What master cylinder and booster do I get?

[C10SLEY]

'83 C10 Silverado:

I inherited this truck, a few people before me had it, so I keep finding odd things that were done to it not factree. The most recent being th master cylinder. I think i have a collapsed line, and I didn't like how the MC and hard lines looked, so I cut them and tried to replace the MC. It didn't fit. Rod was too long, bolts were long enough to hold the new MC. So I returned it and now i'm thinking, "what brake system do I want to go with rn?" I don't think i'm ready for a big investment (slowly restoring the truck). So i just need something helps the truck stop.

It's disc/drum, wanting a clean-looking engine bay (already is), what is gunna work?

Thanks for the guidance.

 

[SirRobyn0]

'83 C10 Silverado:

I inherited this truck, a few people before me had it, so I keep finding odd things that were done to it not factree. The most recent being th master cylinder. I think i have a collapsed line, and I didn't like how the MC and hard lines looked, so I cut them and tried to replace the MC. It didn't fit. Rod was too long, bolts were long enough to hold the new MC. So I returned it and now i'm thinking, "what brake system do I want to go with rn?" I don't think i'm ready for a big investment (slowly restoring the truck). So i just need something helps the truck stop.

It's disc/drum, wanting a clean-looking engine bay (already is), what is gunna work?

Thanks for the guidance.

Other than to say order a master for 83 C10 I'm not sure whatelse to say. If you still have the old master cylinder you could try to find numbers on it that might be useful to find yourself the correct unit. Uploading some pictures of the booster and old master wouldn't hurt either. Someone might be able to identify specifics.

 

[Keith Seymore]

What's the GVW rating on the truck?

Does it have the 1" or the 1.25" front rotors?

K

 

[C10SLEY]

What's the GVW rating on the truck?

Does it have the 1" or the 1.25" front rotors?

K

GVW rating i found to be 5001-6000 and I'm not sure what size the rotors are. I'll have to measure them next time I have the wheels off. Curious why do you ask? I'm trying to understand the physics of it all?

 

[C10SLEY]

Couple photos of before and after I took the master cylinder off. Thought I could just put a new one from O’Reilly on, but flanges too think and rod is too long. Realized it had a brake booster in it from the factory and wanna restore it to factory things or better.

 

[Keith Seymore]

GVW rating i found to be 5001-6000 and I'm not sure what size the rotors are. I'll have to measure them next time I have the wheels off. Curious why do you ask? I'm trying to understand the physics of it all?

The brake systems are based on GVW.

You may have heard people talking about JB5 or JB6 or JB8 or whatever; that's the number you are trying to get to. ("JBx" is vacuum; "JDx" is hydroboost.) JB1 is manual; JB3 is the smallest power system and is kinda rare so I'm always surprised when I see one; most light duty trucks are either JB5 or JB6.

I'm posting the brake chart for the '85 C10s, just because I already have it scanned and the format is a little easier to follow, so you can see how this works.

This is the chart that the brake engineer developed and used in order to release the parts for production and service.

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[Keith Seymore]

Here's what the '83 chart looks like:

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[Keith Seymore]

So based on a deep dive into the '83 chart I would recommend:

M/C part number 18008065, code ZF
28.6mm bore dia; 37.42mm stroke

Booster is 18010581, tandem vacuum, code FD (known as a model "240T").

K

You must be registered for see images attach

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[C10SLEY]

Super thorough explanations, Keith! Thank you so much! I went ahead and purchased a MC and BB from Ebay, and I will see how that goes. I will keep y'all updated.

 

[C10SLEY]

Went with the cheapest options from EBay for MC and BB. Rod coming from the booster was short, and previous truck owner had welded a different through pin on the brake bar. I engineered what I needed with an eye bolt, nylon washer, and coupler. Should work great. Gunna bleed the MC, run hard lines tomorrow if I can get these daggone tube nuts out of the proportioning valve.
Also may try to create a dust boot for the firewall to block some air and noise from coming through.
Stay tuned!

 

[C10SLEY]

Replaces both front rubber lines and the single rear while I was at it.

 

[Fastduramax]

Nice work and where did you find these charts ? I'd like to find one for 86 K10, google search no results....

 

[Keith Seymore]

Those only exist at my house. They are the charts the engineers used to release the part numbers for production and service. I have them back to 1969.

I knew they existed and that one of the brake system engineers had them. I was bugging him so much that he let me borrow them.

Somehow they never made it back.

I plan to donate them to the GM Heritage Center archive when I'm done.

K

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[Keith Seymore]

1986 K10:

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[Ken B]

keith you are wealth of information....Thanks for sharing your career experience and knowledge. keeps us rookies outta the weeds