280ZX Brake Master Cylinder Source

[rfenwick]

I just acquired a '77 620 King Cab and am tackling a front disc brake swap.  I'm looking for what seems to be the preferred master cylinder from a '79-'81 280ZX.  Online and local stores seem to either have rebuilt without reservoirs or new very expensive $200+ parts.  Any recommendations?

[ggzilla]

Get the cheap one, then swap your reservoirs onto it

[Zeusimo]

Rockauto

Got OEM Nabco 15/16 For $31

[ggzilla]

Get the cheap one, then swap your reservoirs onto it

 

Or buy a quality master from Nissan.

[rfenwick]

Thanks for the suggestions but the fine print at Rockauto says Return and Rebuild of my part only.  Nissan part is obviously a solution albeit at $247.81

[datzenmike]

The only problem left is the residual valve in the front of the master for the rear wheels. The zx had 4 wheel disc brakes, your 620 has drums. Easy enough fix, just remove your residual valve and swap it into the zx master.

 

It's the large 'nut' that the rear brake line screws into. The residual valve in just inside it. Don't mix them up, they all look the same...

 

The residual valve traps a small amount of pressure in the lines of the brake system. Drum brakes need about 5-8 PSI to keep the shoes close to the drum and ready to act right away. Disc brakes have pads that ride right against the rotors so only a few pounds is enough to keep the rotors clean.

 

A disc brake residual valve on a drum brake will feel mushy and you won't be able to fix by adjusting the drums. On the other hand a drum brake residual valve on disc brakes will rub the pads excessively. If they don't run too hot they will simply wear out sooner.

[rfenwick]

Thanks datenmike, makes sense.  Despite all my reading on the swap, I hadn't run across this useful bit of information.  I ended up finding a complete assy at the local old school parts store for $140 and will be doing the swap next week.

[KlassicMotion]

Just info for the next guy that is looking:

 

Since I couldn't find an affordable early style '79-81 280zx master cylinder;

I bought the later '82-83 280zx 15/16" master cylinder from the parts store, and the one I got was the earlier vertical mount MC with a horizontal adapter.  Remove the adapter (glued on), and away you go.   Just check it to see, before you pay for it.

 

You can get reproduction 510 reservoirs off eBay from Mexico....  I bought one or two, they would work fine if you have a broken one that needs replaced.  I ended up cleaning my old ones and using them instead.

 

I've done what Mike suggested with the bleed-off valve.  It's definitely necessary if running rear drums, and it's easy to do.

[jay123]

Sweet tip.

Thanx Mike..

[jrock4224]

this is soloid