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milesz

Brake booster and Master cylinder upgrade

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I have a 73 240z with a v8 and need to upgrade my braking system. I have already upgraded to the Toyota 4x4 front brakes and now need to upgrade booster and MC. I have researched here and other sites and kind of confused. I also have a booster from a 79 280zx but will not fit right (to big and wont mate up with the firewall)and has a soft pedel.

 

Any advice will be welcome, thanks in advance.

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Yeah that's a 15/16" Master cylinder... I found that it's no longer available or if you're able to find one it is close to $200

Almost any auto parts store has those 15/16" MC for less than $50. I got mine at Oreily's.

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Almost any auto parts store has those 15/16" MC for less than $50. I got mine at Oreily's.

 

I think he meant new, non the reman crap sold at the chain stores. I have never had good luck with any reman master cylinder for any of the various cars I've owned, especially when they are aluminum.

 

Find a new one and save yourself a headache later.

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New ones are hard to find and expensive if you can find one. Rebuilds as of 2 weeks ago are no longer available as well. I spent 3 whole days calling every parts distributor. I started to get a few leads but decided it wasn't worth my time.

 

I now have a 76 2+2 booster and a 1" Wilwood master cylinder. Works great IMHO

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$35 at Autozone. If it is bad rebuild it your self. Not hard to do. Sure beats paying two bills for a new one.

 

http://www.autozone.com/autozone/parts/1979-Nissan-Datsun-280ZX/Master-Cylinder-Brake-System/_/N-imgvtZ8kn47

 

When you put this on your car you will need to swap the front and rear lines front to back. The 240 MC is swapped from the ZX one. There is enough slack in the stock lines to do it.

 

As for booster, I installed an 8.5" booster in my 70 240z. The larger ZX ones won't clear the clutch MC. I had to drill new holes in the firewall, I think 10 mm farther out. I have the same brakes as you, works fine.

 

The attached file has a bunch of notes and part numbers I collected about boosters and MC's. There is a 1" option out there.

Z car brake boosters.doc

Edited by zdlite

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$35 at Autozone. If it is bad rebuild it your self. Not hard to do. Sure beats paying two bills for a new one.

 

http://www.autozone...._/N-imgvtZ8kn47

 

When you put this on your car you will need to swap the front and rear lines front to back. The 240 MC is swapped from the ZX one. There is enough slack in the stock lines to do it.

 

As for booster, I installed an 8.5" booster in my 70 240z. The larger ZX ones won't clear the clutch MC. I had to drill new holes in the firewall, I think 10 mm farther out. I have the same brakes as you, works fine.

 

The attached file has a bunch of notes and part numbers I collected about boosters and MC's. There is a 1" option out there.

 

Trust me - I tried it via Autozone 3 times (and 3 other places) - they have it cross referenced wrong - you'll get a 15/16" master from them, but it has the wrong horizontal bolt pattern, the wrong reservoirs, and the bleeders are different - It won't work... They tried ordering it 3 different times for me... finally gave up - They finally called the distributor and got the same answer you'll get wherever else you call - no longer available send in your current MS for a rebuild... Hard to do if you don't have one to start with! LOL

 

I'd be surprised if all of a sudden there's availability again - they all get them from the same few distributors for the most part

 

It would be great if they were available - I would definitely buy one as a backup so keep us posted - would be great news

 

 

 

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Trust me - I tried it via Autozone 3 times (and 3 other places) - they have it cross referenced wrong - you'll get a 15/16" master from them, but it has the wrong horizontal bolt pattern, the wrong reservoirs, and the bleeders are different - It won't work... They tried ordering it 3 different times for me... finally gave up - They finally called the distributor and got the same answer you'll get wherever else you call - no longer available send in your current MS for a rebuild... Hard to do if you don't have one to start with! LOL

 

I'd be surprised if all of a sudden there's availability again - they all get them from the same few distributors for the most part

 

It would be great if they were available - I would definitely buy one as a backup so keep us posted - would be great news

 

Lastly, what do you guys think about using the 240z booster with a 280zx MC? Is this a good combo?

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Lastly, what do you guys think about using the 240z booster with a 280zx MC? Is this a good combo?

 

The 79 280ZX MC has the correct bolt pattern for the 240Z booster. I have used this set up for eight years with no problems. Stops fine with the Modern Motorsports Toyota 4x4 calipers up front and 240sx calipers in the rear. Unless you have an automatic 240Z, it is difficult to mount a larger booster because the clutch MC is in the way.

 

Note if you use the 280ZX MC you will have to adjust the push rod that comes out of the booster to be a little longer or you will have too much brake travel and your car will not stop very well. But don't screw the push rod out too far or you will lock the brakes. See brake section for details.

 

You can adjust the push rod on the car by unbolting the MC, leaving the lines hooked up, by removing the nuts holding the MC to the booster and then pulling the MC away from the booster to access the push rod adjustment. Adjust the push rod out in small increments, bolt the MC back on and test drive the car after each incremental adjustment to the push rod.

 

If the brakes lock up you will need a 10mm wrench to open the MC bleed screws to relieve the hydraulic pressure that has accumulted in the hydraulic system. Of course you will need to back off the push rod lenth just a bit if you lock the brakes.

