V70: Wheels/Brakes rear brake ventilated or plain ?

[griston64]

Originally Posted by ferdinotch

HI guys,

V70 D5 2012 215HP with autogearbox.

I'm having trouble with too much dust on my rear brake compared to the front (like twice as much).

I figured out that the pads are specific if you have ventilated or plain discs at the rear.

So I ordered the right pads for my setup : plain discs, i did not change the pads yet.

I browsed my VIDA, connected to my car, and in the specification, it says that my car is coming out of the factory with ventilated discs.

I had plain discs when I bought it, and that's what I have right now.

Does anyone know better about this ?

I'm gonna check the caliper setup to see if it matches with the ventilated discs requirement.

I have the identical car to you and get hardly any brake dust on my rear wheels ? original discs and pads from new as well

[apersson850]

From what I've been told AWD cars have ventilated discs rear too.

We had a similar issue, where one of our XC70 got very dirty at the rear, but not the other. I figured out what the issue was with our car.

The rear pads are mounted with tabs sitting in slots in metallic springs. These springs are in turn pushed into slots in the caliper. The caliper tends to rust in the slots. This makes the slots narrower, which in turn bends the spring when it's pushed down into the slots. Thus the slots in the spring become too narrow, and limits the movement of the pads when they are in position. Not so much that you don't get a good braking effect, but enough to prevent the pads from releasing properly. Hence you get a lot of brake dust.

By grinding off the rust in the slots in the caliper, the springs fitted nicely and the pads were sitting good enough to avoid rattling and screaming, but loose enough to allow them to retract.
No more excessive dust in the rim.

[ferdinotch]

thank you for the tip. My wheels are totally free at the back, but i will check.

[apersson850]

As our cars are both AWD, there's always some resistance when you rotate a rear wheel by hand. It's difficult to tell if that's from the clutch in the Haldex unit or the brake or both.

[ferdinotch]

Hi apersson850, my car is a FWD so it's easy to see if the rear wheels are free or no.