Feels like brake drag but mechanics can find no evidence of that

Maintenance/Repairs
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21

You can also use a DVOM to test the condition of the brake fluid.

Tester

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22

Just took a longer drive. Really does feel like my old car (good). Itā€™s quick off the line with < 50% throttle. If I push it a bit I can comfortably skip 4th, etcā€¦ Braking feels better too. I can come to a nice gentle stop now without that little jerk at the end. That was hard to do before, even with careful feathering of the pedal.

So it does seem like it was related to the brakes, except:

  • Guy said the fluid was fine.
  • Hoses didnā€™t need replacing.
  • No evidence of drag on the rotors.
  • No resistance while spinning the wheels (when the car is jacked up).

Is it possible they were dragging a bit, but they just couldnā€™t see it?

23

If the brakes were dragging enough to affect driving performance, the pads would burn up in a few weeks, they would smoke and produce a foul odor.

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24

Sigh. Car was flawless for two weeks and now itā€™s acting up again. Back to dragging an elephant around town. Braking is inconsistent and car wants to dive ever so slightly to the left. Throttle is heavy and requires wide-open-throttle to go from 60kph to 80kph in 5th. Car feels floaty and weird. Vibrations in the steering wheel feel damped.

When the car was working well, a second pump of the brakes while coming to a stop added additional braking power (as youā€™d expect). Doesnā€™t do that now. Pumping doesnā€™t increase the pressure. If I try to stop with just the top travel of the pedal (couple inches down?) Iā€™ll rearend someone.

Rear rotor temps after a short drive (practically the same on both sides):

Outer edge: 90C
Middle: 50-60C
Inside edge: 80C

If I hold the brake pedal as hard as I can at a red light, when I launch, the car feels normal for a bit. Tightens up again by the time Iā€™m up to fifth gear.

Any new theories?

Thanks

25

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That is a ā€œgo awayā€ price. There is no way it should cost that much.

So a brake fluid change fixed it.

Changing a valve cover gasket has NOthing to do with the brakes. Like blaming a haircut for gout.

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26

Yep, fluid change fixed it, but only for two weeksā€¦

27

Take it an independent shop, not the dealer and have them change the brake hoses.

Start with just the rears. Make sure they change hoses, not the metal pipes.

2 Likes
28

Does that car have the parking brake built in to the rear calipers? When changing the pads, you have to screw the piston instead of just pushing it in to reset the parking brake adjustment. If the rubber dust seal on the piston is broken, water can get in to the caliper piston and cause that to become sticky.

Are you able to measure the amount of time it takes reduce speed by a certain amount while coasting? You can test it on the same road while it is happening and then again when it is working better.

Could it be a wheel alignment problem? Not all wheel bearings make noise when they go bad. Could something be shifting in and out of position? Is there unusual wear on any of the tires? Does the steering wheel position for going straight ever change?

29

Use 3rd gear, 5th gear is not for accelerating at low speeds. I take 2nd gear to 80 kph sometimes.

30

For tame city driving, I can smoothly accelerate from 60 to 80 in 6th gear under normal conditions. I do not need to downshift for this type of thing (as Iā€™m having to do now), and I certainly do not have to downshift to 3rd (unless I want to). Itā€™s not a highway/merge situation. Just some roads that slowly transition from 60 to 70 to 80. But thatā€™s just one example. Another: Thereā€™s a hill I need to drive up five days a week, and when the car is performing properly I can easily hold 65kph all the way up using 5th gear. When the car is in itā€™s current state, I need to use 3rd or 4th. I can name a dozen parts of this city where Iā€™m having to use a different gear because of this issue.

I know my car. I know how it is supposed to perform, and Iā€™ve been working it through its gears in this same city, on the same roads, for over six years.

31

One thing you havenā€™t mentioned, when it is normal and you apply the brakes, does it pull to either side at all? When it is acting up and you apply the brakes, does it pull to either side at all?

When it is normal and you are accelerating from a stop, does it pull to either side, even just a little? It may pull slightly to one side due to torque steer, especially if you have a heavy foot. When it is acting up and you are accelerating from a stop, does it pull to one side of the other differently than when it is normal?

BTW, I donā€™t think you need new brake hoses, your vehicle is not that old. But it could if one of the brake hoses had a factory defect to begin with.

The valve cover gasket had nothing to do with the problem.

