Hi guys!

I'm new on this forum.

Recently, 3 weeks a go, I have been facing the fallowing situation: when I braking to stop at a traffic red light, the car's wheels remain braked for a 2-3 seconds, after I lifted my fost off the brake pedal. Is not hillasist.

I performed a test on an inclined road and after 2-3 second-hand the wheels are released and the car stars moving on its own. I noticed this behavior only when the speed drops to 5-10 km/h before the car finaly stops moving.

Yersterday I went to a car service, no Ford service, that confirmed the following aspects, after they put ther car on elevator and lift it: when pressing the brake pedal and then lifting the foot off it, the wheels remain locked diagonally, left rear and right front, for approximately 2-3 second. Then wheels can be turned easily.

I would like to point ouț that no lights is on the dashboard.

Also the service engineers found that the pistons on the calipers are working normally and there are no traces of rust would prevent them from returning from the race.

If enyone has faced similar symptoms, what was broken? The brake pomp, the ABS modul, other component? 

Thank you very much!

I think this will be the master cylinder.  To test, remove the fuse for the ABS pump to ensure that can't be electronically holding the brakes, then press the pedal and see if the brakes remain locked.

Master cylinder?

What is it exactly?

Thank you!

1 hour ago, Almo88 said:

Master cylinder?

What is it exactly?

Thank you!

The master cylinder fits behind the brake pedal in the engine bay, under the brake fluid reservoir. 

When you press the pedal, that pushes on the cylinder to create pressure in the brake pipes.  That pressure then goes on to push the pads in the calipers.  When you release the pedal, it should release the pressure in the system. 

It is split in two halves so that if one side fails, you still have brakes on the other two wheels.  They are diagonal to give you controlled braking in that event.

6 minutes ago, TomsFocus said:

The master cylinder fits behind the brake pedal...

Thank goodness you were on hand, Mr Google wouldn't have had a clue on what a master cylinder is 🤣

Vă mulțumesc fiecăruia dintre voi pentru sprijin. 

Exista posibilitatea de a continua în mod privat discuția pt a nu plictisi membrii? 

Să înțeleg că acest cilindru este diferit de pompa de franare, ca cea din link? 

https://www.autodoc24.ro/brembo/1660296#pompa-centrala-frana

Mecanicii de la reprezentanta service  Ford merg pe varianta defectarii modului ABS, ( înlocuire destul de costisitoare) conform descrierii simptomelor.

Va mulțumesc!

2 minutes ago, Almo88 said:

Thank you to each and every one of you for your support. 

Is it possible to continue the discussion privately so as not to bore the members? 

Am I to understand that this cylinder is different from the brake master cylinder like the one in the link? 

https://www.autodoc24.ro/brembo/1660296#pompa-centrala-frana

The mechanics from the Ford service representative go for the ABS mode failure option, (quite expensive replacement) according to the description of the symptoms.

Thank you!

Don't worry about boring members.  

I did mean the brake master cylinder, it is exactly the same part as in your link.

I don't think this is a fault with the ABS module personally.  That can brake each wheel separately.  I don't know why it would brake 2 diagonally if it was faulty.  However, I cannot be 100% sure.

Can't collapsed flexi hoses cause this issue?

12 minutes ago, DaveT70 said:

Can't collapsed flexi hoses cause this issue?

I would expect those to only affect one wheel at a time.  Though I wouldn't rule it out now you've mentioned it.

TomsFocus, just a little comeback. 
The brakes work on all 4 wheels.
But on the wheels on the diagonal, left rear and right front, they do not disengage when stopping, the pads do not retract (pistons and calipers work easily), they remain braked for 2-3 seconds. 

After the 2-3 seconds, if the car is on a road with a slope, it starts moving smoothly. This also applies if I accelerate/start from a standstill.

Thank you and I hope I am not too stressful.

If it's not the flexi hoses I'd suspect the ABS module before the master cylinder

Well, that looks like two against one for ABS module.  Personally, I still don't believe it's that due to the diagonal split. 

If you remove the main fuse for the ABS pump (large one, probably around 50 Amp) that should stop the ABS working altogether.  Then we will know whether this is a fault on the hydraulic side (master cylinder or pipes) or whether it's on the electrical side (ABS module).

Guys, 
Based on the opinion of the engineer from the Ford service representative that the symptoms indicate a failure of the ABS module, I wonder why nothing lights up on the board to indicate a failure on the ABS? Today's cars have become very complex.

