All,


I'm finding my brake pedal is very stiff after a cold soak (8 hours overnight or at work, for example). Since I've a Lariat Ultimate with the pushbutton start, I need to press the brake while starting, so it's noticeable each time.


I thought I read here or elsewhere that this could be a sign of a vacuum leak once the truck is shut down.


Just checking to see if others experience the same? Truck has 370 miles and it doesn't seem to be causing any issues running, and doesn't present any issues with starting. Want to see if this is something to put on my list of things to check at first service, or if it might be somewhat normal.


Thanks!

 

Any thing that you have a question about on a new vehicle should be brought to the dealers attention on the first service. That way if something develops later, even if they say it's normal, you have a written documentation stating your concerns. Make sure that they state it on the work order.

 

Understood and will do. Trying to gauge if this might be normal, though.
Thanks.

 

It's not normal for my truck. My break pedal feels the same if the truck is running or not.

 

As I PM'd you, it's not normal. Most trucks don't do it. Some do it sporadically like mine. Some do it every time since new like Epic's. It's likely the master cylinder vacuum check valve.

 

Mine does it but it doesn't affect anything. Brakes work fine, feel fine, sound fine. I have it on a warranty list also and won't take it to the dealer until 30,000 miles or so.

 

Mine did it a couple times when I first got it, but I haven't seen it in months. Maybe it corrected itself.

 

It has happened a few times on mine and I have over 5500 miles. I will bring it up to the dealer who won't be able to replicate it and nothing will get corrected/fixed but I will have it documented.

 

If enough people complain about this, there will be a procedure in the future to test and correct.

 

Has anyone who was experiencing this taken their truck in for it yet? This is the only issue I've had in 3K miles and I'm not sure I want to leave the truck with the dealer yet if the likelihood of them fixing it is low. Just curious if others have gotten it figured out. Thanks.

 

Yes, mine has been in a few times for it. After telling me over and over that it was normal, I finally got more aggressive with them. They contacted their tech hotline and Ford told them to replace the vacuum booster on master cylinder and the vacuum hose kit. Both were, of course, on national backorder. They finally got the hose kit two weeks ago which was installed and did nothing. The service manager told me yesterday that the booster will be in later this week so hopefully that gets installed soon and cures the issue. I'll report back either way. Make sure you push the issue mooch. The more people that complain, the more likely there will be a definite cure in the pipeline for other owners...

 

Isn't the pump not engaged resulting in no hydalic break assist until the truck is started? Or am I missing the point.

 

There is a check valve meant to keep the vacuum in the master cylinder booster when the truck is shut down. This is why after shutting the truck off, if you pump the brakes, you will get one or two easy pumps before the pedal goes stiff. The vacuum is stored there until it is used up. Now, with the new trucks requiring you to depress the brake pedal before they can be started, you want that pedal to be soft. For some of us, the check valve isn't holding the vacuum in the booster making for a VERY hard pedal at start up. Often I get the error in the dash telling me I must depress the brake pedal for the truck to be allowed to start. Well, I was but I didn't go gorilla stone on it and it didn't go down far enough. Most folks don't have this issue but there have been a couple threads on it here so it's not completely uncommon either.

 

I will, just waiting for some additional reasons to visit the dealer. I'd rather not leave the truck for a day only to have the same experience as you. This is the only issue I've experienced so far.


Please keep us posted on your results. Do you know which hoses were replaced? The ones that come right off the booster and meet at the manifold behind the coolant reservoir? I was trying to determine if the check valve is within this hose or a part of the booster. I actually think it may be within the hose.


Thanks.

 

Brake booster changed under warranty yesterday. It had increased frequency to the point where it would happen every time the truck was shut down for 15 minutes or more. So far, the issue has been resolved...