Hard brake pedal - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DZL1 · 02-01-2009, 11:39 PM

Newbie here. I just picked up a 72 C-10, V-8, swb, 2wd, automatic tranny. The brakes are hard. Was wondering if anybody can give me some insight as to what the problem or problems might be? Thanks in advance.

DZL1.

68gmsee · 02-01-2009, 11:47 PM

Welcome to the site...

Can you give us a little more info. Do you have power brake booster or is it manual brakes? Also, what do you mean by "hard?" Is the pedal hard to depress or is it just plain hard to stop the truck.

Bob 68327 · 02-01-2009, 11:50 PM

First of all Welcome !!!Asuming they are power . First check the vac line to the booster and the elbow that goes in the booster you can check it by removing it and make sure air only goes through it one way . If this checks out I would say it's time for a new booster. Bob

DZL1 · 02-01-2009, 11:54 PM

Thank you for the greeting. Unfortunately I'm not sure if power or manual. How can I tell? The brake pedal is hard to depress, therefore making it hard to stop. Thanks again.

DZL1.

DZL1 · 02-01-2009, 11:56 PM

Thanks, I will try that tomorrow, assuming they are power.

DZL1.

Bob 68327 · 02-02-2009, 12:02 AM

under the hood it will look like this if they are power pic.1 Non Power pic.2 Bob

DZL1 · 02-02-2009, 12:35 AM

Great pics! Well that answers that question. I have power, and I will try your suggestion. Thanks.

DZL1.

Bob 68327 · 02-02-2009, 08:45 PM

Glad to help out .

DZL1 · 02-03-2009, 12:14 PM

Ok Bob, I removed the elbow from the booster and it has good vacuum. So by your assumption, i will need a new booster. Correct or could it be something else? Thanks.

DZL1.

68gmsee · 02-03-2009, 02:52 PM

Here's some thing you can try: http://www.mpbrakes.com/technical-su...ng-drum-02.cfm

There's a possibility that the master cylinder is defective or brakes contaminated. Eliminate all of the easyily checked/observed mechanical things first. Power boosters are expensive unless you can find one in a junkyard.

OrangeCrush1970 · 02-03-2009, 03:09 PM

Dont buy anything new until you:

1 Check your brake fluid level (1/4" below top)
2 inspect your brakes / pads / adjust your drums
3 inspect your brake lines for leaks and cracking
4 inspect your vacum line from the brake booster to your manifold for cracks / leaks.
5 bleed your brake system.

These are all things that you need to do b/f you go out buying new parts...plus it's the cheapest way to locate your issue.

I had this same problem last week. We bled the brakes...not the problem. I then changed my vacum line to the brake booster and applied gasket sealer where the check valve (elbow that you spoke of) inserts into the brake booster. I then adjusted my brakes (drums).

Problem solved. Hope this helps!

DZL1 · 02-03-2009, 08:05 PM

Thank you guys for taking the time to answer my question. Orange Crush, my fluid level is lower than what you suggest, will fill. Brake lines are not cracked. will inspect brake pads. Vacuum line is fine. Will check vacuum pressure.

68gmsee, thanks for the link. My 72 has disc front and drum rear. I'm assuming the suggestions on that link will work on disc. It stated drum front and rear.

Thanks again guys.

DZL1.

02-01-2009, 11:39 PM	#1
DZL1 One day..... Join Date: Aug 2008 Location: Ocala, FL. Posts: 702	Hard brake pedal Newbie here. I just picked up a 72 C-10, V-8, swb, 2wd, automatic tranny. The brakes are hard. Was wondering if anybody can give me some insight as to what the problem or problems might be? Thanks in advance. DZL1.

02-01-2009, 11:47 PM	#2
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Hard brake pedal Welcome to the site... Can you give us a little more info. Do you have power brake booster or is it manual brakes? Also, what do you mean by "hard?" Is the pedal hard to depress or is it just plain hard to stop the truck.

02-01-2009, 11:50 PM	#3
Bob 68327 72 Chevelle Club Join Date: Jun 2007 Location: Newton , Iowa Posts: 2,052	Re: Hard brake pedal First of all Welcome !!!Asuming they are power . First check the vac line to the booster and the elbow that goes in the booster you can check it by removing it and make sure air only goes through it one way . If this checks out I would say it's time for a new booster. Bob __________________ I Have The Right To Remain Silent,But Lack The Ability 1972 Chevelle ... Mine 2006 Trailblazer... Hers 2002 Buick century ... Kids 2002 K1500 Z-71 EXT CAB ... Daily Driver 2005 Rockwood Roo ... For Camping 1974 Harley-Davidson XLH Sportster 84'' stroker Last edited by Bob 68327; 02-01-2009 at 11:50 PM.

