Original brakes

[JPP]

I have installed new master cylinder, all brake cylinders and brake lines, pedal is still gummy and goes to floor. No leaks present and reservoir full of fluid. Any ideas or are these  brakes just a terrible design?  Thanks

[59bisquik]

I am guessing you bled the master cylinder first and then the rest of the system. The next question, did you adjust all the shoes? If they are not adjusted and all the way retracted the pedal can go all the way to the floor.

[Dodgeb4ya]

Lockheed Brakes are a great design..........  and work well when properly re-done as per the factory instructions.

[P15-D24]

If you pump the pedal does it come up and appear firm? Then you need to bleed the brakes.  (After you release them the pedal goes down until you pump them again? Again, bleed the brakes.

Or is the pedal low but always firm? Then you need to adjust the shoes. 

[Jerry Roberts]

Sometimes there is a very small leak at a fitting that doesn't show up well . 

[Geekay]

5 hours ago, JPP said:

I have installed new master cylinder, all brake cylinders and brake lines, pedal is still gummy and goes to floor. No leaks present and reservoir full of fluid. Any ideas or are these  brakes just a terrible design?  Thanks

I recently did the same on my Fargo 1953 Suburban. Had the local break guy, who rebuilt them for me, do the final tightening up and bleed (he is very familiar with these Dodge brakes).

No problem at all with pedal and they worked well.

He did spend about an hour on going around each wheel making sure they were bled.

It does not take much to get a leak.

 

[wallytoo]

8 hours ago, P15-D24 said:

If you pump the pedal does it come up and appear firm? Then you need to bleed the brakes.  (After you release them the pedal goes down until you pump them again? Again, bleed the brakes.

Or is the pedal low but always firm? Then you need to adjust the shoes. 

close, but not always.  it is possible to have the system properly bled without a firm pedal.  that is another symptom of too much shoe clearance.  the test is two quick pumps.  first shows no firmness, second is solid pedal at the top.

 

wally

[lonejacklarry]

It is also possible that the new or rebuilt master cylilnder is bad and the piston is leaking around the seal.  You did bench bleed it before you installed it?