TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > Suspension, Steering, Brakes & Wheels
  New Posts New Posts RSS Feed - Brake master push rod
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

Brake master push rod

 Post Reply Post Reply
Author
Message
redright9 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Jun/23/2014
Location: Antelope Valley
Status: Offline
Points: 99
Post Options Post Options   Thanks (0) Thanks(0)   Quote redright9 Quote  Post ReplyReply Direct Link To This Post Topic: Brake master push rod
    Posted: Feb/19/2017 at 9:24pm
Hello,

I have a '69 440 Rambler wagon. I am installing the Scarbird disc brake conversion and purchased the brake master cylinder they recommended (Raybestos MC36386). I removed my old one and the pushrod that attaches to the pedal seems about a half inch too short and the new master cylinder doesn't have the groove for the snap ring to install the pushrod. My car is originally a non power drum brake car. What pushrod do I need? Thanks

Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19610
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Feb/20/2017 at 6:50am
You can get by without the snap ring to hold the rod in, it won't fall out unless the piston in the MC sticks in the fully depressed position and the pedal comes all the way back. Won't matter then -- you have no brakes regardless, and something drastic has gone wrong.

You might need to make a new pushrod. I've done it with a long 3/8" (I think that's the size) eye bolt years ago. If it's too long brakes will be real touchy and pedal travel short, too short and pedal will go down too far, and of course once it hits the floor you're done.

You might want to try the original pushrod. The hole in the new MC may not be as deep as the original, but you can measure that. You can judge if it goes down too far without moving the car.  If you do decide to move the car do it in as level a place as possible and make sure the park brake works. You just need to get the car moving -- pushing is fine, don't need to move fast at all. If travel seems good and brakes stop it from a slow roll it's time for a test drive.
Frank Swygert
Back to Top
redright9 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Jun/23/2014
Location: Antelope Valley
Status: Offline
Points: 99
Post Options Post Options   Thanks (0) Thanks(0)   Quote redright9 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/20/2017 at 12:09pm
Thanks for your reply! I did measure and the hole in the new master is deeper than the old one. Looks like I'm going to have to make something..
Back to Top
redright9 View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Jun/23/2014
Location: Antelope Valley
Status: Offline
Points: 99
Post Options Post Options   Thanks (0) Thanks(0)   Quote redright9 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 10:53pm
I tried remeasuring it and tried to be more accurate. Seems like it's about 0.250" difference ( deeper). I think I will try it and see how it acts. Thanks again.
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19610
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Feb/22/2017 at 6:20am
I stuck a small nut down the hole in the MC once. Fixed it right up. That or a piece of steel rod, bolt, etc. .... something that won't compress or let the rod push by and wedge in. Once you get something the right length a little epoxy or RTV in there to hold it in place won't hurt.

The deep MC is usually for non-power brakes, helps retain the pushrod if there is a failure  -- piston sticks all the way in. As noted, what good is retaining the rod then? I think the idea is you could pull the pedal back up and might be able to get a little more brake, but that takes too much time, and you have to think about it while you're in panic mode from having the pedal hit the floor and not ciome back up...
Frank Swygert
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 1.141 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or