#brakes

John writes:

Hi Sajeev,

I’ve had a 2009 Dodge Caliber SRT4 for a few years and it’s coming up to its first all-around brake job at 50,000 miles / 80,000 km (I drive like a granny). I work at a dealership (different brand) but can get parts at a bit of a discount. Still, OEM brakes + pads on this thing are $980+tax Canadian. From what I’ve seen I can get aftermarket ones for a quarter of that. One of the mechanics here suggests I put on OEM pads and aftermarket discs.

Mike writes:

Dear Sajeev,

I have been a fan of TTAC for a while now. I am motivated to write by the recent responses to towing with a 2005 Odyssey. Two years ago I bought a 2008 Toyota Sienna and a 21 foot (actual total length) travel trailer. The trailer has a GVWR of 3500 lb, which the Sienna is rated to tow with its towing package. I had an independent shop install a fluid-to-air ATF cooler, unfortunately, perhaps, choosing the smallest model as it was recommended for a 3500 lb tow. I was concerned about getting too much cooling in the winter. The van already had an ATF cooler in the radiator. I had them put in an ATF temperature gauge (before the radiator) at the same time. The towed weight of the trailer is several hundred pounds below the GVWR, but it has a front profile that is basically vertical. I have towed the trailer about 20,000 km (yes, I’m in Canada) and done what Toyota calls an ATF change three times. That’s actually a drain the pan and refill with 4 L of ATF, not really a change. Of course, I have no way of knowing how accurate the gauge is, but the highest it’s been on the highway is 220 F on a couple of grades in the BC mountains (Coquihalla highway). The temperature went down as soon as the grade did. It went up to 240 F or so for a few minutes while backing up a steep hill and around a bit of a corner into a storage yard. The van had 38,000 km on it when purchased and is now at 82,000 km.

Enough background. I am writing to ask why it is apparently okay to tow a larger trailer (5000 lb rating) with a Highlander but not a 3500 lb trailer with a Sienna. As far as I can tell, the engine, transmission and weight of the vehicles are basically the same. The internet is rife with posters who advise against towing with a minivan but seem to have no qualms about doing so with a SUV, except the very smallest.

What do you think?

Thanks very much for helping me out with this. I can find no answer to my question on the internet.

George writes:

Sajeev, I enjoy TTAC and your writing. Okay, I succumbed to the blandishments of you Panther lovers (and to fond memories of my father driving his Fords and Lincolns), and bought a 1996 Lincoln Town Car Cartier. The car has about 143,000 miles on it, all in North Carolina. The previous (2nd) owner was reportedly a little old lady, and because of the condition of the driver’s seat she could not have weighed much more than 90 or 95 pounds. It is well taken care of and straight.

This is the kind of video that might suffice as standalone weekend entertainment. After all, braking a truck with your feet is a pretty demonstrably bad idea. But the lovable nerds at Popular Science just had to take it a step further and work out the physics of trying to halt a truck ala Fred Flintstone, noting

Let’s estimate he can push down with a force about a quarter of his weight. If he weighs 200 pounds, this would result in a force of 50 pounds, or 225 N. We also know that the force of friction (F) between his feet and the asphalt depends on the force with which he pushes down (N) and the “coefficient of kinetic friction”(μ) between the soles of his shoes, which we will assume are made of rubber, and the pavement.

F = μN

The μ between rubber and asphalt varies between 0.5 and 0.8. Let’s assume a value of 0.7. Therefore, solving for stopping distance, we get:

D = ½(2100kg)(18m/s)2/(0.7)(225N) = 2160 meters, or over 1.3 miles!

The situation might be improved if he exerted his full 200 pounds, or 900 Newtons, of force against the ground. In that case:

D = 1/2(2100kg)(18m/s)2/(0.7)(900N) = 540 meters (about a third of a mile)

However, the amount of torque exerted on his ankles and knees might make that a problematic proposition.

Surf on over to PopSci for the entire breakdown (no pun intended).

Introduction • Part 1 • Part 2 • Part 3 • Part 4 • Part 5 • Part 6 • Part 7 • Part 8

After installing a junkyard-centric, street-sign-based instrument panel and 20-pound “pullout sound system,” I hit the streets on my post-college-graduation job search. After all, with a newly-minted degree from the University of California in hand and the Bay Area from San Francisco to Concord, Santa Rosa to San Jose as my search area, I’d soon be raking in sufficient Benjamins to install a 6-71-blown 427 in my Chevy, right? Short answer, learned after several hundred increasingly grim job interviews: no. I really feel for today’s recent college grads, since I had it easy compared to what you poor 22-year-old, in-student-loan-debt-up-to-your-nodules bastids are facing… but still, with no income other than the occasional junkyard-wrenchin-fer-cash gig and death-to-soul office temping (more on that later) showing up for me, I felt the abyss (i.e. graduate school) looming ever closer. What to do? Hit the highway!

Since I’ve got ungodly quantities of top-shelf booze thanks to my other job, I figured I’d celebrate my 900th birthday by having a party and pouring said booze down my guests’ throats. A couple of them went overboard on the gift department, including one who made me a coupon for free brake work on my Dodge A100 Hell Project.

I spotted this sticker on a (disc brake-equipped) Nissan pickup in the parking lot of the San Jose North Pick-Your-Part during my last trip to California.

Though an objectively awesome car by any (non-environmental) metric (review forthcoming, I promise) some Corvette ZR1 owners are plagued with a strange brake vibration. Which, thanks to the Corvette Forum, is available for all and sundry to see. But let’s dig a little deeper: bearing in mind the customer involved is a personal friend, and his paraphrased comments are as follows.

When friends of the automobile think about environmental regulation, our minds tend to tend to leap towards emissions. Between energy independence, air quality and the specter of global warming, a number of political agendas focus auto regulations on the tailpipe and drivetrain, driving a number of changes in the industry. But, as the AP reports, engines aren’t the only automotive components that impact the environment. The state of Washington has voted to ban brake pads with more than five percent copper content by 2021, making it the first state in the union to address the accumulation of heavy metals in groundwater through automotive regulation.

Ford says emphatically no, but the evidence (such as it is) indicates certain similarities. Let’s take a look…

And the hits, they keep on coming. Now, brakes of the Prius flake out.

Japan’s transport ministry has received 14 complaints about problems with brakes on Toyota’s latest. The ministry has asked Toyota to investigate the complaints, says the Nikkei [sub.] “Those are purely reported cases, so we still need to investigate to find out where problems really exist,” said a ministry spokesman, who said that the number of complaint over such a short time-span “more than usual.” There is more in the U.S.A.

Yesterday, the Wall Street Journal wrote: “Hell, in modern imagination, is not a place of fiery lakes and acrid fumes. It’s a maze of deposition rooms you can’t escape, where nothing is what it seems. That’s where Toyota has landed.“

Welcome to hell.

Automotive News [sub] is reporting that Toyota will replace or reshape some 3.8m accelerator pedals to reduce the risk of them becoming lodged against floormats. Toyota will also be replacing some floormats as it battles a recent unintended acceleration scare. But far more interesting than the prosaic alterations to pedals and mats is Toyota’s decision to take modifications a step further on certain affected models. AN [sub] explains:

Toyota will install a brake override system on the involved Camry, Avalon, and Lexus ES 350, IS 350 and IS 250 models “as an extra measure of confidence.” The system will shut off engine power if drivers press the accelerator pedal and brake pedal simultaneously.

Oy. More proof that it only takes a few idiots thinking their car is possessed to ruin burnouts for everyone. Well, everyone who owns a slushbox Toyota or Lexus, anyway.