Brakes dragging

[z8987]

Very interesting that this has come up. I had asked about the newer vs the older M/C back in December and never got a definitive answer. From what you say it sounds like this has been done on your car. My guess is that you can swap the large and small reservoirs on the M/C and call it good. Of course we all have opinions.

My other series one it was suggested to swap the lines. The easiest way to do that was to take the master cylinder off and connect the lines the proper way, then turn the master cylinder slowly sound until you can get it into the booster.


Sent from my iPhone using Tapatalk

[Patcon]

I doubt the engineers reversed the reservoir locations for no reason. Not totally sure what it was,  but it costs money to retool and redesign parts. It doesn't really happen for no reason

[z8987]

Nothing comes out of the bleeder. Is this a rebuild or replace?

I don’t want to take things apart until I know where I’m going. Is this brake cylinder more current than a 1970?


Sent from my iPhone using Tapatalk

[Roberts280Z]

I've had that happen when the lines were plugged.  Usually happens at the ends of the flexible lines.  This would explain the dragging by maintaining some pressure in the slave cylinder.

Edited January 25, 2022 by Roberts280Z

[w3wilkes]

The wheel cylinder in your picture is the old series 1 style. The newer wheel cylinder isn't as tall and the brake line connects going straight in from the back rather than at an angle from the side. Check the thread I linked in post #5 of this thread for a visual comparison of the series 1 wheel cylinder and the newer cylinders.

[Zed Head]

44 minutes ago, z8987 said:

Nothing comes out of the bleeder. Is this a rebuild or replace?

Did you press on the brake pedal?  Not clear what you're doing.  Nothing should come out until you apply pressure.

 

[z8987]

I use a pressure tank at the master cylinder to simulate pressing the pedal, and yes.  That pressure bottle saved my marriage. LoL

 

The pressure differential switch has a line to each front brake and only has one line going to the back where it connects to a proportioning valve.  This makes me believe that master cylinders are marked for a reason.   All the lines are the same diameter, so that makes me think the back brakes may possibly require half the pressure?   

 

FYI - I learned that the "Differential Switch" is what the master cylinder is connected to in the engine compartment.   The proportioning valve is mounted in the back of the car and controls the the volume of brake fluid to the calipers.  

Edited January 25, 2022 by z8987

[Zed Head]

Disconnect the line at the wheel cylinder.  Use your pressure device at the master cylinder and see if fluid comes through the line.  If it does then the bleeder valve or the wheel cylinder is clogged.  If it doesn't then there's a blockage before  the wheel cylinder.

[z8987]

The last post in this thread by beermanpete explains how the master cylinder functions and why the lines from the master cylinder need to go to the proper area on the differential  switch in the engine compartment.  

 

 

 

The master cylinder for sale at zcardepot also explains what's going on. 

https://zcardepot.com/products/brake-master-cylinder-1-wilwood-240z-260z-280z

 

Edited January 25, 2022 by z8987

[Zed Head]

Thought that you were working on a rear wheel cylinder and/or stuck rear brake (Brakes dragging.), one side only.  Not clear what the subject is.

Edited January 25, 2022 by Zed Head

[z8987]

2 minutes ago, Zed Head said:

Thought that you were working on a rear wheel cylinder and/or stuck rear brake (Brakes dragging.), one side only.  Not clear what the subject is.

1. My left rear drum was stuck. I found today that no fluids come out of the brake cylinder when it's pressurized and I open the bleeder. 

2.  I also discovered that my master cylinder is not connected to the differential switch as it should be. 

 

I started tracking all of this here.  For me at this point it's the same issue.  I have noticed the front brakes dragging which can be caused by #2 above.  

 

I believe getting my master cylinder / differential switch setup properly. 

[Zed Head]

38 minutes ago, z8987 said:

the front brakes dragging which can be caused by #2 above.  

Disagree, emphatically.  But, good luck.