1940 Continental brakes question

[Rick Fraser]

Hi Guys, I've been struggling with my brakes of late. I installed a new master cylinder, bench bled, then proceeded to bleed the lines. Starting from the passenger rear. The pedal went straight to the floor. Repeated the bleeding procedure, passing about a quart of fluid thru. They were better, but not quite as good as I think they should be. Pedal travel is long, more than half way to the floor before engagement. We adjusted the adjusters to no avail. Even though they work ok; I can lock up all 4 wheels, but not completely satisfied. Do you guys think I should adjust the push rod next, or suspect the  M/C?

 

Please let me know your thoughts.

[JFranklin]

Are the drums flexing? (turned too thin).

[charlespetty]

How was the brake application before the master cylinder was replaced and when the old master cylinder was still working?  The brakes on my Continental start applying within the first 1/3 of pedal travel.  If the brakes were working fine when the old master cylinder was still functional, I would suspect the new master cylinder's function.  

[Rick Fraser]

The pedal suddenly went straight to the floor. Very shocking. Pressure came back with pumping but obviously not ideal. Had previously been working fine so I suspected the M/C. That's when I bought the new M/C

I was reading that the push rod should not be touching the piston, but should be adjusted so that the pedal travel is only about 1 to 2 inches. Does that sound right?

 

Thanks for your input.

[Rick Fraser]

Pedal went straight to the floor after sitting for 2 days. I think I will replace the M/C again. Do you guys recommend  a source? I don't want to get a garbage one again.

[charlespetty]

Chris Herrel at Boos-Herrel.  http://www.boos-herrel.com

He is the expert when it comes to 36-48 Lincolns and has always been good to me.  He has master cylinders listed in his catalog online.  

[Rick Fraser]

thanks Charles, I just called.

[19tom40]

When you bench bleed the new master cylinder, do NOT use the full stroke, just pump the first 1/2" of the stroke. The master cylinders made today can damage the seal at the far end of the stroke. After you mount and connect the master cylinder, use slow short strokes to build up pressure in the wheel cylinder before opening the bleeder screw. Try to prevent the pedal going all of the way to the floor and use slow stroke movement both ways  when bleeding.

 

After bleeding all 4 wheels, adjust the push rod by moving the pedal with your hand and listening for the click when the push rod touches the master cylinder piston. Adjust for 1/4" - 1/2" movement of the pedal before the push rod contacts the piston. I like to stay near the 1/2" limit until I have driven the car for a while. Brake fluid expands when it heats up and the longer space, allows me to determine if the fluid is getting hot enough to raise the pedal.

[Rick Fraser]

thanks Tom, this is all good advice. I'll let you know how it goes. The new M/C should be here this week.

[mobileparts]

On 4/15/2024 at 10:28 AM, Rick Fraser said:

thanks Tom, this is all good advice. I'll let you know how it goes. The new M/C should be here this week.

“ Should be here this week “ ?!?! Which is coming first —- the Egg Rolls or the Master Cylinder……

 

Come down to Spring Carlisle right now, I have three (3) made in U.S.A. on my counter —- spots I I 118 -  119….  Pick it up today, drive tonight…..

 

Craig…..

Edited April 17 by mobileparts (see edit history)