1966 300 convertible help!!

Big_John

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Some sort of notched ruler?
I'm thinking it has to be more accurate than that.

You've got a range of .005" and the standard ratio of gauge accuracy should be 4:1, meaning the gauge needs to be .001" accurate. That's what I would do if I was designing a gauge for industrial use. I think this doesn't need to be quite as accurate as that (to keep costs down for a one or two use tool) but it does need to at least be repeatable so you can vary the setting if need be.

A go/no-go gauge might be ideal in some ways. That would be easy to make, and pretty simple to use. Possibly a better solution would be a digital gauge where you can set it and then maybe tweak the settings to fit the MC. I do believe that there are some differences in MC piston depth that we might need to start looking at as we have more offshore sourced parts.

I do have an idea that might work... Gotta think a little more and possibly do a prototype....
 

rrmotorsports

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WOT440

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I had issues with my brake pedal, having too much play and not engaging quick enough. I adjusted the push rod to have approx 3/32" preload when tightening the MC.
Seems to work as it should with minimum free play in the pedal, maybe 3/16" total.
 
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66chry300

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Hi guys! Another update! I adjusted the rod on the brake booster with the tool and now it’s in the right spot. Still having issues with too much pressure going to the back brakes so what I am going to do is that i’m going to add an inline adjustable proportioning valve so I can meter the pressure going to the back brakes. Do y’all think this is a good idea?
Thanks!
Sean
 

Richard Reau

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I'm happy with my world just the way it is, thank you. Stubbs can kiss my ***. He's a jerk. He's about as funny as don Rickles, who also was a prick.
 

Ross Wooldridge

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Hi guys! Another update! I adjusted the rod on the brake booster with the tool and now it’s in the right spot. Still having issues with too much pressure going to the back brakes so what I am going to do is that i’m going to add an inline adjustable proportioning valve so I can meter the pressure going to the back brakes. Do y’all think this is a good idea?
Thanks!
Sean
Sean, there were some indications in some of the responses above that the master cylinder plumbing was perhaps hooked up backwards to the distribution block in some way, and that the adjusters were possibly on backwards as well on the rear brakes. I would definitely look into that before going to the trouble and extra cost of adding an adjustable proportioning valve. Rule out these things first would be my advice.
 

Clover

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Think I figured out the issue! Turns out this isn’t the original booster and it’s actually for a 66 Chrysler with disc brakes! Just going to convert it back to a single line since it’s near impossible to find the correct booster.

View attachment 564407

View attachment 564408
No. That is not a disc brake booster. It looks just like the original on my ‘66 300, which was originally drum/drum and has been in the family since 1978.
 

Clover

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Hmmm... you already have the correct master for the MUCH SAFER dual circuit system.

Look harder for a drum booster - but FIRST, correct the plumbing issues described with the routing, check the flex hoses front and rear (they can fail internally), check the shoe adjustments, and see if that booster doesn't work just fine before trying to replace it. You might find that you're brakes start working splendidly!

While I do not have any experience of using a disc booster on a drum system system, I have heard it works OK. There's no reason why it shouldn't work - it just might be a bit touchier, which is something you can get used to. On the other hand it just might be overboosted and call overboosted and cause other problems. It's worth a shot to find out... fix the other issues first.
I have put disc booster on drum system and what happens is that it works great, with further-reduced pedal effort.
 
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