Need some help~~~ - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Huck · 02-28-2007, 07:45 PM

I need some help with brake pedal position. My 72 4x4 has the brake pedal sitting about 3-3.5 inches off the floor. this measurement is from the floor to the bottom of the pedal pad. My 70 truck has the brake pedal sitting closer to 5" off the floor. Can I get some measurement imput to see what some others have in inches---off the floor in rest position?? Thanks--huck

JimKshortstep4x4 · 03-01-2007, 06:27 AM

I measured two of our 4x4 trucks, (a 71 and a 72). Both pedals measured 3 1/2"- 3 3/4" from the floor to the bottom of the pedal.

If your rod to the booster has enough threads, there may be some adjustment to bring the pedal up but the thread engagement needs to remain adequate.

Jim

**jamie72** · 03-02-2007, 05:04 PM

mine in the blazer is like 3 3/4 from floor

1fast71 · 03-02-2007, 05:11 PM

get some diffrent pedles maybe?

Longhorn Man · 03-02-2007, 05:15 PM

Warren, sounds like you have a manual brake truck, and a power brake truck? Manual brakes is supposed to be higher IIRC.

Huck · 03-03-2007, 11:28 AM

Well unfortunately like some many of these trucks---stuff---has been done to both. The Blazer from hell is still giving me brake issues like pass rear locking up when applying brakes--replaced Master cylinder, new proportioning valve, new rear wheel cylinders, new front calipers--pads--shoes--etc. The hoses were new 4 years ago and look it. Strange issue in the drivers rear brake---front shoe is worn 1/2 way while rear shoe looks new as if wheel cylinder is not pushing the back shoe yet with drum off, you can push the brake and watch the rear shoe go back!!! WTF
If I hit the brakes a bit harder, the front discs don't seem to do much and the right rear just LOCK up hard. No telling what brake stuff is orignal as 2PO back did a total restore and there is a lot of frankenstein potential.
When comparing to my 70 2x4 ---that too had a lot of swapping done like 72 BB Cab---original drum brakes front and back---etc.
Will try to bleed today----one more time!!

watahyahknow · 03-03-2007, 11:38 AM

does a blazer has a loadajusting brakevalve on the rearaxle ?
it might be that this is the culprit .
on european cars its located about in the midle of the rearaxle and has the brakelines going in and a lever bolted on the rearaxle as the car squats during loading the device put more linepressure toward the rearbrakes

**WorkinLonghorn** · 03-03-2007, 04:03 PM

My '69 GM shop manual says " brake peddle reserve travel" is set with 90lbs pressure (engine running on power brake trucks) and should be minimum 3.5" manual,1.25 power.That's distance to floor from back of peddle.

02-28-2007, 07:45 PM	#1
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	Need some help~~~ I need some help with brake pedal position. My 72 4x4 has the brake pedal sitting about 3-3.5 inches off the floor. this measurement is from the floor to the bottom of the pedal pad. My 70 truck has the brake pedal sitting closer to 5" off the floor. Can I get some measurement imput to see what some others have in inches---off the floor in rest position?? Thanks--huck

03-01-2007, 06:27 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Need some help~~~ I measured two of our 4x4 trucks, (a 71 and a 72). Both pedals measured 3 1/2"- 3 3/4" from the floor to the bottom of the pedal. If your rod to the booster has enough threads, there may be some adjustment to bring the pedal up but the thread engagement needs to remain adequate. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

03-02-2007, 05:04 PM	#3
jamie72 Senior Member Join Date: Apr 2000 Location: madison indiana Posts: 3,839	Re: Need some help~~~ mine in the blazer is like 3 3/4 from floor __________________ jamie72 72 BB cheyenne -- Restoration getting started.. member #807 http://www.myspace.com/whitetailobsession www.antlertalk.com

03-02-2007, 05:11 PM	#4
1fast71 Registered User Join Date: Dec 2006 Location: medford oregon Posts: 152	Re: Need some help~~~ get some diffrent pedles maybe?

03-02-2007, 05:15 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Need some help~~~ Warren, sounds like you have a manual brake truck, and a power brake truck? Manual brakes is supposed to be higher IIRC.

03-03-2007, 11:28 AM	#6
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	Re: Need some help~~~ Well unfortunately like some many of these trucks---stuff---has been done to both. The Blazer from hell is still giving me brake issues like pass rear locking up when applying brakes--replaced Master cylinder, new proportioning valve, new rear wheel cylinders, new front calipers--pads--shoes--etc. The hoses were new 4 years ago and look it. Strange issue in the drivers rear brake---front shoe is worn 1/2 way while rear shoe looks new as if wheel cylinder is not pushing the back shoe yet with drum off, you can push the brake and watch the rear shoe go back!!! WTF If I hit the brakes a bit harder, the front discs don't seem to do much and the right rear just LOCK up hard. No telling what brake stuff is orignal as 2PO back did a total restore and there is a lot of frankenstein potential. When comparing to my 70 2x4 ---that too had a lot of swapping done like 72 BB Cab---original drum brakes front and back---etc. Will try to bleed today----one more time!!

03-03-2007, 11:38 AM	#7
watahyahknow Registered User Join Date: Jul 2006 Location: the netherlands europe Posts: 4,335	Re: Need some help~~~ does a blazer has a loadajusting brakevalve on the rearaxle ? it might be that this is the culprit . on european cars its located about in the midle of the rearaxle and has the brakelines going in and a lever bolted on the rearaxle as the car squats during loading the device put more linepressure toward the rearbrakes __________________ i got a job again and having fun at it too idea's for the trucks and the order of things to do are taking shape and get closer to being realized , a few more months and i be able to start building for real i complete 2 of the trucks intoo running fashion one custom and one basicly stock the thirth will be sacrificed for parts

03-03-2007, 04:03 PM	#8
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,861	Re: Need some help~~~ My '69 GM shop manual says " brake peddle reserve travel" is set with 90lbs pressure (engine running on power brake trucks) and should be minimum 3.5" manual,1.25 power.That's distance to floor from back of peddle. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, 2nd owner, Work-Truck supreme. Best $300 I ever spent.



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