Hi.

i have a 1977 Plymouth Fury Sport. Long story short im at my wits end with the brakes. Ive replaced all brake lines/hoses it has recon callipers on the front and when i bleed them no air comes out but plenty of fluid does yet the pedal goes to the floor when i press it and right at the last point it applies the smallest amount of pressure to the front wheels. If i block the front outlet from the master cylinder the pedal is solid and the backs lock up perfectly but as soon as the front is reconnected it goes to the floor again. I tried a new proportion valve and have tried a direct feed off a splitter to both fronts and its the same each time. Tried a different master cyclinder which is meant to be near new and it’s exactly the same. Any suggestions?

 

If I'm reading this correctly, you said you blocked the front outlet, and the rears work ok? You said you changed the lines too. It sounds like you have the lines reversed. The front outlet feeds the rear brakes. Is that how you have it hooked up?

 

Hi thanks for replying. Yes the rear brake line is connected to the furthest port on the master cylinder from the bulk head/servo (smaller section when looking inside the master without the cap on) and the fronts are connected, or was connected to the port closest to the bulk
head/servo (much larger section inside the master)

when the front are connected ive hose clamped each side and it makes no difference pedal goes to the floor still. The only time i ever get a solid pedal is when i block the port on the master cylinder where the feed for the front brakes goes.

could it be an unlucky situation where i have 2 faulty master cylinders as when the fronts are connected i do get fluid out the bleed nipples on the front calipers but its like it cant hold the pressure but there is no leaks anywhere

 

Gotcha! Next step and we'll get this fixed. I ran into a similar problem where the brake pedal (in the car) needs to come up all the way in order to allow the master cylinder to open (gather fluid) and then push that fluid forward. Try pulling up by hand, let it sit for a second or two and see if that does it. If it does you know you have a binding inside pedal. You could also disconnect the pedal pushrod and see if it's binding. Step 2 double check the master cylinder is the one for a caliper system. It should be seeing it's a 77. And yes, you very much could have another bad master. Good luck.

 

Im hoping i have just figured out the issue. The callipers are on the wrong sides. The code i took from the drivers side (left side) says its for the passengers side (right side) which would make
sense as the bleed nipple is lower than the highest point of the calliper trapping air so im hoping if i swap them over i will get all the air out the system and get a pedal! Will do this in the next couple of days and fingers crossed get a result

 

Ah hah moment!! I'd say you figured it out. I'm sure that'll do it. Good luck!