<div dir="ltr">Sounds about right Phil. I had a '96 F-250 (old-style, pre Super Duty) with rear drums. Around the late 90's or early 2000's as you mentioned I started seeing rear discs on pickups. The Google will tell you about the pro's and con's of drums vs discs in mostly layman's terms, but one thing I don't see mentioned are the design parameters of ABS, traction control, and stability control. Of course you can have ABS on a drum-brake system; many exist. But discs have advantages: better heat dissipation and more linear response (brake force vs. line pressure). I am guessing you can probably cycle ABS faster on discs, as drums have a self-energizing effect on the leading shoe and it probably takes longer to pull the shoe out of contact. Traction control and stability control systems take various forms, and some will automatically "tap" the brake on a spinning wheel. Do that often enough and heat dissipation is going to be a primary concern.<div><br></div><div>SO</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Dec 30, 2019 at 12:57 PM Phil Auten <<a href="mailto:pga2@basicisp.net">pga2@basicisp.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>James,</p>
<p>I drive a 2009 F150 and it has 4 wheel disc brakes. I believe
those became standard sometime in the late 90's or early 2000's.</p>
<p>Phil in TX</p>
<br>
<div>On 12/30/2019 7:18 AM, James Peck
wrote:<br>
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<blockquote type="cite">
<div>
<p class="MsoNormal">I was not aware a standard exists requiring
semi tractors to stop from 60 MPH in 250 feet and that some
fleets are pushing to stop in 225 feet. In the case of
European ag tractors that haul trailers on the highway at
higher speeds I am guessing that all wheel braking will be the
new norm.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><a href="https://www.ccjdigital.com/air-disc-brakes-likely-to-become-most-popular-option-but-drums-will-not-go-away/" target="_blank">https://www.ccjdigital.com/air-disc-brakes-likely-to-become-most-popular-option-but-drums-will-not-go-away/</a><u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I see rear disc brake conversion kits for
collector automobiles like Jeep Cherokees and Ford Mustangs. I
was looking at new F150s recently. Even the optionless F150
models having manual door locks and vinyl seat covers have
rear disk brakes.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">The Shelby Ford win at LeMans involved
building an entire spindle-hub-rotor-caliper-pad-cylinder
assembly that could be changed out in a short time. I do not
know how they handled the brake bleeding issue unless they
used quick disconnect fittings on the brake lines.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">As a kid, I used to go to Burton Ohio and
ride on a traction engine pulled wagon. The ride was not
totally silent. Sone years ago a traction engine boiler
exploded at the Medina County fair, a couple of counties west
of there. That event has had a lot of repercussions for the
showing of traction engines.<u></u><u></u></p>
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