present" on this post. I feel less lonely.

Didier.

Post by **scot850** » 10 Jan 2018, 23:20

You are welcome and we will do our best to help you through this. Everyone has to learn somewhere and the folk on this website are the best as I have been fortunate to find out over the years!

Good Luck!

Neil.

Post by **manovlov** » 11 Jan 2018, 06:44

Hy Neil and you all,

ABS module is out and I go to the post office ! On his way to ReCar, to Sweden.

Thanks again

Didier

Post by **scot850** » 11 Jan 2018, 08:23

That is good/bad news but hopefully that is the root cause. Let us know if it is the fix once you get it back and fitted!

Neil.

Post by **manovlov** » 11 Jan 2018, 09:32

Allright.

Didier

Post by **manovlov** » 30 Jan 2018, 09:39

Hy Everybody,
I come back to tell the end of the story. I phoned to Daniel from Recar in Sweden. I sended him the ABS module : price was clear and the guy is really cool. An address to keep preciously. From France to Sweden 11 days by post office - from Sweden to France 3 days, stamps for the same price : ?

I've just re installed the module and it works at the perfection. Thanks you for your advice Neil : Well done ! I keep a beer in the fridge for your next trip to France !

I do thank all the ones who came to help on this post. You are all some nice buddies.

Manovlov.

Post by **abscate** » 31 Jan 2018, 06:48

I will pass on the beer but Les Raviolles des Royans would be great!1

Post by **manovlov** » 31 Jan 2018, 10:11

Ok let me see if it may be possible to send some. If interested, contact me by PM.

Manovlov

V 70 Brakes - ABS System

Re: V 70 Brakes - ABS System