15/16 MC documentation

[rudypoochris]

I remember reading a thread that detailed step by step how to convert a 240z to the 15/16 MC. I cannot find the information now and i was wondering if anyone could link me. Thanks!

[TheNeedForZ]

Dunno if these helps at all but they are related

I searched with "15/16 master cylinder", about 3 pages of threads came up, you could search in those. If you have found the guide, please let me know.

 

http://forums.hybridz.org/showthread.php?t=93226&highlight=15%2F16+master+cylinder

 

http://forums.hybridz.org/showthread.php?t=90551&highlight=15%2F16+master+cylinder

 

http://forums.hybridz.org/showthread.php?t=89967&highlight=15%2F16+master+cylinder

 

http://forums.hybridz.org/showthread.php?t=70314

[TheNeedForZ]

Forget about the above link, but read them if you are interested.

 

I might have found what you are looking for : There is a HTML file called "Z cheat sheet" or something, I forgot where I got this originally but I suggest you go find it. Here is the section about brake upgrade installation : It says the 15/16 installation is a "direct replacement" so prolly a bolt on.

 

 

 

Toyota Upgrade From 240Dave s Page

 

***SPECIAL NOTE****

 

There are currently two new brake bleeding products available for do-it-yourselfers. They are bleed screws with check valves installed to allow brake bleeding without worrying about air entering the system when you lift the brake pedal. Russell's Speed Bleeders are one, and Earl's Solo-Bleeders are the other. You can find Russell Speed Bleeders in catalogs such as Summit, and Earl's can be found anywhere that sells Earl's merchandise. You can contact Earl's directly to find a vendor in your area.

 

 

--------------------------------------------------------------------------------

 

Option #1

Toyota 4x4 caliper and stock 240-280Z rotor

[Parts List] [Procedure]

 

Introduction

 

This upgrade improves the braking of the stock 240-280Z by increasing the clamping force of the front brakes with the use of Toyota 4 piston calipers from a Toyota 4x4 pickup and the stock solid 240-280 rotors. These calipers will bolt directly to the Z strut, with no modifications. The reason for this, is that these calipers are made by Sumitomo, a brake component manufacturer, who manufactured brake components for Nissan/Datsun and Toyota. This really works out great for us Z fanatics, since they used the same bolt pattern quite a bit, which enables us to do this swap. By using the larger front calipers, your brake torque for the front wheels is increased. Brake torque is what makes your car stop, the larger the amount of torque the quicker you can stop. There are two ways to increase brake torque. First, you can increase the clamping ability of the calipers, and secondly to increase the rotor diameter. Of course, if you do both modifications at the same time, you will substantially increase brake torque. If you take a look at any after market brakes, they are always larger in diameter than their stock counterparts for this very reason. This particular upgrade, while effective, does not address the rotor warpage issue, associated with excess heat. You can check out Option #2 if you are interested in that setup.

 

 

 

 

Parts List

 

1. (2) Calipers from a '79-'84 Toyota 4x4 pickup. They should be stamped 'S12' on the side. (new or rebuilt)

2. (1) Get a set of semi metallic pads. There are many brands, I prefer Porterfields.

3. (1) 280ZX 15/16" master cylinder (new or rebuilt)

4. (1) DOT 5 Brake fluid.

 

Not required, but recommended:

1. Stainless braided brake lines and new hard lines.

2. New rotors, possibly cross drilled if available/desired (I wouldn't use cross-drilled, but that's your choice).

3. Proportioning valve (280ZX unit works well)

 

Procedure

 

Original Equipment Removal

 

1) Remove your wheels (obviously), and safely jack up the car.

2) Disconnect the brake lines from the calipers.

3) Remove your old caliper and pad assemblies.

4) Remove the front rotors and bearings.

Now is the time to check your rotor and bearing condition. If anything is questionable, take it to a shop and

have it machined within spec, or spend a little cash and buy new parts. Although not required, I highly suggest a new set of rotors, since there is no point in doing this upgrade with old worn out rotors.

5) Remove the backing plate.

This is an optional step, since the backing plate can be retained by cutting excess metal to provide clearance for the new 4 piston calipers. However, these plates were known to retain moisture on stock Z cars, and I suggest removing them entirely. While this will create a dustier condition, the moisture problem will no longer be an issue.

6) Remove the master cylinder.

Disconnect all brake lines at the master cylinder, and remove it. You can retain the stock 240-280 brake booster. Be careful, as brake fluid is highly corrosive, and any spills should be cleaned up immediately. It is a good idea to keep some soapy water and a rag handy if you are at all concerned about your paint.

 

New Equipment Installation

 

1) Install new 15/16" 280ZX master cylinder.

This is a direct replacement for the 240-280 style. Reconnect all previously disconnected brake lines. Be careful to not over tighten, you might strip threads.

2) Install the new rotor and/or bearings/seals.

Installation is reverse of removal. Use new cotter keys and nuts as well, these are very cheap, but necessary.

3) Install new brake lines.

If you are retaining your old lines, then skip this step. Although, that would be a mistake in my opinion.

I would also install the proportioning valve at this time. Although not deemed necessary, I feel the brake upgrade is incomplete without it. The reasoning for this, is that the new 4 piston calipers have a much greater clamping force. So, the brake system becomes unfairly biased towards the front. The proportioning valve alleviates some of this phenomenon.

4) Install new 4 piston calipers.

Installation is the reverse of the stock 240Z caliper removal. These are a direct replacement, and require no special mounting. Make sure to have the brake bleed screw towards the top. You can install it the other way, but it will not function correctly. Bleed screw orientation is how you can tell the difference between the right and left calipers.

5) Re-connect all brake lines.

Installation is once again, reverse of removal. Some minor bending of the hard brake lines is necessary to get them to fit correctly. Be careful not to kink any lines, and make sure that all lines are free of obstruction or interference.

6) Install new brake pads.

7) Bleed the brakes.

Do this in whatever method you prefer, but be aware that most brake problems can be associated with improper

bleeding. If you are in question, just take it to a local shop, and have them power bleed the brakes. This isn't

expensive, and works far better than any backyard job.

[Nigel]

The 15/16 MC isn't quite a direct bolt on for early Z's like those instructions imply. Prior to 1973, the brake lines to the MC are reversed compared with the later models. You will have to rebend/make new brake lines for the connection to the MC if you have a '70 to '72 Z.

 

Nigel

'73 240ZT

[Pop N Wood]

Those directions also don't mention lengthing the push rod between the MC and booster.

 

Actually those directions are pretty worthless.

 

As for the brake lines, just make sure the hardline to the front brakes goes to the side of the MC with the larger reserivour. The hardlines on the early 240's have enough wiggle room to make it without requiring new lines. Between that and adjusting (lengthing) the push rod, it is a simple bolt in deal.

 

Arizona Z car use to have a write up on their web site many years ago. That is what I used to switch over my 1970