Converting to rear disc

[vdubbles24]

Replacing all brakes. Factory replacement on front and converting rear to disc using beebani brackets and Isuzu hardware.

 

No I need to upgrade my master as well?

[flatcat19]

Switch to a master from a Z, 80 or earlier, of a car that was 4 wheel discs.

 

Z's went 4 wheel disc in 77? 80-81 is the last vertical mounting master(15/16") available.

[datzenmike]

The Z24 powered 720 should have a 15/16" master in it. But it will have drum residual valves in it for the rears. I would just pull the front residual valve from another Datsun with disc brakes and put in the rear position. Now it's converted to 4 wheel disc brake.

 

Keith the '79 zx was the first rear disc z car but it's the '82-'83 that has the nicercalipers. The '79-'81's looked like the fronts on the 620.

[flatcat19]

That is irrelevant. Disc/disc valving is just that. The 82 and 83 brake master cylinder had horizontal mounting tabs.

 

Given this is a 720, I am clueless as to how the master cylinder bolts on.

[datzenmike]

What's irrelevant? That a 720 has a 15/16" master or that it needs the rear residual valves replaced with disc brake residual valves if converting to 4 wheel disc?

 

I never mentioned the '82-'83 masters only that the '82-'83 rear calipers were nicer than the early zx ones.

 

 

Pretty sure the 720 masters are horizontal mount bolts or we'd all be using them. I wonder if a 720 15/16" rebuild kit would work on a zx master?

[flatcat19]

No. The irrelevance was the style of calipers between the two.

[datzenmike]

If you saw them I guarantee you would pick the '82-'83 all things equal.

 

 

 

 

.

[flatcat19]

Still makes no difference to OPs situation as he's using Bee brackets.

 

Question was about master cylinders.

[datzenmike]

I only assume that either ZX caper will fit BEEBANI's bracket... What does the BEEBANI bracket require for a caliper?

[iceman510]

Isuzu hardware.

 

Maybe this describes the calipers he is using?

[flatcat19]

Rear for bee kits is the Izusu stuff. Hardbody for the fronts.

[vdubbles24]

Calipers and rotors off a 1989 Isuzu trooper

[Charlie69]

The 720 Master is a horzontal Master and Mike is stating to pull the the rear drum brake residual valve out of the 720 master and replace them with disk brake reidual valves instead of buying a complete master cylinder.  Simple fix.  The 720 Master is already better than the Z

 

The 82/83 280ZX Master Cylinder lines connect to the bottom of the master cylinder and the 83 720 connects to the drivers side on a US vehicle.

[Spiff]

BUT! What do people do for E-brake with this setup?? That's what I wanna know, cause I haven't found a single post about what people are doing for handbrake with this setup(I need that to stay legal over here)

[datzenmike]

I have a set of Altima rear discs (not installed) and they have brake cables for the e brake. This is why I grabbed them. I think I could connect to my hand brake.

 

 

Others had a smaller drum brake inside the rotor with brake shoes. Pathfinder has this set up.

[flatcat19]

Hydraulic line lock.

[datzenmike]

Assuming you never have a leak and live on a slope and depend heavily on an e brake. I guess it would work but does any car maker trust this enough to use it? You just have to pump the brake and have an inline solenoid to hold the pressure in the rear line. Or perhaps both front and rear systems? Actually a pretty good idea except that an e brake must work independently from the main hydraulic brake.

 

Back in the day of drag racing there were Hurst Line Locks. Pump up the brakes and with a switch and solenoid you could lock the front wheels to prevent forward creep through the staging lights.

[flatcat19]

There are hydraulic bypass e-brake levers/slave cylinders.

 

 

Covers what you'd need. The reliability is only as good as your brake parts.

 

 

There are lots of e-brake options. OP just looks a bit too lazy to answer his own questions.

 

 

 

 

I'm all out of spoons.

[Charlie69]

Wait until Mike Klotz designs a rear disc brake setup.  He will do a complete package with E-barke setup.  Might not be in my lifetime!  LOL

[Spiff]

The Isuzu setup has a lever on the brake caliper. I thought about line lock, but I wouldn't trust it, all it takes is a tiny little leak and also the brake calipers aren't designed to be pressurized for hours, maybe days on end...

I see a few different universal handbrake cables for sale on summit racing, so I might just get those if I can't get anything else to work.

[datzenmike]

Again, some have a parking brake cable, some a pull rod linkage and some have a small drum brake incorporated in the rotor.

[Figbuck]

I hope you got your rear discs figured out by now. I have been driving with the Beebani rear disc set-up now for almost two years. I have abused the fock outta my brakes towing heavy leads, blasting the back roads and nasty stop and go freeway traffic at any speeds.

I don't know how this relates to the OPs specific query... but, I'm running my stock brake booster. There is a distinct two part feeling to the pedal... the fronts work first and then towards the bottom of the travel there is a big springy cushion felling when the backs come on. So far I have only locked my brakes up once in a total panic! It's a pretty hard thing to do. When it happened I thought to myself... oh shit, I'm a passenger... but the truck stopped so freakin' fast.

As far as hooking up the Izusu parking brakes to the hand brake yoke... there could be a bunch of different slick, quick and easy solutions to this.

 

Here are the Figbuck 620 oics...

[Charlie69]

What's irrelevant? That a 720 has a 15/16" master or that it needs the rear residual valves replaced with disc brake residual valves if converting to 4 wheel disc?

 

I never mentioned the '82-'83 masters only that the '82-'83 rear calipers were nicer than the early zx ones.

 

 

Pretty sure the 720 masters are horizontal mount bolts or we'd all be using them. I wonder if a 720 15/16" rebuild kit would work on a zx master?

Mike you are correct on the 720 master having horizontal mounts.  Every time you mention rear drum brake residual vales being changed to disc brake residual valves for 4 wheel disc brakes you get the same rederick.  I do not think most people understand that these can be changed and the ones that do unerstand they can be changed have no idea as to how to change them.  Maybe if you did a pictorial write up on changing the residual valves then you could just refer them to the write up.  Maybe pin the write up to the brakes section of Ratsun.  Just a suggestion.  I have gotten rid of all my spare master cylinders or I would do one.

 

Cleanining out all my parts stock so when the time comes less for my family members to liquidate.

[flatcat19]

Wilwood offers remote residual valves.

 

Ex: disc/disc master- drum brakes rear...install their 10lb. res. valve before the rear circuit. When you swap to discs, install their 2lb. valve.

 

 

There are a lot of scenarios where you can tweak your hydraulics using these. They're pretty neat.

 

Study the system enough and completely pass on those hokey adjustable proportion valve.

[BEEBANI]

Spiff,

 

If you mount the calipers towards the front, the stock cables will reach. I’m working on a new bracket at the caliper to line the cable up better. You’ll need a clamp on Clevis on the cable to attach to the lever arm.