Is This Right?

[KS GTI]

I had my R in for annual service today and the back brake pad thickness was reported as 4mm. The service advisor recommended I keep an eye on them for possible future replacement. The car only has 32k miles and i was surprised the back pads were wearing. The fronts were 8mm.

Then, I was told that VW's priortize the back brakes in everyday use. That's contrary to everything I thought I knew about car braking.

The service advisor said that's why VW's 'squat' under braking unlike other cars that 'nose dive'.

Can this be right?

Thanks, Bob.

 

[iceorbital]

back breaks get used often to counter under steer

 

[SRGTD]

@KS GTI - If your car has ACC I believe the car uses the rear brakes more than the front brakes to help maintain the speed you’ve set - e.g. to slow the car down when travelling downhill and when you begin to catch up slower moving traffic in front of you.

In the UK, VW dealers are always trying to upsell new brake pads and discs and there are probably instances where the actual disc thickness is greater than the reported thickness. If dealers in the US adopt this same approach, you might want to either check the disc thickness yourself, or find a trusted independent to check them for you.

 

[starsmith]

The service advisor said that's why VW's 'squat' under braking unlike other cars that 'nose dive'.

That is absolutely wrong and physically impossible.

 

[bentin]

That is absolutely wrong and physically impossible.

Not in reverse. Maybe the mechanic just had the car backwards on the lift?

In all seriousness, do you do a lot of city driving? I needed new front and rear brakes at 40k miles, so I just traded it in before the light came on. Don't the backs have a brake sensor too? I'd wait for that to come on before changing pads/rotors.

 

[DarkArrow]

The service advisor said that's why VW's 'squat' under braking unlike other cars that 'nose dive'.

Lol, VWs are now so advanced they brake the laws of physics. You should ask the advisor if the car nose dives when accelerating, he might be confused on the which side the front of the car is.

To answer your question, though, the XDS system can cause accelerated wear of the rear brakes. I was amazed my rear pads were toast at 17k miles (including multiple track days). If you're driving spirited, it's possible your XDS is killing your rear pads. So, yes, your rear pads can be wearing faster than your fronts, but no not because of what the service advisor is stating.

To address what bentin said about sensors, AFAIK, the only pad that has a wear sensor is the front right inner pad (NAR model, not sure about ROW since the brake system is different, including a different brake reservoir location). Do NOT wait for the brake wear sensor to illuminate to begin considering a pad change.

 

[bentin]

Thanks, couldn't remember. BMW's had the driver front and pax rear for sensors, I'd never really thought to check what VW was up to.

 

[HalfGerman]

On my old '04 Passat braking was rear biased. When through 2 sets of rear pads vs one set for the fronts in the same time frame.

 

[starsmith]

Front and rear pads are different and will wear at different rates in general. Doesn't necessarily tell you how much braking each end is doing.

 

[BIGTom]

Yes it seems so. I have 34k on my R, same pad thickness in the front and back as you have.

 

[scrllock]

these cars are heavily front-biased for braking. rears will wear pretty slowly unless you're using XDS a bunch.

 

[JC_451]

Sounds like they want to sell you rear brakes.

And the service adviser didn't know enough about the car to give you the XDS wearing the rear pads excuse. I'm sure that is true that XDS uses your rear pads more but it shouldn't make them wear faster than the front.

The fronts are still doing most of the braking most of the time.

 

[hans611]

GTIs have XDS, but Golf Rs have "XDS+", from what I understand, only 4motion cars have it work on the rear wheels too, hence the extra rear pad wear seems to be a Golf R thing...?

XDS electronic differential lock is an extension of the familiar EDL function. However, XDS responds not to loss of traction but to the unloading of the front wheel on the inside of the corner when cornering fast. XDS applies pressure from the ESC hydraulics to the inside wheel to prevent it from spinning. This improves traction and reduces the tendency to understeer. The level of pressure applied ranges from approximately 5 to 15 bar. The impression when driving is similar to that of a limited-slip differential in toned-down form. The precise, one-sided build-up of brake pressure makes cornering even sportier, quicker and more accurate.

(Written for the FWD Golfs, the same is true for the 4Motion XDS+, but for all four corners.)

I have been reading for years since the MK5 days that "VW uses softer rear pad material" supposedly to prevent noisy rear brakes, due to the less braking they do.... Maybe its a combination on things?

My MK5's rear pads actually did wear well before the fronts....My current car has 52k mi, on the original brakes, and they are at 7mm and the rears at 4mm (like OP)...

So it seems my rears are definitely wearing faster as well...

I don’t think you will need to change them at 4mm though, I estimate they still have 1/3 to go at least…

 

[scrllock]

GTIs have XDS, but Golf Rs have "XDS+", from what I understand, only 4motion cars have it work on the rear wheels too, hence the extra rear pad wear seems to be a Golf R thing...?



I have been reading for years since the MK5 days that "VW uses softer rear pad material" supposedly to prevent noisy rear brakes, due to the less braking they do.... Maybe its a combination on things?

My MK5's rear pads actually did wear well before the fronts....My current car has 52k mi, on the original brakes, and they are at 7mm and the rears at 4mm (like OP)...

So it seems my rears are definitely wearing faster as well...

I don’t think you will need to change them at 4mm though, I estimate they still have 1/3 to go at least…

AFAIK it's just a coding change. My experience is that the rears wear pretty slowly with XDS on weak/off.

 

[iceorbital]

XDS Differential Lock Adjustment

XDS is an electronic differential lock, and lets you grip the road when cornering fast. It improves responses to ensure an even safer drive. In moments of fast cornering XDS lightly brakes the inside wheel to prevent wheel spinning. The result is better traction and a reduction of any tendency to under steer. This tweak will vary the aggressiveness of XDS.

Select Control unit 03 (ABS)

Security code 20103
Adaptation
Select: Expanded Electronic Differential Lock
Options: Weak – Normal – Hard