Braking sensation when coasting

[cls1989]

2019 transit connect XLT 2.0L about 35k miles.

If I’m driving about 50 mph and I let off the gas to coast, the car feels like its braking and starts to lose speed very quickly. It’s done this a couple of times. Is this normal? If not what could cause this? I’m driving on a flat terrain. No slope / hill.

More information, I recently changed pads and rotors, and the rear driver side pads were worn to nothing and the rotors were rusted see photos. I thought maybe this could have been caused by a seized caliper. However, when I turned the piston back to its home position during the change it turned without much effort. Also I checked by spinning the wheels a week after changing the brakes, and the wheels spin without any trouble.

Looking for advice on how to troubleshoot this. Could I be wrong and the caliper could be seized? If yes what additional checks can I do to prove this? If it’s something else how do check for that? Thanks

 

[atikovi]

Restricted brake hose?

 

[bullwinkle]

Do any wheels heat up excessively when driving long distances on a highway? That’s the easiest way to test for a stuck caliper.

 

[Ursatdx]

Infrared thermometer.
Check temps on each wheel after driving.

 

[cls1989]

Infrared thermometer.
Check temps on each wheel after driving.

I was thinking about purchasing an infrared thermometer to do this check. Any cheap thermometer on Amazon should work for this test, or do I need something expensive?

 

[D60]

I was thinking about purchasing an infrared thermometer to do this check. Any cheap thermometer on Amazon should work for this test, or do I need something expensive?

I think even the basic ones are accurate enough

 

[RhondaHonda]

You can probably use your hand and feel if one is overly hot after a drive.

 

[demarpaint]

Those brakes are shot and probably hanging up, just look at the difference of wear between the inner and outer pads. My guess is the hose/hoses are shot, broke down internally and ruined a caliper or more. Check the temperature of the calipers and rotors after some stop and go driving and proceed from there. From the looks of the pictures you should be able to tell where the problem is just by touch.

 

[John105]

I did have a faulty brake hose on my Maxima when it was about 18 years old--fluid went to the caliper, and couldn't come back, so my right front brake was dragging and got worse and worse to the point of smoking. But, the pads were not uneven like that. The web explained it to me that inside the hose, the rubber deteriorated creating one way flow. Because I had already replaced the caliper and exact same result.

Funny I just junked the car--the caliper was a Raybestos coated one and it looked brand new after 7 years, whereas the other 4 being 25 y.o. were all dark and rusty.

 

[D60]

Also, are you getting any lights or codes?

Yaw control/steering angle will cause the vehicle to engage a single caliper/brake, and sometimes on SuperDutys at least trailer anti-sway (which is automatically enabled with each start) will cause the rear brakes to do weird things (the latter is not likely applicable here but the point is to consider things that may cause the vehicle to be "helpful" with increasing intrusion of "driver assistance" features)

 

[Number_35]

If this started after you did the brake work, check to sure you didn't twist one of the hoses 360° when reinstalling the caliper.

Ask me how I know. (Blush!)

 

[IndyIan]

I was thinking about purchasing an infrared thermometer to do this check. Any cheap thermometer on Amazon should work for this test, or do I need something expensive?

Your hand is good enough, I had a sticking caliper on the focus as the pins had gotten rusty so the one brake was dragging. I just got a new caliper on that side and some new pads for both sides and motored on.

 

[cls1989]

If this started after you did the brake work, check to sure you didn't twist one of the hoses 360° when reinstalling the caliper.

Ask me how I know. (Blush!)

It was doing this before the brake change

 

[cls1989]

Also, are you getting any lights or codes?

Yaw control/steering angle will cause the vehicle to engage a single caliper/brake, and sometimes on SuperDutys at least trailer anti-sway (which is automatically enabled with each start) will cause the rear brakes to do weird things (the latter is not likely applicable here but the point is to consider things that may cause the vehicle to be "helpful" with increasing intrusion of "driver assistance" features)

It’s only happened when wife has been driving so not sure on the codes. I have a scanner. Would there a record of the codes if I checked with the scanner?

 

[JohnnyG]

In the old pics, it's pretty clear that the caliper was frozen in place, not sliding on the pins.
Piston might be stuck too. (now)

 

[cls1989]

Also, are you getting any lights or codes?

Yaw control/steering angle will cause the vehicle to engage a single caliper/brake, and sometimes on SuperDutys at least trailer anti-sway (which is automatically enabled with each start) will cause the rear brakes to do weird things (the latter is not likely applicable here but the point is to consider things that may cause the vehicle to be "helpful" with increasing intrusion of "driver assistance" features)

I drove it today and it did it multiple times and no light / codes. Just checking by hand the rear driver side wheel does feel hotter than rear passenger side.

 

[cls1989]

I just jacked up the car and was able to turn both back wheels without any issues. They spin freely. I ordered an infrared thermometer and should be able to measure temperature for each wheel tomorrow. Thing is if the rear caliper was sticking I'm assuming I wouldn’t be able to turn the wheels freely?

 

[cls1989]

I also came across something called Active Deceleration Fuel Shutoff which sounds like what’s happening. Below is a description I found online. How do I confirm whether or not my Transit Connect has this feature?

 

[Dave9]

I read this topic earlier and in the back of my mind, I was wondering if you were just unfamiliar with modern fuel cutoff strategies and also, that modern Fords use a BMS battery charging strategy that (unless the battery charge state is low) only energizes the alternator during deceleration events to improve fuel economy.

Depends on how much deceleration there is. You definitely can't compare older vehicles without these techs, to newer ones that try to conserve energy and charge the battery the most, the moment you left off the throttle... which is no longer even a true throttle, just a command to the computer on what to do.

The question is, what led to the prior uneven brake wear and was that corrected? It was uneven before and now you reported it seems hotter on left rear.

The caliper does not seem to be seized out if you can freely rotate the wheel, but do, do this test after applying (and then letting off...) the brakes as well.

When you changed the pads and rotors, was that all you did, or did you do a full service brake job which includes derusting the caliper slide rails, checking for clearance (vs binding) of the pad ears/travel, and make sure the slide pins were free of corrosion and adequately lubed? I'm just spitballing at this point.

 

[cls1989]

I read this topic earlier and in the back of my mind, I was wondering if you were just unfamiliar with modern fuel cutoff strategies and also, that modern Fords use a BMS battery charging strategy that (unless the battery charge state is low) only energizes the alternator during deceleration events to improve fuel economy.

Depends on how much deceleration there is. You definitely can't compare older vehicles without these techs, to newer ones that try to conserve energy and charge the battery the most, the moment you left off the throttle... which is no longer even a true throttle, just a command to the computer on what to do.

The question is, what led to the prior uneven brake wear and was that corrected? It was uneven before and now you reported it seems hotter on left rear.

The caliper does not seem to be seized out if you can freely rotate the wheel, but do, do this test after applying (and then letting off...) the brakes as well.

When you changed the pads and rotors, was that all you did, or did you do a full service brake job which includes derusting the caliper slide rails, checking for clearance (vs binding) of the pad ears/travel, and make sure the slide pins were free of corrosion and adequately lubed? I'm just spitballing at this point.

Yes when I change the pads and rotors I wire brushed and greased the guide pins. I also did check the fit of the new pads on the bracket and there weren’t any issues there. I even derusted the area on the bracket that the pad ears rest on.