Brakes Sensor/Replace Q's?

[mcomet]

Hi,
I am starting to think about some DIY stuff for my box. I haven't yet done anything, don't yet own a jack or jack stands... I am planning on a front bumper removal and radiator washing this weekend. That will be my first semi realjob.

Anyhow knowing my front brakes are around 35% right now... I am considering doing a brake pad replace in the future ... My Q's are...

1. For the standard S brakes I have, how do I determine if rotors also need to be replaced? What is the thickness to check for?

2. I had new brake fluid and a flush done a few months ago by dealer... so I assume that is good.. Dealer told me maybe does that every year or two... How often do people here do it?

3. Biggest curiosity...dealer told me save $ and wait for the pad sensor light to turn on... which apparently triggers at around 15-20% aka 1.5-2mm It sounds like a lot of people change earlier.. when do people usually change pads?

4. bonus Q... any recs on a jack and jack stands? I don't want to break the bank...I am fine with something decent but safe... Just pick one up at a local auto store or such?

thanks,
comet

[Mark_T]

1. replace when the edge lip is about 1mm
2. brake/clutch fluid change every two years
3. no harm in that - why replace sooner than necessary?
4. as long as they are rated for your vehicle weight, are good quality, and will give you about 17" of lift, go for it. I have a set of combination bottle jack/jack stands and I love them. Less lifting with the floor jack.

[Dave928]

1. 1mm lip is nothing, you can go beyond that.
2. 2 years
3. when i was a VW Dealer tech, i would recommend replacement if the pad material was thinner than the backing plate it's glued to
(~3-4mm). the thinner your pads, the quicker they heat up/overheat.
4. 2 pairs of the 6 Ton Stands and a floor jack from O'Reilly's. you have 3 in concord.

[opus69]

I just replaced pads at 43,000 on a 2002 S. The front pads were into the sensor area (sensors were fine so I did not replace them). Rotors had a lip between .5 and 1.0 mm. If it had been any of my other vehicles I would not have changed rotors. As I have commented on other posts, the two most important things for me with any car are tires and brakes. With a high performance auto I also want maximum stopping ability. It is an easy DIY project. When looking for a jack keep in mind low profile and long reach. I prefer the pin and post type jack stands but keep in mind if you jack up only the rear the front will go rolling (use chocks). Jacking up all four corners gives a much more stable platform. As a final safety measure I always put one of the wheels under the car in case of catastrophic failure.

[Mark_T]

Originally Posted by Dave928

1. 1mm lip is nothing, you can go beyond that.

The 1mm figure is a rule of thumb derived as follows (from the factory and the Bentley service manuals):

For the base model, front new thickness is 24mm, min thickness 22mm and for the rear it is 20mm new and 18mm min.

For the S model, front new thickness is 28mm, min thickness 26mm and for the rear it is 24mm new and 22mm min.

Therefore, regardless of the model, max wear is 2mm overall, or a 1mm lip on each side of the rotor.

This 1mm number is also stated as a replacement indicator on Pedro's site in the brake DIY section.

Or you can go with the advice of some guy on the internet telling you to disregard factory specs and established experts (Pedro) and "go beyond that". I wonder how far "beyond that" you can safely go? Well, one way to find out I guess....

Originally Posted by Dave928

3. when i was a VW Dealer tech, i would recommend replacement if the pad material was thinner than the backing plate it's glued to
(~3-4mm).

FYI, factory specs for brake pad min. thickness is 2.5mm with sensors and 2.0mm without. Interesting to recommend premature replacement for the pads while suggesting that rotors be pushed beyond their service limits.

Also, not sure why you would want four 6000 jack stands for a 3000lb car. Seems to be a bit of overkill, not that there is anything wrong with that, but a set of 3000 lb stands is more than adequate,and much less expensive.