Brake failure

[muddy]

There used to be a help me fix this section in the old site. But anyway...

The old Plymouth is testing her luck again. Brake pedal goes to the floor. If pumped brakes work but pedal still fades and goes away.

Drove it two days like this, no fluid lost.

I've replaced the master cylinder, and bleed all air out. When engine is shut off I have a firm responsive pedal. With engine running the pedal goes to the floor and does not recover.

No leaks, even took apart rear drum brakes and all look good.... antique, but in working order lol.

It seems as if the only thing left is the booster.  Usually when they fail you get a hard unresponsive pedal and rough running. Even if it's not the booster but a vacvim leak it should still give a hard pedal?

Has anyone had a booster actually cause lack of pedal when failed?



Sent from the twisted mind of the Mudman

[goodfellow]

Are you seeing your brake fluid reservoir level decreasing over time Tim? Even a very small leak into the booster could cause the pedal to bottom out.

[vssjim]

To be sure I would make block off plugs for M/cyl and once bled try pedal again if not ok now new master maybe no good if ok now check each wheel by crimping each wheel hose one at a time until you can see a difference.

[muddy]

Are you seeing your brake fluid reservoir level decreasing over time Tim? Even a very small leak into the booster could cause the pedal to bottom out.

Drove it for two days 60 miles a day. No fluid loss.

To be sure I would make block off plugs for M/cyl and once bled try pedal again if not ok now new master maybe no good if ok now check each wheel by crimping each wheel hose one at a time until you can see a difference.

I'm going to block off the master like you said. Wouldn't be the first time I've gotten new parts that are bad.

Sent from the twisted mind of the Mudman

[Rusty]

Are you sure you have the right master cylinder? One set up for too longer rod will cause the sticking.

How many times did you bleed the system? Sometimes it takes several bleeds to get everything right.

[oldnslo]

This has all the classic signs of a master cylinder that is internally bypassing. Thus, the fade to the floor experience.

[Rusty]

By fades to the floor and don't recover. do you mean it stays on the the floor while running? If so disconnect the vacuum line from the booster and see if it recovers. If it does good chance the rod is a bit too long and holding the booster cracked open.

Or it may be as oldnslo says and just be bypass. But the staying on the floor part I'm visualizing makes the rod an option as well.

[stokester]

This has all the classic signs of a master cylinder that is internally bypassing. Thus, the fade to the floor experience.

+1

[muddy]

By fades to the floor and don't recover. do you mean it stays on the the floor while running?

No it just goes to the floor when applied and engine running and returns to the top of stroke.


So this weekend I blocked off the master cylinder, with dummy fittings. Problem went away had solid pedal eng running or not.

So I went to HF and got a vacuum bleeder. Bleed the entire system probably 10 times. Still had a mush pedal that went to floor with engine running.

So pissed I took a break and then bleed it once more. Ready to give up I decided to at least move the car and get ready to take it to the scrap yard lol.

As I was moving it around the pedal kept getting better. So I took it for a test drive....

I'm not sure if there was just a tad of air in there. But it's fixed, or at least back to normal. I mean it's a 94 Sundance it never had a beautiful pedal it great stopping distance



Sent from the twisted mind of the Mudman

[Rusty]

   A Sundance with working brakes, will miracles ever cease?

[slip knot]

  A Sundance with working brakes, will miracles ever cease?

A 27 year old Sundance still on the road

[fatfillup]

And its a hatchback no less!


Hopefully you have it sorted out and you can pass it on to Sam when he learns to drive

[DeadNutz]

The wife keeps getting on me to fix the brakes on the forklift and the tractor. I tell her as long as the hand brake works on the forklift and I can drop the bucket or box scraper on the tractor I'm fine without brakes. I actually have some left brake on the tractor but I don't even want to know what it will cost to get the wet brakes done.

[skfarmer]

For some reason all i can think of is  muddy taking up about 2/3 of the front seat and the plymouth leaning to one side. Just like me incredible in the incredibles  movie.

Careful slamming the door shut Tim!

[muddy]

  A Sundance with working brakes, will miracles ever cease?

A 27 year old Sundance still on the road

And its a hatchback no less!


Hopefully you have it sorted out and you can pass it on to Sam when he learns to drive

245,000 miles I'm keeping it alive until 300,000 then what happens after that is in the car gods hands 

For some reason all i can think of is  muddy taking up about 2/3 of the front seat and the plymouth leaning to one side. Just like me incredible in the incredibles  movie.

Careful slamming the door shut Tim!

Your not far off. Remember High Tower from Police Academy?! When he ripped the front seat out and sat in the back! 

A couple months ago I went to shut the door and the arm rest came off in my hands! 

Sent from the twisted mind of the Mudman