Hybrid rear brake wear

[heathholley]

Hi everyone,

So I'm curious about something and was hoping for another person's opinion. I recently took my 2007 TCH in for it's 50k mile service. I purchased the car March 19, 2006 brand new. Since then, I have (religiously) taken my car to the dealer for every 5k mile service. Last week, my dealer informed me that the rear brake pads were down to 2mm and needed to be replaced. Curious about my brake pad usage over the past 50k miles, I pulled out my service receipts which list the thickness at each inspection.

I plugged the data into a spreadsheet and used it to create the graph below.

So, my question is this. Why isn't my brake wear (for front and back) in a straight linear motion downward? For example, how did I go from 7mm to 2mm in 5000 miles?? Or better yet, how did I go from 5.5mm to 8mm in 5000 miles? Are these magic Toyota brake pads that sometimes regenerate themselves?

Please, someone, enlighten me.

[njerald]

There are 4 pads/axle.

They could be measuring different pads, measuring them wrong or lazy and just guessing.

Nothing tough about that.............

[heathholley]

True. I suppose I expected a more accurate inspection from the dealership. If they are in fact lazy/guessing or just wrong, maybe I should just take it to Jiffy Lube (or the like) for service instead.

[jim2527]

Heat will expand the pads...they 'grow'. If they're measure while hot they can be a different size. I think wear is exponential, as they wear there's less material to dissipate heat, less heat disspipation leads to an increase in wear.

An ohhhh.....the mechanic was probably saying, "WTF, is this guy insane" and eyeballed the measurement.

[acarapella]

Remeber... The TCH uses the drivetrain for breaking upfront, saving the pads. The car is not awd, thus the rear wheels need to use the breaks... So they wear faster. Same thing with mine. Replaced all the way around at 59,000 miles

[ukrkoz]

every front wheel drive car brakes down more with front wheel brakes. period, end of sentence. no matter how well proportionate valve is working, it's the weight distribution.
i have replaced dozens of brake pads, on various domestics and imports, and front always needs to be replaced first, waaaaaay ahead of rear.
btw, i have just checked mine today, same model. they are only 1/4 worn out. 52 000 miles. wear is more or less equal per rotor sides, but caliper guides already lost lubricant on them and were not sliding well. fixed that.

as of all those measurements - looks like quite a yarn your dealer is weaving for you. bs, otherwise.

[Duramax2002]

My 2007 hybrid has over 140k miles changed rear pads first at 86k. The front pads were not changed until almost 100k. Have changed the rear again since and not the front. The back wear almost 2 to 1. I know this goes against normal convention???

[Frodo65]

Originally Posted by ukrkoz

every front wheel drive car brakes down more with front wheel brakes. period, end of sentence. no matter how well proportionate valve is working, it's the weight distribution.
i have replaced dozens of brake pads, on various domestics and imports, and front always needs to be replaced first, waaaaaay ahead of rear.
btw, i have just checked mine today, same model. they are only 1/4 worn out. 52 000 miles. wear is more or less equal per rotor sides, but caliper guides already lost lubricant on them and were not sliding well. fixed that.

as of all those measurements - looks like quite a yarn your dealer is weaving for you. bs, otherwise.

The TCH is different in that regard. For light braking, the fronts don't get much use; it's the rears + the MG 1 / MG2 spooling up. Only if you REALLY stomp on the brakes (or below 5 MPH or so) that the fronts get a workout. A IR thermometer will confirm - it's the first FWD car where the rear brakes have higher running temps than fronts.