Morning all,

Went to drive my ST today and the brake pedal was hard, it works but I can only assume something has failed in the booster system. So my question, how can I check the system and what should I be looking for? I am usually capable of doing some of the easier jobs on my cars (usually with the aid of a youtube video). If its beyond my capability, I'll get a garage to look at it but wanted to see what I can do first.

Cheers in advance.

Hi,

It isn't common for servos to fail on modern cars. Really the only thing you can check is the vacuum pipe going into the servo.

The pipe appears to be intact with no damage. I've checked the whole length down to the valve and it all appears fine. Could the valve be the issue or is it likely to be the servo?

Could it even be the vacuum pump that is at fault? Is there a way to check that it is working as it should be.

Cheers

12 minutes ago, Mattinho18 said:

The pipe appears to be intact with no damage. I've checked the whole length down to the valve and it all appears fine. Could the valve be the issue or is it likely to be the servo?

Could it even be the vacuum pump that is at fault? Is there a way to check that it is working as it should be.

Cheers

If it was the vac pump then the turbo wouldn't boost either, so we can rule that out.

I'm not sure where the servo pipe connects on this engine. It looks like the pump doesn't have a second take-off for the servo (as the 1.0 EcoBoost pump does), so must connect to the pipework further down? Is that what you mean by the valve?

You can disconnect the pipe from the servo, then run the engine and put your finger over the end of the pipe. You should be able to feel whether it's sucking a vacuum at that end of the pipe or not.

I can't remember the last time I saw a servo fail on a modern car, so I would be surprised if that is faulty, but of course anything can break so I wouldn't totally rule it out yet.

Okay, I am assuming the check engine light would show if there was a lack of boost? (Update: it has boost still)

Here is where the vacuum pipe joins the servo (not mine, taken from google). Am I right in thinking I could damage the pipe if I pull it off due to its age?

This is the valve I mentioned that attaches to the pump. (Again, not mine. Taken from a youtube video)

Apologies for the questions, I like to try and fix things myself and learn as I go.

2 hours ago, Mattinho18 said:

Okay, I am assuming the check engine light would show if there was a lack of boost? (Update: it has boost still)

Here is where the vacuum pipe joins the servo (not mine, taken from google). Am I right in thinking I could damage the pipe if I pull it off due to its age?

This is the valve I mentioned that attaches to the pump. (Again, not mine. Taken from a youtube video)

Apologies for the questions, I like to try and fix things myself and learn as I go.

Hmm, ok. That's different to the parts diagram I checked. We don't see many 2.0 EcoBoost faults on here so I'm not as familiar with these engines as others.

If there is only one take-off from the pump, then that must split somewhere to feed the turbo wastegate as well as the brake servo. It's possible there's a one-way valve towards the servo end that's failed. (Edit - I can see it on the picture now, brake servo and boost supply split at that valve right above the pump).

Removing the pipe connector from the servo could break it, but it should be ok as long as you're careful.

Yeah you are correct. The valve in the second pic is where it spits to both the servo and the turbo. If that has failed, would it not effect the brakes and the turbo?

I'll try and pry the pipe off, the servo isnt working so can't make it much worse. Just to confirm, if I feel suction from that pipe whilst the engine is running, the issue will more than likely be the servo?

Thanks for your help

8 minutes ago, Mattinho18 said:

Yeah you are correct. The valve in the second pic is where it spits to both the servo and the turbo. If that has failed, would it not effect the brakes and the turbo?

I'll try and pry the pipe off, the servo isnt working so can't make it much worse. Just to confirm, if I feel suction from that pipe whilst the engine is running, the issue will more than likely be the servo?

Thanks for your help

Yes, I would expect both brakes and turbo to fail together if it was a problem at the pump end.

And yes, if you can feel good suction from the servo end then that would suggest the servo itself at fault.

I've just pulled the pipe from the servo, minimal if any suction from it. Have ordered a replacement pipe so fingers crossed that does the trick.