Screeching Wheels - Bad MPG

[feroz28]

Just purchased a 51 plate tdi sport estate with 100k miles on the clock. The car has been okay for the last week but am now getting schreeching noises from the front left at the same time getting only 30-35 mpg.

The screeching is like a metal to metal sound but only occurs after about 5 miles on motorway and therefore am assuming something getting hot then screeching.
:confused:

[angus]

Initially sounds like a brake is seized on and you`ve run out of pads.

[feroz28]

Replaced rear pads and disks with originals. checked the front pads and disks and they look pretty new. Not originals though. Does this have a bearing?

[Stevebt]

Hi

With all the salt on the roads it could be a siezed sliding calliper, have you noticed is there a build of heat coming from the front wheels after it happens?

[jamoca]

I had the same problem on the drivers' side. It turned out to be that the metal plate on the inner side of the brake disc was rubbing against the brake disc as the wheel rotated. Extremely loud screeching.

If this is the problem, chances are the bolt that secures this plate in place is either loose or has dropped off. It's a very easy fix for an extremely annoying problem.

Hope that helps.

[feroz28]

I've jet washed the brakes when cold and am worried about these brake plates. May need to invest in a trolley jack. I've read on other forums that there are these pins in the calipers. Do these pins rotate or touch the brake disks?

[Stevebt]

Hi
The sliding or floating caliper has 2 pads but only 1 piston. The caliper is mounted on pins or bushes that let it move from side to side.
When the brakes are applied, hydraulic pressure forces the piston inwards. This pushes the pad against the disc. The caliper is free to move on slides, so there is a clamping effect between the inner and outer pads. Equal force is then applied to both pads which clamp against the disc.
http://www.innerauto.com/store/images/prodimage/images/WORLDPAC/generic_ace_597.jpg

As opposed to the two piston type, shown below.

http://moodle.student.cnwl.ac.uk/moodledata_shared/CDX%20eTextbook/dswmedia/images/350px-Bcallipers_01m.jpg

[feroz28]

I've checked the wheels after a drive and have found the front passenger wheel is extremely hot compared to the other wheels. Looks like a siezed caliper looking at the above advice. Can i recover it?

[onzarob]

I've just replaced my calliper because of the same reason, cost £75 for a recon unit. there are two type used ate or Lucas.

Get a Haynes manual and follow the instruction its a straight forward job. just make sure you've got the right tools, IE jack axle stand, brake bleed kit, 7mm hex key and bleed spanner. :D

I would like to add if you've not done brakes before, either get someone who has to help or pay a mechanic as it your neck if you get it wrong;)

[feroz28]

I went out to the local hardware store to get a 7mm hex but believe or not all the sets had all sizes except size 9mm and 7mm. is the car specialist thing?

Where's the port to connect a vag-com to in a passat. will this show any readings?

[onzarob]

Yes 7mm hex seems to be the standard for brakes;) get a socket type as they can be tight.

the ODB2 socket is under the coin tray next to the handbrake ;)

[feroz28]

You're the man!!

I'm gonna have to pick your brains around pressure and vacuum hoses next. Got a picture?

[onzarob]

You're the man!!

I'm gonna have to pick your brains around pressure and vacuum hoses next. Got a picture?

Not sure what you mean, inrespect of the caliper or a different fault?

[dirtyderv]

I doutbt VAG COM will bring anything up. I know for my old 306 you could get a recondition kit for the caliper, new seals etc as these are distroyed when the caliper heats up. Probably a cheaper way of doing it. Although my caliper was <knackered> and had to fork out &#163;100 for a new one (and it was a back one too!)

[Stevebt]

Hi

I would get the wheel off and see if you can free the caliper up before laying out any money, you would be suprised what a good cleen up and some Copper Slip Greese can do.