 

Took me three tries to get the optimum push rod length and yes I did adjust the push rod out a bit too far once and had to open the the bleed screws on the MC to get back home. No big deal.

 

There are some good threads in the brake section that explain the push rod adjustment. One of the threads has a drawing showing the relative positions of the 240Z and 280ZX push rod lengths. You can use the indicated length as a starting point.

 

Note be careful not to pull the push rod out too far and drop the reaction disk inside the booster. The brakes will never be right if that disk is missing. See FAQ sticky for the discussion on lost reaction disks.

Edited by Miles

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Trust me - I tried it via Autozone 3 times (and 3 other places) - they have it cross referenced wrong - you'll get a 15/16" master from them, but it has the wrong horizontal bolt pattern, the wrong reservoirs, and the bleeders are different - It won't work... They tried ordering it 3 different times for me... finally gave up - They finally called the distributor and got the same answer you'll get wherever else you call - no longer available send in your current MS for a rebuild... Hard to do if you don't have one to start with! LOL

 

I'd be surprised if all of a sudden there's availability again - they all get them from the same few distributors for the most part

 

It would be great if they were available - I would definitely buy one as a backup so keep us posted - would be great news

 

 

I just ordered a new brake master cylinder for a 1980 280ZX from Black Dragon. They told me it is on back order but still available at $139.95

Edited by alainburon

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I just ordered a new brake master cylinder for a 1980 280ZX from Black Dragon. They told me it is on back order but still available at $139.95

 

I installed this Wilwood unit - It was $100 via Jegs and immediately available - Summit was on back order but probably have them now...

 

It's a 50/50 split... the only thing you'll have to do is widen the mounting holes slightly with a file (5 minute job) and it will bolt on directly... I also had to remake the small brake lines that go to the prop valve - the ones that go off the bottom of the MC to the prop vales that are around 8 inches long - they are standard thread on the MC and your line is metric thread... I'd bet a call to Wilwood would yield an easier way to address that - I'd bet they have the metric fitting for the bottom which would make it a easy bolt on... I'm using this MC with the 10 inch 1976 280z 2+2 booster - that was also a direct bolt in to my 75 280z - You have to lengthen the actuation rod in the booster slightly too - all easy stuff.

 

260-8794-lg.jpg

http://www.wilwood.com/Images/MasterCylinders/Master%20Cylinder%20Photos-Large/260-8794-lg.jpg

260-8794-lg.jpg

260-8794-lg.jpg

 

260-8794-lg.jpg

Edited by kj280z

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New ones are hard to find and expensive if you can find one. Rebuilds as of 2 weeks ago are no longer available as well. I spent 3 whole days calling every parts distributor. I started to get a few leads but decided it wasn't worth my time.

 

I now have a 76 2+2 booster and a 1" Wilwood master cylinder. Works great IMHO

 

What is the part number for the wilwood master cylinder?

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Wilwood p/n: 260 -8794

 

Available at Summit WIL-260-8794

 

The 280ZX master cylinder is now extinct.

 

Here is what other HybridZ members have done:

 

I just completed the Wilwood master cylinder and 280Z booster swap. Works well with my Modern Motorsports Toyota vented front and 240SX rear disk brake set up. Much better than my old stock 240Z booster and 280ZX master cylinder.

 

The mounting holes in the Wilwood mounting flange have to be filed to match the slightly wider Datsun bolt pattern. I used a dremmel with a rotary file to open the top and bottom holes.

 

No need to make or buy new brake pipes or adaptor fittings. The Wilwood master cylinder outlet ports are 3/8 - 24. To mate the Datsun 10mm x 1.0 brake fittings to the Wilwood MC all you have to do is swap out the outlet fittings on the Wilwood MC with outlet fittings from your Z master cylinder. The fittings are the outlet ports that thread into the MC body. The Wilwood and Z outlet fittings are identical except that one is 3/8 - 24 and the other is 10mm x 1.0.

 

The Wilwood rear outlet port marked R has a residual pressure valve intended for rear drum brakes. If you have rear disk brakes you don't want that residual valve (looks like a rubber plug with a spring under it). Just lift the cone shaped part out of the rear oulet and remove the rubber plug and spring and replace the cone shaped part. Then screw in the fitting from your Z. The front outlet does not have the residual valve. I confirmed removal of the residual valve with a Wilwood engineer.

 

I used a 75 280Z booster because I knew that the clevis pin matched the 72 240Z clevis pin. So no mods there. The bolt patterns are different so you need to make a templet of the 280Z bolt pattern and drill new holes in the fire wall. The booster was a tight fit btween the throttle bracket and the 7/8 Tilton clutch MC I am using. I had to dimple the outer edge of the booster about a 1/4 inch where it touches theTilton 7/8 clutch MC. The booster would fit easily if a stock 240Z clutch MC were in place.

 

BTW the first Wilwood MC I bought leaked internally. It happens.

Edited by Miles

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Nice job! We've received some different info from Wilwood on the rear portion of the MC having to remove the pressure valve. I will try to re-verify...

 

In the fittings for the brakes lines - Great to hear the stock lines can be used by swapping the fittings from the old MC - I didn't have one to use to try that so I just made the lines which worked as well...

 

I have 2,500 miles on this setup now and I'm very happy - I did not remove the rear pressue valve and it seems to work fine... more to follow

Edited by kj280z

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