How does the 240z/280z wheel cylinder work??

[ramsesosirus]

Just replaced the original wheel cylinders on my stock 76 280z.  The clips on the back are a pain to install.

How does this type of wheel cylinder work??

There is only one piston that pushes on one shoe, the other shoe has the stationary adjustment wheel....

Most cylinders have two pistons, pushing out on each shoe.  

I had a picture, but it won't upload it...  I don't see how both shoes will be engaged, unless the cylinder moves in the backing plate?? (doubtful).

 

The cylinders changed on the 1977 280z to the "double" piston design... 

Thanks, inquiring minds want to know

 

 

[Zed Head]

1 hour ago, ramsesosirus said:

 I don't see how both shoes will be engaged, unless the cylinder moves in the backing plate?? (doubtful).

Stop doubting.  It slides.  I tried to post a picture from the FSM but there's a problem.  Check pages BR-11 and -12.

[cbuczesk]

It slides in the backing plate. Clean the backing plate well and use some brake grease where there's metal to metal contact.

Chuck

 

[ramsesosirus]

Cool, thanks. 

I've never heard of one that does this (slides), is it common?  

I guess if it does slide back and forth, it automatically centers itself from the force.  Interesting...

Thanks

[Captain Obvious]

I'm going to go a little more conservative on the description of how they work...

The whole wheel cylinder is SUPPOSED to slide on the backing plate, and it is SUPPOSED to center itself from the force. Just like a floating caliper with one piston, these are floating cylinders with one piston. And from the lack of chatter here on the forum about rear brake problems, they seem to work well enough. However, my experience is that I always had one shoe wear faster than the other.

I think the 77-78 dual piston fixed cylinder design is way better, and if you're ever replacing rear wheel bearings, I'd take the opportunity to upgrade to the newer design.

[ramsesosirus]

57 minutes ago, Captain Obvious said:

I think the 77-78 dual piston fixed cylinder design is way better, and if you're ever replacing rear wheel bearings, I'd take the opportunity to upgrade to the newer design.

I'd agree, good thing to consider in the future.

Hmm if the cylinder is supposed to slide, why then did they have a steel brake line attached to the cylinder?  Wouldn't the hard line either: 

prevent the cylinder from moving

experience stress from the cylinder moving 

 

Sounds like I need to open up those drums again and grease the cylinder sliding area.  Those retaining clips were a real pain to install... can' t imagine how much move difficult they would be with grease all over!  

I also did my best to adjust them manually (screwdriver through drum), but the e-brake has to be pulled nearly vertical...

If the e-brake turns the adjuster every time it's used, wouldn't the adjuster be "bottomed out/fully adjusted out" quickly?? 

I'd really just be happy to get some rear braking finally!  

Thanks

[Dave WM]

the adjuster only ratchets up IF there is excessive movement of the shoes, typically due to wear. If its working right you can put the drums on pretty loose and just operating the brakes either by the e brake or pedal, the ratchet mech will take up the excessive spacing. once the shoes are adjusted, the ratchet cant tighten anymore since it requires movement of the shoes to operate.

as far as the e brake, I am guessing it just needs to be adjusted under the tunnel to take up some of the slack.

Edited August 8, 2017 by Dave WM