Author Topic: 84 C10 Brakes  (Read 1749 times)

Offline SUX2BU99

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Re: 84 C10 Brakes
« Reply #105 on: August 05, 2018, 12:55:08 AM »
This is a good discussion. Sorry to interrupt your thread but what visual difference does the JB3 vs JB5 master cylinder have? I have a hard pedal after taking my C10 out of winter storage and I know the front brakes are dragging but I don't feel it pull to one side so I don't think I have a collapsed brake hose. Just not sure how to identify the MC. My truck is somewhat of a mutt. It has the cast iron reservoir though with the single hold-down hoop. I have the bigger drums with wider 2.75" shoes but can't say they were stock or not. Thanks!
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline Henry

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Re: 84 C10 Brakes
« Reply #106 on: August 05, 2018, 12:40:13 PM »
Hi 99:
Sounds as if you have a 1984 JB5 system....the master cylinder may be the same one as the JB3...I do know that the 1984 JB5 had the dual diaphragm vac unit. The 1984 service manual may have pics of what the various master cylinders looked like. You also should page back on this thread or a related thread by Ronno and see that the moderators linked some images of various master cylinders...you should also go to the tech section of this forum to get more pics of master cylinders.
Henry

Offline Ronno6

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Re: 84 C10 Brakes
« Reply #107 on: August 12, 2018, 09:06:23 PM »
From what I have seen the cast iron reservoir master cylinder was used only in the JD3 and JD5 brake systems,
which were used in diesel powered trucks.
These were hydra boost systems, and I don't know how well this MC will work with Vacuum booster......
You can lead a man to water, but yoiu can't keep him from pissing in it.