The Ford Barn

Lawson Cox · 07-22-2014, 09:03 AM

A new buddy has a problem with hydraulics on a 36. He has brakes, but only when the pedal gets about 3 inches from floor, or less. Shoes are adjusted properly. Brake and clutch pedal are positioned correctly, Will a longer adjusting rod give him more pedal? I flunked arithmetic and all other higher math courses. LOL

Andy · 07-22-2014, 09:37 AM

The push rod should be right at the M/C piston but not pushing on it. If it is pushing on it even a little, the M/C will not vent and will build up pressure.
He may need to lengthen the arm that was added to the bottom of the brake pedal to get more travel. He may need a M/C with a bigger bore to move more fluid. He needs to see if his linkage is right for the cylinder he has. I push them all the way in and measure the stroke. I depress the pedal to see if I can get that much stroke.

Ken/Alabama · 07-22-2014, 10:15 AM

I think it has a lot to do with achieving the correct pedal ratio. Like how long or short the Clevis is and where it is positioned to the pedal. And what Andy said.

51 MERC-CT · 07-22-2014, 12:23 PM

The question is when the brake pedal is 3" from the floor, where is the master cyl. piston?
If the piston has moved significantly then the problem is not the length of the rod but more likely to be problems with brake shoe adjustment or bleeding problems.

Terry,OH · 07-23-2014, 06:04 AM

Do the shoes have full contact with the drums. adjust the front shoe up until there is slight drag and then the rear, slight drag. If this increases the pedal height some of the problem is the arc of the shoes do not match the drums. You can run the shoes with slight drag they will slowly arc themselves in if they are a close fit to start.
Andy is correct about the adjustment of the MC actuating rod. So changing to a longer rod is not the answer, the correct final adjustment is.

George/Maine · 07-23-2014, 06:15 AM

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Do you still have 39 master cylinder 1 line stock pedal. or have dual line MC.

07-22-2014, 09:03 AM	#1
Lawson Cox Senior Member Join Date: May 2010 Location: Above the gnat line in Georgia Posts: 7,082	Dumb question about brake cylinder push rod A new buddy has a problem with hydraulics on a 36. He has brakes, but only when the pedal gets about 3 inches from floor, or less. Shoes are adjusted properly. Brake and clutch pedal are positioned correctly, Will a longer adjusting rod give him more pedal? I flunked arithmetic and all other higher math courses. LOL __________________ Life is like a roll of toilet paper. The closer to the end, the faster it goes. It is better to be seen, than viewed. "We sleep safe in our beds because rough men stand ready in the night to visit violence on those who would do us harm".

07-22-2014, 09:37 AM	#2
Andy Senior Member Join Date: May 2010 Location: Kerrville, Tx Posts: 2,879	Re: Dumb question about brake cylinder push rod The push rod should be right at the M/C piston but not pushing on it. If it is pushing on it even a little, the M/C will not vent and will build up pressure. He may need to lengthen the arm that was added to the bottom of the brake pedal to get more travel. He may need a M/C with a bigger bore to move more fluid. He needs to see if his linkage is right for the cylinder he has. I push them all the way in and measure the stroke. I depress the pedal to see if I can get that much stroke.

07-22-2014, 10:15 AM	#3
Ken/Alabama Senior Member Join Date: May 2010 Location: Alabama Posts: 3,395	Re: Dumb question about brake cylinder push rod I think it has a lot to do with achieving the correct pedal ratio. Like how long or short the Clevis is and where it is positioned to the pedal. And what Andy said.

07-22-2014, 12:23 PM	#4
51 MERC-CT Senior Member Join Date: May 2010 Location: East Hartford, Ct Posts: 5,898	Re: Dumb question about brake cylinder push rod The question is when the brake pedal is 3" from the floor, where is the master cyl. piston? If the piston has moved significantly then the problem is not the length of the rod but more likely to be problems with brake shoe adjustment or bleeding problems. __________________ DON'T RECALL DOING SOMETHING FOR MYSELF BASED ON SOMEONE ELSE'S LIKES OR DISLIKES

07-23-2014, 06:04 AM	#5
Terry,OH Senior Member Join Date: May 2010 Posts: 5,187	Re: Dumb question about brake cylinder push rod Do the shoes have full contact with the drums. adjust the front shoe up until there is slight drag and then the rear, slight drag. If this increases the pedal height some of the problem is the arc of the shoes do not match the drums. You can run the shoes with slight drag they will slowly arc themselves in if they are a close fit to start. Andy is correct about the adjustment of the MC actuating rod. So changing to a longer rod is not the answer, the correct final adjustment is.

07-23-2014, 06:15 AM	#6
George/Maine Senior Member Join Date: May 2010 Location: Mid coast Maine Posts: 1,878	Re: Dumb question about brake cylinder push rod Sponsored Links (Register now to hide all advertisements) Do you still have 39 master cylinder 1 line stock pedal. or have dual line MC.