Yes, those holes are factory. The master cylinders on the pre-'59 trucks are vented. If you have to keep pumping up the brakes, you're probably looking at rebuilding the master cylinder and wheel cylinders.
Something as simple as a brake adjustment will cure a low pedal occasionally. You have to move too much fluid to get the brake shoes into contact with the drums with one pedal stroke if the brakes are badly worn or way out of adjustment. Once the pedal comes up, is it firm, or spongy-feeling?
"The pedal went clear to the floor and just stayed- - right- - -there- - -on the floor- - - -he said it was sorta like steppin' on a plum!" C.W. McCall- - -"Wolf Creek Pass"
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The only problem the holes in the cap would cause would be if they were clogged. Modern caps have bladders which move downward as fluid leaks slowly from the system over time, while still preventing atmospheric moisture from entering the system though the cap. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
..if it pumps up I'd say it has air in the lines. If its a firm pedal and then slowly sinks to the floor that's a good indication the fluid is by passing the cups in the M/C and is time for a rebuild. Did you bleed them good?
Yes bled the crap out of them like 10 times. .. same thing. Pumps up really nice and pedal is firm.. then sink! Got to be master cylinder huh? . Your right up the road from me. ..I live in Anderson, SC
Hmmm, sounds like it is a master cylinder. They are re-buildable so don't be afraid to tackle it. Bring it over to my place and we'll hone/rebuild and go eat BBQ.
Give me shout if your ever heading this way.(I get to Greenville quite often)
A bad master cylinder commonly feels firm if heavy pressure is put on the pedal, but sinks to the floor with light pedal pressure. Is that what you are experiencing?
If i keep pumping the pedal it gets really stiff....then after i let it sit a few minutes and go back to it it go straight to the floor. Ive got a rebuild kit on the way
