Author Topic: making stock brakes great again  (Read 3824 times)

Offline zieg85

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    • 73-87 GM squarebody extended cab and conversions up to 91 R/V series
Re: making stock brakes great again
« Reply #15 on: December 20, 2016, 10:42:34 PM »
All I know is there was nothing enjoyable about driving or stopping that truck!

Back in the day some were a handful to stop but something must have been off.  Even on the oval track my car was manual steering and manual brakes.  I would even take the guts out of the right rear so there were 3 wheel braking, still stopped better than most. 
1985 C30 Custom Deluxe Ext. cab 5.7L TH400 3.21 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline gwcrim

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Re: making stock brakes great again
« Reply #16 on: June 26, 2019, 12:25:59 PM »
Thought I'd update this.  I got a new master cylinder and bench bled it.  The brakes work MUCH better now.  Still too much rear bias but not near as bad as before.

Not sure what I'll do next for further improvement.  A proportioning valve?  Might have to.

Offline JohnnyPopper

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Re: making stock brakes great again
« Reply #17 on: June 26, 2019, 05:53:03 PM »
Wow it took 3 years to bleed?  ::)

Does anyone make an aftermarket anti-lock system? I would consider it, the rear locks up on my K10 especially after a car wash.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline VileZambonie

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Re: making stock brakes great again
« Reply #18 on: June 27, 2019, 06:10:18 AM »
RWAL came on these trucks. I think they are garbage systems but they are out there if one was so inclined.

If your brake system is 100% perfect and still locking up replace the combination valve but something sounds off if it is impacted by a car wash.
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Offline JohnnyPopper

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Re: making stock brakes great again
« Reply #19 on: June 27, 2019, 05:33:53 PM »
You're probably right, might need to crack one open.

Just thought the high water pressure is finding it's way inside the drum and causing it to seize.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Online roundhouse

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Re: making stock brakes great again
« Reply #20 on: July 04, 2019, 09:36:35 AM »
Some times the rear brakes will lockup it they axle seals are leaking and oil gets onto the shoes and drums

I know it doesn’t make sense that oil would make them lock up
But it does

It that does not cure it you may need to install an adjustable prop valve on the rear

And there are lots of kits to convert the rear to discs

Offline gwcrim

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Re: making stock brakes great again
« Reply #21 on: September 29, 2019, 03:12:03 PM »
I have a suspicion that a brake drum is out of round.  Have to find someone to turn them.  That sure would cause the same rear tire to skid.

Offline gwcrim

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Re: making stock brakes great again
« Reply #22 on: December 02, 2019, 05:03:50 PM »
Latest update.  I have the bed off so I decided to closely examine the rear brakes.  Seems as though the drums had probably never, ever been turned.  They appeared to be round but somewhat worn @ 70K miles.  I ordered new drums.  No one locally likes to turn them any more.

I'm hoping that the new drums fix the squishy pedal feel as well as stop the lock up.  If not, I'll have to try disks.

Online MIKE S

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Re: making stock brakes great again
« Reply #23 on: December 02, 2019, 09:32:21 PM »
Something else you may want to think about is that your rear brakes are locking up because your front brakes are not working good enough. In other words you are pressing on your brakes so hard that your back brakes are locking before your front brakes do. This can be caused by not having matched grades of braking material front and rear. If you have a metallic type pad on the front you have to get them hot for them to grab and they typically have a harder pedal. The rotors may not have a good non directional pattern on them. I’ve seen a lot of offshore rotors without a good finish. If you didn’t “burnish” in the front brakes when you put them on they could be glazed and that could cause some problem.
« Last Edit: December 02, 2019, 09:37:49 PM by MIKE S »

Offline gwcrim

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Re: making stock brakes great again
« Reply #24 on: December 03, 2019, 05:12:45 PM »
This can be caused by not having matched grades of braking material front and rear.

I've thought about that. There aren't many selections of rear brake pad materials.  I have ceramic pads on front.  Cleaner for the mag wheels, ya know?

Online MIKE S

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Re: making stock brakes great again
« Reply #25 on: December 03, 2019, 09:28:54 PM »
I had problems on my 87 when I changed rear shoes. I tried O’Reillys and had a heck of a time. You could tell the friction material was very inferior. The forward or short shoe was not right. The friction material was attached to low on the shoe and I just could not get them to work right after a couple of sets. I finally found a set of AC/DELCO shoes that were far superior. Fit perfect and was able to adjust those for a good pedal with no lock up. Another thing to look at is the wheel cylinder. A larger bore would give you a softer pedal but more apply pressure to the shoes. You could have been given the wrong cylinders when you replaced them. They are different bores between 11 inch and 11 5/32 shoes.