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

dave68 · 06-09-2013, 11:47 AM

Hi all, I need help from the experts-that's you! I have a 68 LWB C10 that underwent a frame-off resto. The truck came with 11"X2" drums on all 4 corners. During the resto I replaced: lines, hoses, wheel cylinders, master cylinder, shoes and drums with new. The push rod and parking brake cable are adjusted properly and it has been bled repeatedly, with no air or leaks noticed. The auto-adjusters work as advertised. That said, here is the problem: I have to almost stand on the brake pedal to make the truck come to a stop. It does not swerve and stops straight and true when the brakes are applied even during high speed stops. All the shoes appear to be contacting the entire drum surface and are not glazed... I have a theory: The friction material is too hard? -Has anyone else had this problem in the past? I do not want to upgrade to dics or add power assist, as the truck was restored to almost original. Before the resto, the orginal 45 year old brakes stopped the truck with little effort, so it has to be a recent addition causing the problem... Please let me know what you think. -Dave

bugmasta · 06-09-2013, 12:59 PM

Get a softer shoe. They won't last as long and will be dirtier, but will stop better. Old shoe composites were softer because EPA was not a factor. Go to napa and ask for the softest shoe they got.

I converted my truck to discs, but can speak from experience with my 65 VW that still runs all drums that this is key to get soft shoes.
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Shyguy · 06-09-2013, 01:09 PM

You probably did, but I will ask the question any way. Did you clean the drums real good with brake cleaner before you installed them?

Like others said, it is a problem with too hard of a shoe. In the old days we use to arch the new shoes to make sure they were making good contact, but I don't that has to be done on newer shoes.

dave68 · 06-09-2013, 03:06 PM

Quote:

Originally Posted by bugmasta

Get a softer shoe. They won't last as long and will be dirtier, but will stop better. Old shoe composites were softer because EPA was not a factor. Go to napa and ask for the softest shoe they got.

I converted my truck to discs, but can speak from experience with my 65 VW that still runs all drums that this is key to get soft shoes.
Posted via Mobile Device

Awesome, this is what I thought as well. Thanks for the advice, I'll hit up NAPA in the AM! -Dave

dave68 · 06-09-2013, 03:10 PM

Quote:

Originally Posted by Shyguy

You probably did, but I will ask the question any way. Did you clean the drums real good with brake cleaner before you installed them?

Like others said, it is a problem with too hard of a shoe. In the old days we use to arch the new shoes to make sure they were making good contact, but I don't that has to be done on newer shoes.

Hi, yes they were cleaned before installation. I agree, the shoe friction material is too hard. The EPA put a stop to brake arching a long time ago due to the asbestos dust they produced. Eventually, the drum will wear the shoes into the matching contour. Arching made this process wayyy faster. Thank you for the reply, I'll start the hunt tomorrow to find a softer shoe. -Dave

Hard_Rain420 · 06-09-2013, 08:42 PM

I've had the similar problem before and found out the brake booster was bad assuming you have pwr. brakes.

68gmsee · 06-09-2013, 08:56 PM

^ Yeah, do you have power brakes? A defective booster will do it.

Now if you don't have power brakes, then as mentioned above, the material they're made of has a lot to do with the stopping power. I had a similar problem on one of mine and wound up having to go to different brake shoe manufacturer.

dave68 · 06-11-2013, 06:00 PM

Hi all, it was indeed the brake shoe material. I could not get a straight answer out of the parts store folks, as they just sell parts, and don't always know a whole lot about them. I then called the service techs at Raybestos and they told me for that particualr application I would require a soft organic shoe, P/N: 280RP or 280RR. Unfortunately, they no longer make these type of shoes. I did luck out and get the last set Rock Auto had on the shelf. I installed them this afernoon, and depite not being broke in yet, are way better than the semi-metalic Professional Grade shoes that had been on there for weeks. Thanks again, I appreciate your insight, all better. -Dave

06-09-2013, 11:47 AM	#1
dave68 Registered User Join Date: Jun 2011 Location: Buffalo, Mo Posts: 14	Hard brake pedal... Hi all, I need help from the experts-that's you! I have a 68 LWB C10 that underwent a frame-off resto. The truck came with 11"X2" drums on all 4 corners. During the resto I replaced: lines, hoses, wheel cylinders, master cylinder, shoes and drums with new. The push rod and parking brake cable are adjusted properly and it has been bled repeatedly, with no air or leaks noticed. The auto-adjusters work as advertised. That said, here is the problem: I have to almost stand on the brake pedal to make the truck come to a stop. It does not swerve and stops straight and true when the brakes are applied even during high speed stops. All the shoes appear to be contacting the entire drum surface and are not glazed... I have a theory: The friction material is too hard? -Has anyone else had this problem in the past? I do not want to upgrade to dics or add power assist, as the truck was restored to almost original. Before the resto, the orginal 45 year old brakes stopped the truck with little effort, so it has to be a recent addition causing the problem... Please let me know what you think. -Dave

06-09-2013, 12:59 PM	#2
bugmasta Registered User Join Date: Aug 2009 Location: North Bend, WA Posts: 272	Re: Hard brake pedal... Get a softer shoe. They won't last as long and will be dirtier, but will stop better. Old shoe composites were softer because EPA was not a factor. Go to napa and ask for the softest shoe they got. I converted my truck to discs, but can speak from experience with my 65 VW that still runs all drums that this is key to get soft shoes. Posted via Mobile Device __________________ 68 c20 build: http://67-72chevytrucks.com/vboard/s...d.php?t=358130 Club longbed ...cause girls like'em long!!!!!

06-09-2013, 01:09 PM	#3
Shyguy Junior Member Join Date: Dec 2006 Location: Southeast Missouri Posts: 2,436	Re: Hard brake pedal... You probably did, but I will ask the question any way. Did you clean the drums real good with brake cleaner before you installed them? Like others said, it is a problem with too hard of a shoe. In the old days we use to arch the new shoes to make sure they were making good contact, but I don't that has to be done on newer shoes. __________________ '67 Chevy C-20 short stepper - build complete, 454/SM-465. '75 C-30 Single Cab DRW-350 small block/NP-435. '77 GMC-6500 Dump Truck, 427 Tall Deck. '92 GMC K-3500 Duallie, 454/4L80E.

06-09-2013, 08:42 PM	#6
Hard_Rain420 Registered User Join Date: Oct 2012 Location: Melbourne FL Posts: 201	Re: Hard brake pedal... I've had the similar problem before and found out the brake booster was bad assuming you have pwr. brakes.

06-09-2013, 08:56 PM	#7
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Hard brake pedal... ^ Yeah, do you have power brakes? A defective booster will do it. Now if you don't have power brakes, then as mentioned above, the material they're made of has a lot to do with the stopping power. I had a similar problem on one of mine and wound up having to go to different brake shoe manufacturer. __________________ 68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive...

06-11-2013, 06:00 PM	#8
dave68 Registered User Join Date: Jun 2011 Location: Buffalo, Mo Posts: 14	Re: Hard brake pedal... Hi all, it was indeed the brake shoe material. I could not get a straight answer out of the parts store folks, as they just sell parts, and don't always know a whole lot about them. I then called the service techs at Raybestos and they told me for that particualr application I would require a soft organic shoe, P/N: 280RP or 280RR. Unfortunately, they no longer make these type of shoes. I did luck out and get the last set Rock Auto had on the shelf. I installed them this afernoon, and depite not being broke in yet, are way better than the semi-metalic Professional Grade shoes that had been on there for weeks. Thanks again, I appreciate your insight, all better. -Dave



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