Author Topic: Which Drum Brakes do I have?  (Read 1158 times)

Offline buter1ma

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Which Drum Brakes do I have?
« on: October 02, 2019, 06:53:35 AM »
I have a 86 C10 Custom 3 on the tree trans, 4.3 engine. Bare bones of C10s. I am missing the parking brake strut for one of my drum brakes and I want to do a complete replacement of everything. When I measure my pads that aren't 2in or 2.75, they are over 2in. the RPO code for my power brakes is 1J50. I don't really trust whats on my truck because someone didn't install the brake strut to begin with.  Anyone give me some insight on what to look for to get correct parts? Thank you.

Offline Irish_Alley

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Re: Which Drum Brakes do I have?
« Reply #1 on: October 02, 2019, 11:12:03 AM »
i have this
http://forum.73-87chevytrucks.com/smforum/index.php?topic=28592.0

but its been a few years since i updated it. maybe i can find the pictures again and get it updated
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Offline bd

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Re: Which Drum Brakes do I have?
« Reply #2 on: October 02, 2019, 11:39:25 AM »
Measure and post the ID of the drum and the width of the shoes.  Post an image of the rear brakes as they are assembled on the "complete" side when you have the drum off.

There should be a brake code on the SPID label that ID's the original brakes as built by the factory (e.g., JB3, JB5, JB6, JB7, etc).  What is it?
« Last Edit: October 02, 2019, 11:42:40 AM by bd »
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline buter1ma

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Re: Which Drum Brakes do I have?
« Reply #3 on: October 02, 2019, 02:11:18 PM »
I have attached a pic of my resouvoir and of the RPO.

Where would I find the SPID?

Offline Irish_Alley

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Re: Which Drum Brakes do I have?
« Reply #4 on: October 02, 2019, 08:21:36 PM »
Since you have the plastic reservoir then you have either jb1,3 or 5.

You can try to find the gvwr and match it up to this
JB1 BRAKE, MANUAL, DISC/DRUM, 4300 LBS
JB3 BRAKE, POWER, DISC/DRUM, 4600 LBS
JB5 BRAKE, POWER, DISC/DRUM, 6400 LBS

Also the jb1 and 3 will have the brake shoes that are 2" like you know and depending on the maker of the shoes I would say you have 1 or 3 and that trans I don't think it was really made to "work" and imo would keep the gvwr down
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline buter1ma

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Re: Which Drum Brakes do I have?
« Reply #5 on: October 03, 2019, 07:18:46 AM »
I am unsure what you mean when you say  "that trans I don't think it was really made to "work" and imo would keep the gvwr down". 

Offline Irish_Alley

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Re: Which Drum Brakes do I have?
« Reply #6 on: October 03, 2019, 07:51:54 AM »
dont quote me on it but the trans you have (dont know which one it is for sure) but i know its not the sm465 which was meant to work and haul some weight. the sm465 can be found in all the series of trucks unlike the column shifted manual trans.
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline bd

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Re: Which Drum Brakes do I have?
« Reply #7 on: October 03, 2019, 08:24:49 AM »
One of your SPID labels is imaged below.  There should be another with additional codes.  JB1 is manual brakes.  The power booster looks like a single diaphragm, so your truck probably was built with JB3 power brakes.  Accordingly, the rear shoes should be 11" diameter by 2" wide, but you should measure what you have to verify.  The factory part number for the parking brake struts for JB3 is 357893.  The left and right sides are interchangeable.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline buter1ma

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Re: Which Drum Brakes do I have?
« Reply #8 on: October 04, 2019, 07:19:34 AM »
Any idea where I can find one? I have looked online and all I can find is one for JB5 or JB6 brakes. Ill need to spring too.

Offline bd

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Re: Which Drum Brakes do I have?
« Reply #9 on: October 04, 2019, 07:35:08 AM »
The spring should come in a hardware kit.  The struts virtually never wear out, so scour the wrecking yards.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline buter1ma

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Re: Which Drum Brakes do I have?
« Reply #10 on: October 04, 2019, 08:32:39 AM »
What a pain in the butt. I am just missing it on one side. I cant believe they dont make them for these brakes anymore.

Offline zieg85

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Re: Which Drum Brakes do I have?
« Reply #11 on: October 04, 2019, 10:23:52 AM »
What a pain in the butt. I am just missing it on one side. I cant believe they dont make them for these brakes anymore.
Take a picture of what you need.  I have buckets of stuff I've saved over the years, I can see if I have an extra one for you
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1986 C10 under construction
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Offline buter1ma

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Re: Which Drum Brakes do I have?
« Reply #12 on: October 05, 2019, 08:12:13 AM »
Thank you so much. Iíll try to get a picture this weekend.

Offline bd

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Re: Which Drum Brakes do I have?
« Reply #13 on: October 05, 2019, 10:26:15 AM »
Include dimensions in the post.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline buter1ma

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Re: Which Drum Brakes do I have?
« Reply #14 on: October 06, 2019, 01:13:04 PM »
Here are two pics. One is the overall the other is the length measurement.