The Ford Barn

Trelpdx · 05-21-2010, 02:36 PM

Guys,

Can someone tell me what the throw distance is on a 39 master cylinder?

Assume avaerage brake adjustment.

TX,
Peder

G.M. · 05-21-2010, 04:17 PM

I never measured the "stroke" but when it returns the back of the piston has to clear the small hole you can see down in the bottom or the brakes hang up. G.M.

CWPASADENA · 05-22-2010, 06:50 PM

I think the full stroke on a '39 Master Cyl is one inch. I should think that the brakes should be full on (panic stop) at no more then 2/3 (pedal) stroke. If you are dealing with new brakes, you may have to fully get them beded in before you can get the proper adjustment.

What is your application? If you are having trouble getting proper adjustment and you are dealing with a non-stock application and not a stock '39-'48 Ford or Merc., you may have to re-visit your installation. There is a lot involved with proper lever lingths and linkage with a "custom" brake installation.

Let us know what you are dealing with.

Chris.

Trelpdx · 05-23-2010, 12:26 AM

I'm doing a hyraulic conversion on a 35 coupe using a 39 master cylinder. I think that I have it pretty much figured out but needed the throw distance to set up the lever arm that will be pushing on the MC. The 1" helps.
Thanks much,
Peder

V8 Bob · 05-23-2010, 04:36 AM

Quote:

Originally Posted by Trelpdx

I'm doing a hyraulic conversion on a 35 coupe using a 39 master cylinder. I think that I have it pretty much figured out but needed the throw distance to set up the lever arm that will be pushing on the MC. The 1" helps.
Thanks much,
Peder

Why don't you just measure the stroke on the '39 master? Then you will know for sure before trying to set up pedal linkage.

G.M. · 05-23-2010, 08:59 AM

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Push the push rod in on the new cylinder until it touches the piston and measure the length from the mounting face to the end of the push rod. Push the piston in with the push rod looking down in the fill hole at the bottom behind the piston, continue moving the piston forward until you see the small hole that is less then 1/16" in the bottom of the cylinder behind the piston and measure the rod again. The distance between the two measurements is the stroke. This will put you in adjustment range. G.M.

05-21-2010, 02:36 PM	#1
Trelpdx Senior Member Join Date: May 2010 Location: Portland, Oregon Posts: 173	39 Master Cylinder Throw ? Guys, Can someone tell me what the throw distance is on a 39 master cylinder? Assume avaerage brake adjustment. TX, Peder

05-21-2010, 04:17 PM	#2
G.M. Senior Member Join Date: May 2010 Location: Florida and Penna. Posts: 4,471	Re: 39 Master Cylinder Throw ? I never measured the "stroke" but when it returns the back of the piston has to clear the small hole you can see down in the bottom or the brakes hang up. G.M. __________________ www.fordcollector.com

05-22-2010, 06:50 PM	#3
CWPASADENA Senior Member Join Date: May 2010 Location: PASADENA, CA Posts: 1,891	Re: 39 Master Cylinder Throw ? I think the full stroke on a '39 Master Cyl is one inch. I should think that the brakes should be full on (panic stop) at no more then 2/3 (pedal) stroke. If you are dealing with new brakes, you may have to fully get them beded in before you can get the proper adjustment. What is your application? If you are having trouble getting proper adjustment and you are dealing with a non-stock application and not a stock '39-'48 Ford or Merc., you may have to re-visit your installation. There is a lot involved with proper lever lingths and linkage with a "custom" brake installation. Let us know what you are dealing with. Chris. Last edited by CWPASADENA; 05-22-2010 at 06:53 PM. Reason: CLARIFICATION

05-23-2010, 12:26 AM	#4
Trelpdx Senior Member Join Date: May 2010 Location: Portland, Oregon Posts: 173	Re: 39 Master Cylinder Throw ? I'm doing a hyraulic conversion on a 35 coupe using a 39 master cylinder. I think that I have it pretty much figured out but needed the throw distance to set up the lever arm that will be pushing on the MC. The 1" helps. Thanks much, Peder

05-23-2010, 08:59 AM	#6
G.M. Senior Member Join Date: May 2010 Location: Florida and Penna. Posts: 4,471	Re: 39 Master Cylinder Throw ? Sponsored Links (Register now to hide all advertisements) Push the push rod in on the new cylinder until it touches the piston and measure the length from the mounting face to the end of the push rod. Push the piston in with the push rod looking down in the fill hole at the bottom behind the piston, continue moving the piston forward until you see the small hole that is less then 1/16" in the bottom of the cylinder behind the piston and measure the rod again. The distance between the two measurements is the stroke. This will put you in adjustment range. G.M. __________________ www.fordcollector.com