02-01-2009, 11:54 PM	#4
DZL1 One day..... Join Date: Aug 2008 Location: Ocala, FL. Posts: 702	Re: Hard brake pedal Thank you for the greeting. Unfortunately I'm not sure if power or manual. How can I tell? The brake pedal is hard to depress, therefore making it hard to stop. Thanks again. DZL1.

02-01-2009, 11:56 PM	#5
DZL1 One day..... Join Date: Aug 2008 Location: Ocala, FL. Posts: 702	Re: Hard brake pedal Thanks, I will try that tomorrow, assuming they are power. DZL1.

02-02-2009, 12:02 AM	#6
Bob 68327 72 Chevelle Club Join Date: Jun 2007 Location: Newton , Iowa Posts: 2,052	Re: Hard brake pedal under the hood it will look like this if they are power pic.1 Non Power pic.2 Bob Attached Images __________________ I Have The Right To Remain Silent,But Lack The Ability 1972 Chevelle ... Mine 2006 Trailblazer... Hers 2002 Buick century ... Kids 2002 K1500 Z-71 EXT CAB ... Daily Driver 2005 Rockwood Roo ... For Camping 1974 Harley-Davidson XLH Sportster 84'' stroker

02-02-2009, 12:35 AM	#7
DZL1 One day..... Join Date: Aug 2008 Location: Ocala, FL. Posts: 702	Re: Hard brake pedal Great pics! Well that answers that question. I have power, and I will try your suggestion. Thanks. DZL1.

02-02-2009, 08:45 PM	#8
Bob 68327 72 Chevelle Club Join Date: Jun 2007 Location: Newton , Iowa Posts: 2,052	Re: Hard brake pedal Glad to help out . __________________ I Have The Right To Remain Silent,But Lack The Ability 1972 Chevelle ... Mine 2006 Trailblazer... Hers 2002 Buick century ... Kids 2002 K1500 Z-71 EXT CAB ... Daily Driver 2005 Rockwood Roo ... For Camping 1974 Harley-Davidson XLH Sportster 84'' stroker

02-03-2009, 12:14 PM	#9
DZL1 One day..... Join Date: Aug 2008 Location: Ocala, FL. Posts: 702	Re: Hard brake pedal Ok Bob, I removed the elbow from the booster and it has good vacuum. So by your assumption, i will need a new booster. Correct or could it be something else? Thanks. DZL1.

02-03-2009, 02:52 PM	#10
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Hard brake pedal Here's some thing you can try: http://www.mpbrakes.com/technical-su...ng-drum-02.cfm There's a possibility that the master cylinder is defective or brakes contaminated. Eliminate all of the easyily checked/observed mechanical things first. Power boosters are expensive unless you can find one in a junkyard. Last edited by 68gmsee; 02-03-2009 at 02:54 PM.

02-03-2009, 03:09 PM	#11
OrangeCrush1970 Registered User Join Date: Jun 2007 Location: Smyrna, GA Posts: 709	Re: Hard brake pedal Dont buy anything new until you: 1 Check your brake fluid level (1/4" below top) 2 inspect your brakes / pads / adjust your drums 3 inspect your brake lines for leaks and cracking 4 inspect your vacum line from the brake booster to your manifold for cracks / leaks. 5 bleed your brake system. These are all things that you need to do b/f you go out buying new parts...plus it's the cheapest way to locate your issue. I had this same problem last week. We bled the brakes...not the problem. I then changed my vacum line to the brake booster and applied gasket sealer where the check valve (elbow that you spoke of) inserts into the brake booster. I then adjusted my brakes (drums). Problem solved. Hope this helps! __________________ *Rottenwood Garage* 1970...71...72 C1500 aka Orange aka Sideshow Bob 540 BB Straub Roller Cam, AFR Magnums, XP 950, TKO 600 2 Tons of Fun

02-03-2009, 08:05 PM	#12
DZL1 One day..... Join Date: Aug 2008 Location: Ocala, FL. Posts: 702	Re: Hard brake pedal Thank you guys for taking the time to answer my question. Orange Crush, my fluid level is lower than what you suggest, will fill. Brake lines are not cracked. will inspect brake pads. Vacuum line is fine. Will check vacuum pressure. 68gmsee, thanks for the link. My 72 has disc front and drum rear. I'm assuming the suggestions on that link will work on disc. It stated drum front and rear. Thanks again guys. DZL1.



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