Any mechanics in here? Front-wheel drive brake question

Discussion in 'Chit Chat' started by hapaboy, May 4, 2009.

  1. How difficult should it be to rotate the front wheels on a front-wheel drive car when the car is in neutral of course and the front is elevated?

    I have a brake problem with the rear right wheel and just to check the other wheels I jacked each one up. Left-rear wheel rotates freely, but both front wheels are very, very difficult to rotate. They will turn but it takes a lot of effort.

    Two supposedly mechanically-savvy friends of mine have opposite opinions:

    One says that there should be resistance with the front wheels because they are the drive wheels.

    The other says the front wheels should rotate freely without resistance since the car is in neutral; since they don't rotate freely, he thinks there is a frozen caliper issue with the front wheels or that there is something wrong with the brake lines.

    Any mechanics in here knowledgeable about this kind of thing?

  2. Brake calipers can drag a little, but it should not be too difficult to turn the wheel against. If the calipers or master cylinder was stuck I'd think you would have smelled burning brakes by now. If the car is a manual trans, the wheel should turn fairly easily in neutral. If it's an auto, then the wheel will have to turn some trans components with some amount of fluid coupling resistance.

    At least that's the way it worked in cars I've had. It's the reason you shouldn't tow a auto trans car very far, unless you lift the drive wheels or use a dolly/trailer. How hard should it be to turn the front wheels of an auto trans car? Not sure, it's been a while since I messed with one. It also probably depends on the car.
  3. is an auto trans. The more people I talk to, the more the consensus seems to be that it shouldn't be too difficult to turn the front wheels, and for both to be difficult may mean an issue other than calipers or master cylinder.
  4. Hey there,

    Does the car run? Once you get the right rear brake sorted out, you can just drive the car on level ground and then coast and see if you can coast a reasonable distance.

    But I'm speculating that the car you're talking about has been sitting a while. Why? When brake lines get old, the insides of them sometimes break down and collapse like clogged arteries on a truck driver. When that happens, if you press the brake, the master cylinder will push the fluid to the brakes fairly well, but the springs in the brakes won't have enough strength to push the fluid back out. When I help friends in my car club and we come across on old car, we try not to press the brake pedal because it will freeze up the brakes. If it does (for the reason outlined above), the best cure is to just snip the brake line (sever it), so that the arteries are unclogged.

    With my VW bus (yes...its a hobby car), if it sits up for a while, sometimes the brake shoes will freeze to the drum, and I have to rock it back and forth by popping the clutch to break it loose...its usually the brake shoe associated with the emergency brake that freezes.

  5. virtually every automobile made in the last 35 years has disc brakes at the front, and disc brakes have no springs that you speak of. they are self-adjusting and will drag very lightly against the rotor by design.

    if your brakes are dragging excessively, your fuel economy will suffer and the pads life will be shortened. see if these are normal.

    and if you really want to know whether the drag is due to the tranny, just jack up another car and test it out. btw: neutral on an auto does not drag significantly more than neutral on a manual
  6. Being a manual or auto should not matter that much, the tires should still turn easy. What it sounds like is the brakes are dragging or the bearings could be stiff, when was the last time the bearings got greased?
  7. Thanks for all the comments.

    The car has been driven consistently and was not in storage. It only has 40K miles on it even though it's an '01 (Infiniti I35).

    I don't know when it was that the bearings were last greased.

    The problem popped out of nowhere this past Sunday when on a quick trip to the store I heard this loud rubbing sound at low speeds, which got worse when I pressed on the brake.

    Again, thanks for the comments. Trying to get the car fixed ahead of making a move to the mainland and shipping it.

  8. 1.) Your loud rubbing sound is probably just the wear indicator doing its job. It's telling you the brake pads are worn to about 1mm. If both the inner and outer pads have plenty of friction material left, check for a rock or some other debris wedged in between the pad or backing plate (not very common but it does occasionally happen).

    2.) Your Infiniti uses sealed wheel bearings. There is nothing to grease.

    3.) Use a large straight screwdriver to pry the inner pad back. This pushes the caliper piston into the caliper. Are the wheels noticeably easier to turn?

    The tech that told you a little drag is normal because you are turning the drive wheels is correct. It doesn't matter if you're in neutral because the differential, output shaft and some of the clutch packs move with the wheel and axle. (If you put it in park with the front wheels off the ground, you will feel more resistance and the other wheel will spin in the opposite direction because the output shaft is locked and ONLY the differential is moving). Now, "a little drag" is subjective. It's more than a manual trans and less than an automatic in park. Plus some brake drag is considered normal.