More brake dust on rear wheels than the front wheels

brownnugen

Veteran Member
Joined
Jan 18, 2001
Location
Charleston, SC
TDI
2015 GSW TDI, 2011 JSW TDI & 2018 Atlas 2.0T S
What is the best way to determine whether the brakes are dragging or not?

There is a noticeable difference in the amount of brake dust that is covering both rear wheels compared to the front. At first I thought the brakes may be dragging and could be the reason I am only getting about 35 mpg on this manual BRM. But when I noticed this on both rear wheels, I starting thinking that maybe the previous owner used a different brand/material of brake pads on the rear versus front. Visually and by feel, the rotors are smooth and no signs of uneven wear. When I took off the wheels to take a look at how much pads were left, it didn't look unusual either.
 

sptsailing

Veteran Member
Joined
Jul 9, 2010
Location
Safety Harbor, FL
TDI
2006 Jetta Manual, stock with Panzer Plate & Franko6 modified EGR cooler & CAM
VW has arranged the brakes such that the back brakes do most of the work, unlike the standard practice of many other brands of cars. As a result, the back brakes wear out faster, which could account for the greater display of dust.

If the brakes are dragging, the disks will be hot after driving awhile. Use primarily engine braking to stop, then get out and check if the disks are hot.

If you are getting poor mileage, I now believe the first suspect should usually be the camshaft.
 

brownnugen

Veteran Member
Joined
Jan 18, 2001
Location
Charleston, SC
TDI
2015 GSW TDI, 2011 JSW TDI & 2018 Atlas 2.0T S
VW has arranged the brakes such that the back brakes do most of the work, unlike the standard practice of many other brands of cars. As a result, the back brakes wear out faster, which could account for the greater display of dust.

If the brakes are dragging, the disks will be hot after driving awhile. Use primarily engine braking to stop, then get out and check if the disks are hot.

If you are getting poor mileage, I now believe the first suspect should usually be the camshaft.
The camshaft and timing belt was replaced about 20,000 miles ago at a reputable shop before I owned the car, so I am hoping that is not my problem.

Would a quarter mile easy (15 mph) drive through my neighborhood be long enough to test if the rear brakes are dragging?
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....
Just inspect the rear brakes. Make sure the parking brake cables are free, which is a common failure item (although not as frequent on the A5s as on the A4s, but they still can fail). And that the parking brake levers on the calipers return to their rest position against the stop.

Then if you like, you can also take the calipers loose and make sure that all the slides move freely and that the pads are not pinched in their perches, which is also common.

Rear brakes wear faster than the fronts, lots of modern cars are like that.
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2007 Seat Alhambra 2L tdi
Rears get more use with gentle braking so I think you need to drive faster and brake harder to balance things out lol

Seriously though, it's designed under gentle braking to use the rears more to stop the nose dive and keep things smoother. At least that's what I've read.
 
Top