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04-13-2006, 12:15 PM
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#1 |
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Registered User
Join Date: Jun 2005
Location: Slatington, PA
Posts: 536
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67 Drum Brake Fade?
I was sitting at a light yesterday after having driven about 30 minutes on the highway and light traffic. I was stopped on a slight upfhill with my foot on the brake when all of a sudden the pedal sinks, the brake light on the dash comes on and I start rolling backwards!
 I pumped the pedal a bit and stopped the truck, the pedal got firm again. I had no other problems on the way home. I checked the fluid level, it's full. I'm running the original, non-power drum setup all around. Is this just fade?
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67 C10 LWB Stepside- 250cid 6, 3speed |
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04-13-2006, 12:21 PM
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#2 |
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Resident Curmudgeon
 
Join Date: Dec 1999
Location: NH
Posts: 6,664
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Re: 67 Drum Brake Fade?
Time for a new master cylinder my friend. Fade is caused by hot shoes and occurs after repeated braking, basically requiring more pressure to accomplish the job. What you describe is symptomatic of a bad master cylinder
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Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter  Maybe I need to sell some of this crap  Yet another Bozo with a sawz-all |
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04-13-2006, 03:00 PM
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#3 |
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Senior Member
Join Date: Dec 2004
Location: Southern Pines NC
Posts: 3,853
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Re: 67 Drum Brake Fade?
the fluid actually boils because of the heat, when it boils it develops air in the system. Plus the M/C seals could be going bad. Replace, the life you save could be your own
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04-14-2006, 02:16 AM
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#4 |
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its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: 67 Drum Brake Fade?
brake fade is from the hot gasses being released by the brake shoe compound. Not boiling brake fluid.
The problem being described is (as stated before) a bad master cylinder. The piston/bore is worn and letting pressure go around it... kinda like blow by with bad rings on the engine. Replace the master cylinder... dirt cheap at any parts house in town. |
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04-14-2006, 11:34 AM
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#5 | |
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Dork For Days
Join Date: Aug 2005
Location: Dallas
Posts: 407
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Re: 67 Drum Brake Fade?
Quote:
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1972 C20, 402/700R4 - My first classic truck, bought in September 2005. 85% transformed from "Farm" to "Cool" status!  1970 Dodge Challenger 440, 4sp (my other toy) 12.67 @ 117 MPH, with a pathetic 2.022 60' 2007 Dodge Charger SRT-8 2008 Cadillac CTS All-American garage, baby! |
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04-14-2006, 07:39 AM
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#6 |
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Registered User
Join Date: Jun 2005
Location: Slatington, PA
Posts: 536
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Re: 67 Drum Brake Fade?
Thanks for the advice, I'll get on it.
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67 C10 LWB Stepside- 250cid 6, 3speed |
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04-14-2006, 12:30 PM
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#7 |
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I am a Referee of life.
Join Date: Jun 2000
Location: Greensboro N.C.
Posts: 13,993
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Re: 67 Drum Brake Fade?
An old school hot rodders trick was to drill holes in the drums.This allowed the gasses to escape when braking and also promoted cooling the drums/shoes.The need to space the holes evenly is obvious in order to keep the drums balanced.I wish there were a place to get this done since I would love to have my rear drums done.
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The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil" |
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04-14-2006, 01:53 PM
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#8 |
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its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: 67 Drum Brake Fade?
ONly problem with that is it can induce cracking between holes drilled.
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