One more ting. First check your owners manual or maintenance manual for service intervals on the transmission oil and the differential oil, especially the differential oil. Some front wheel drive vehicles with a separate gear oil for the differential require a frequent oil change. Some that share the oil between the transmission and differential use a lower viscosity than in the old days and it needs a more frequent oil change. If you have gone past the due dates on this, not only get it done, but have the shop use a screen to capture any metal particles from the drained oil.

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32

On braking, it seems to dive to the left a small amount.

Itā€™s up to date on maintenance inasmuch as the dealer is not nagging me to do more when I take it in. (that might not be meaningful)

Iā€™m going to take it to the independent shop I used to use before I started playing the dealership game. Weā€™ll see what they say.

Thanks, all

33

If the valve cover leak allowed a substantial amount of aiir into the crankcase, that could cause an engine performance problem. The crankcase is purposely vented by design of course, but the amount of air flow is metered by the pcv valve. An air leak through the valve cover would bypass the pcv valve.

Generally valve cover leaks are pretty apparent by the oil that leaks out and creates smoke when it hits the hot engine parts. But air leaks into the engine are possible. My first car, 62 Ford, made a very loud whistling noise at idle when the engine was warm. So loud that women pedestrians would look around for whoā€™s doing the loud whistling ā€¦ lol ā€¦ That sound was caused by outside air leaking into the crankcase via a valve cover gasket leak.

A really bad valve cover gasket leak could have some effect on braking if it lowered the intake manifold vacuum enough, which would affect the power brake booster performance. Seemsa very unlikely cause to explain OPā€™s symptoms though.

34

I still havenā€™t taken this in to a shop, but I found a fix that seems to be semi-permanent. Iā€™ve only had to do it a couple times over the past month. Braking and acceleration were night and day better after doing it the first time:

  • Hold e-brake handle as high as it can go.
  • Pump the brake pedal repeatedly until it feels like the calipers are solidly against the rotors (7-8 pumps).
  • Release the e-brake handle.

After doing that, the brake pedal has a clean, uniform feel, and I can come to a nice feathered stop. The car accelerates and holds speed with a very small amount of throttle.

I imagine this is either pushing an air bubble out of the way, or itā€™s pushing the fluid past some obstruction in the line itself (or, I donā€™t know, straightening a kink or something). If/when I do take it in, I figure if I tell them this fixes it theyā€™ll be able to pinpoint the issue.

Thanks everyone.

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35

I am a hypochondriac, both with myself and with my car. Sp, I canā€™t trust myself to view symptoms accurately. I always start with the worst-case diagnosis. Two issues come to my mind here:

  1. It still sounds to me that the e-brake system needs closer inspection by a pro.
  2. I not that in your very first post, you discussed brake feel when first pushing the pedal. You have not discussed this for many days. Did the mechanics do anything with the brake booster when they were replacing the gasket?
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  1. Agreed. Thereā€™s something definitely off, but I need to balance time/money against the simple fix I found that is free and works every time.

  2. No, they didnā€™t even inspect the booster, as far as I know. Pedal feel is better after doing my temporary fix.

The fix: Hold e-brake handle as high as it will go, and pump the brake pedal 3-6 times.

I suspect there is indeed a small physical issue in one of the lines, and forcing the fluid to stack in this manor temporary corrects it.

37

Possible, but it wouldnā€™t be my diyā€™er first guess. My guess is there is some brake system component that should be moving freely, but instead is sticking. Unusual failure modes tend occur as vehicles age beyond the 10 year mark. For something mechanical that is sticking, my first guess would be a caliper piston or caliper slide. For a hydraulic problem, my first guess would be a failing rubber brake hose. Pulling on the ebrake temporarily overcomes whatever is sticking & resets the brake components back to their nominal position. But eventually whatever was causing them to stick will cause them to stick again.

As far as you know has anyone clamped the rubber brake hoses during a brake system diagnostic? Itā€™s an effective way to isolate the system, but sometimes that will damage the rubber hoses.

38

Just a couple comments. I would focus
on the parking brake issue. On my Buick. If someone would bump the e brake pedal, I would have to grab the cable under the car and pull on it to re set it . Sure, sticking cable that I never bothered to investigate. So check for a worn or sticking cable and the return springs work.

If the e brake uses the same discs as the regular brakes and not a separate drum, check for a build up of grease and junk on the slides on the caliper. Where the disks slide on the caliper. If they greased them to make them slide easily, crud can collect on them gumming up the sliding of the disks in and out. I only grease the pins, not the slides. See rainmanray you tube if you want for a picture.