front brake pads -are they supposed to rub against the discs

[fishtank Junior Member Find all posts View Profile Close fishtank]

Ptado has developed a scraping noise coming from the front left brake pads. Took wheel off and when car is in nuetral its a little difficult to turn the wheel manually using my hands. Sounds like something like sand is stuck in there. Recently got back from Fraser so that would make sense. However. Took the front right wheel off and it too isn't easy to rotate with my hands. It doesn't make the scraping metal on metal sound but it seems like the pads are rubbing against the disc also.

Is this normal or do they need calibrating somehow? I Am also having issues with poor fuel economy so wondering if this might be contributing to that issue.

Or are my discs buggered and need replacing lol?

Thanks!

[Early Member Find all posts View Profile Close Early]

Have you checked for any sand between brake pad and pistons?

link below might help with checking the brake calipers:
http://www.pradopoint.com/showthread...t=brake+change

[Walky88 Member Find all posts View Profile Close Walky88]

Have you checked to make sure your pads aren't worn out and its the scraper hitting??

[fishtank Junior Member Find all posts View Profile Close fishtank]

Hi yes I checked them last night and it seems the inner left pad is worn right down. That explains the scraping noise.

However I was still curious as to if its normal or not that the pads are constantly in contact with the disc?? Seems all 4 front brake pads are rubbing against the discs at all times. When car was jacked up off the ground I found it hard to rotate them freely. Is this normal or is there a way to calibrate them? Seems as though this would affect fuel economy having the brakes rubbing the discs all the time. And yes I had the transmission in neutral. Lol

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

It's normal for the pads to touch the rotors a *little* as there isn't really anything to pull them back apart from friction. However, it should be quite easy to rotate the tyres by hand. I would suspect your brake calipers require overhaul as it's common over the years for dirt/grime to build up and make them stick. You may even find the piston seals are broken, dirt/grim has entered the caliper and seized the pistons.

Overhaul kits are very cheap from auto parts stores, but it's a messy job, and if you don't know what your doing the results may be dangerous. Safe option is to pay a brake SPECIALIST but it will cost around $1000 total (4 calipers).

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

Yes. When you pull up and turn the car off your foot is on the brake and holding it there. Obviously that pressure is gone when you take your foot off but the pads can still be touching slightly to put just a little bit of resistance against the rotor... also, don't forget that given these vehicles don't have locking hubs, when turning the rotor, you're also turning the driveshaft and diff gears.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

The way they actually work is when you press the pedal the pads are pressed against
the disc, this movement distorts the "O" ring brake fluid seals on the pistons, when you release
the brake pedal the "O" rings pull the piston back a little. In a perfect setup, there should be
little drag between the disc and the pad unless the disc is warped etc.

If one pad is wearing I would be checking that it has been installed properly and that the piston
is not binding. Another thing to check is that the piston or caliber bore is not rusted and pitted
as this will cause them to bind.

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

^^^^+1

It's very common to see the o ring distorted when the piston is not pushed back in correctly during the last change.

[MidLifeCrisis Out of control poster! Find all posts View Profile Close MidLifeCrisis]

I thought this was an April Fools post until I read the detail.......

[Anth120playdo Banned Find all posts View Profile Close Anth120playdo]

Sometimes when butchers change pads the damage the dust boot.
Dirt & crap gets in & causes some tightness of the piston.
Genuine boot kits are cheap.
Overhaul if you have a tight piston.

[fishtank Junior Member Find all posts View Profile Close fishtank]

Changed pads as they were low and the metal scraping sound was the low pad indicator. Now with new pads it still makes a scraping sound. Only on the left and only once a rotation which leads me to believe the rotor is warped.

[Walky88 Member Find all posts View Profile Close Walky88]

Changed pads as they were low and the metal scraping sound was the low pad indicator. Now with new pads it still makes a scraping sound. Only on the left and only once a rotation which leads me to believe the rotor is warped.

Yes very possible.

[Ken in Cairns Junior Member Find all posts View Profile Close Ken in Cairns]

Get the callipers done and get the disc's machined. Piece of mind that everything is OK.
You can get aftermarket discs with either water channels or drilled ones, as mine were OK to machine I just did that.

When my master cylinder went not long after I bought mine, the brake guys said that this model Prado had a habit of not letting the front callipers release properly due to the way the ports in the master are configured, and he gives these front ports a little more countersinking to increase the port radius. Not sure if this is information is correct or not, but I haven't had any problems with front brake drag since the master was replaced.
And since I redid all the callipers and load sensor the difference in my brakes is amazing.
Well worth the time and trouble.