Just to add my two penneth on the thoughts of the brake problem.

I think it is likely to be an ABS pump problem, BUT, you should do what Tom has said and remove the fuse for the ABS system and see if the problem of the brakes being held on, stops happening.

Would suspect a sticking secondary piston in the master cylinder, under normal breaking none of abs valves should be operating.

On a diagonally split master cylinder there are two inline pistons, the primary nearest the brake pedal and the secondary furthest from the brake pedal. If the primary piston was to stick then the secondary would stick as well and all four wheels would not release. During normal braking when the abs is not operated brake fluid is free to flow in both directions through the abs module. Hope that all makes sense but I stand to be corrected.

I carefully read your theory and I admit that my limited knowledge of mechanics makes me ask you directly: did the brake pump (master cylinder) or the ABS module fail? Thank you very much!

I think for the abs unit to be at fault there would have to be more the one faulty valve as each wheel has separate valves within the abs unit. Hopefully you have tried what Tom suggested pulling the abs fuse and trying that to see if it makes any difference. If it makes no difference, which I don’t think it will then I know what I would be trying first and that would be the master cylinder. I would be tempted to carefully strip the master cylinder to see if it was sticking. But to answer you question I don’t know for sure which has failed, but still think it’s most probably the master cylinder.

I have not yet tried the solution proposed by Tom, the check by removing the fuse related to the ABS module. I have a fear of not breaking something else. It would be the F7 safety. But F8 and F19 also refer to the electronic system and ABS.

In addition, I don't know how the on-board computer will behave if it is completely without power. May require checking with a tester?

Anyway, on Friday morning I have an appointment at a car service, not the Ford dealership, where we will start with replacing the brake pump/master cylinder.

I was thinking of first proposing to the mechanics a bleeding of the braking system and replacement of the brake fluid.

I will definitely keep you updated on the progress of the repair.

 

Dear all, 

I checked the master cylinder today. Prior to the operation, the battery terminal was disconnected, practically the ABS module was bypassed.

After testing the brake, which is a mechanical module that does not depend on the electricity supply, the diagonal wheels remained locked for a few seconds. In the master cylinder the pistons work easily, the brake system has been bled. Brake fluid was coming out of the valves.

Conclusion: the ABS module, which is quite expensive approx. 1200 Euro, it is broken.

I thank each of you for the messages and the desire to help me.

Closed topic!

Having read this thread, I’m pleased that the OP has reached a good conclusion, which was one of the suggestions raised by members.  I think it’s great that we can help people here, even members from other countries.  Well done folks. 

Hi guys!

Finaly after 2 months of documenting and checking the components of the braking system, but also with your help and 2 weeks for waiting the order delivery by Ford service, I replaced the ABS module with an original one from Ford. Now the car works normally. 

The cost of the part and the labor was 1650 euros, that is 10% of the car's current market value.

I have some rhetorical questions:

How is it possible for a part like the ABS module to break down after 73,000 km traveled under the conditions of performing an exemplary maintenance only at the Ford service dealer?

Is there a possibility that the defective module has a manufacturing defect that caused the failure in the first 5 years of the car's use?

Can the ABS module be repaired?

Could I contact Ford to recover part of the costs if it turns out that the ABS module had a manufacturing defect?

Thanks to each of you for the advice.

4 minutes ago, Almo88 said:

How is it possible for a part like the ABS module to break down after 73,000 km traveled under the conditions of performing an exemplary maintenance only at the Ford service dealer?

Why do some people suffer heart failure and die at the age of 43 when they've always been healthy ?

Things break, its just a fact of life. Your 2018 car is 7 years old, Ford didn't sell it with a lifetime warranty. Your ABS unit has failed and that's very unfortunate, but it's not a common occurrence.

You are right.

But you know what's frustrating?
During the entire 5-year warranty period that I performed the technical revisions in the Ford services, not a single engineer mentioned that I need to replace the brake fluid, which seems to be to blame for some deposits on the ABS hydraulic pump valves.

I hope that this topic will be useful to those who have the same symptoms in the car as I had.
All the best!

 

Personally (especially having an 13 YO car) I'd always look at either a repair (there are multiple firms offering ABS repairs with lifetime warranty), a used part or OEM quality replacement unless it was absolutely necessary to buy Ford. I know they are responsible for holding stock but I suspect they sit in committee and decide the price based on how much they can rip owners for!
AND do as little dismantling as possible - diagnosis with testing not guessing is the key?
Your views may differ