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A One Inch Diameter Brake Master Cylinder for the S30 Z Cars

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My push rod is not adjustable for some odd reason and it's about 4mm too short. I'm thinking about taking the spacer between the master cylinder and the booster and have it milled to make up the difference. I would replace the booster but it's brand new and I had it powder coated already. Any other ideas would be greatly appreciated.

 

It is going to turn into a kluge. Just go back to a 280Z booster and sell the 280ZX booster.

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It may be more work, but try installing it and just giving it a try. My pushrod needs to be adjusted, but I don't have time, so I just have a low pedal (but I still have enough). Nice thing is that it puts the pedal at a great height for toe-heeling. One thing I would suggest is to modify your lines to allow you to run flexible lines at the master cylinder. That will let you remove the master to adjust the rod later without having to bleed brakes after every adjustment. Maybe I'll get mine adjusted this winter.

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You can move the MC while it is attached to the hardlines. There is enough flex in the hard lines to pull the MC off of the booster and move it toward the fender so you can acess the push rod for adjustment and/or check if the reaction disk is in place.

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It is going to turn into a kluge. Just go back to a 280Z booster and sell the 280ZX booster.

 

 

You maybe right but I think I'm going to need the larger booster since I'm running the larger master cylinder and Wilwoods front and rear. It should not be that bad, I have determined that I will have to shave 2.8 mm from the spacer to give me a 3 mm clerance. That should not be a big deal, a local machine shop should be able to handle that with no problems.

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It may be more work, but try installing it and just giving it a try. My pushrod needs to be adjusted, but I don't have time, so I just have a low pedal (but I still have enough). Nice thing is that it puts the pedal at a great height for toe-heeling. One thing I would suggest is to modify your lines to allow you to run flexible lines at the master cylinder. That will let you remove the master to adjust the rod later without having to bleed brakes after every adjustment. Maybe I'll get mine adjusted this winter.

 

 

I just don't want to take a chance to get on the throtle and not be able to stop. This car will have over 800 hp by the time I'm done with it and brakes will be needed to slow it down if I ever get traction...:)

I am using the flexible braided lines like you mentioned from the master cylinder to the distribution block on the firewall. I will post some pictures on my thread soon of the progress.

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Well I'm getting ready to do this and for the life of me I can't really figure out doing it the measurement way so I found a push rod depth gauge here: http://www.classicperform.com/Store2/Tools.htm Costs about $30 with shipping. I figure I'll grab this since I don't have any very accurate measuring devices either and they say this is the best tool for adjustment.

Edited by DuoWing

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I am sure it is a fine and dandy tool.  I used a business card with a small Phillips

screwdriver poked through it and a carpenters tape measure.  I rested the

screwdriver in the old MC, slide the card up to the end of the MC, grasped the

shaft(no pun intended) so the card was not deformed and could not move and

recorded the length from the card to the tip of the screwdriver, repeat on the

new MC and being a cheap bastard, re-use the business card to be a straight

edge to measure the pushrod protrusion from the booster.

 

My 76 needed a 1/8" adjustment (3mm), which I am sure I saw earlier in this

thread, so I was comfortable with accuracy tools available to me.

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For anyone wondering my Tokico replacement Brake Master that was in my car was not compatible with the Wilwood so I had to go the route of forming new brake lines. Anyway my measurements for anyone interested fell inline with what Dan_Austin said. I found from the very top of the cylinder bore to the bottom using the push rod that came with the new master for measurement at 28mm. The measurement A I found to be about 15mm. My pushrod stuck out 10mm. So I ended up needing to adjust it out about 3mm. Also for anyone needing help with adjustment I had a person sit in the driver's seat and hold the brake pedal down so the pushrod stuck out nice and far and I could put some vice grips on the lock nut and use a 7mm box wrench to adjust it. I'll probably double check once I get the depth tool, but I feel like this should be good. Now to bleed everything and hope for no leaks...

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Figured I'd chime in, my 77 mastercylinder wouldn't adjust, but it just seemed the rounded end was seized onto the thread shaft. I struggled for a while with vice grips on the threads but never got it to budge. My measurements showed it was just barely within spec, and I haven't had any issues with it on street.

 

I should poing out I'm also using the 1" mc with all stock brakes, and I've found the feel to be just fine, though I the car came with a rotten MC, so I have no idea what the brakes were supposed to feel like. The heavy pedal just matches the heaving steering to me.

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JUST finished bleeding brakes from a leaking wheel cylinder, was lowering the hood from doing the job and what did I see?  Some paint peeling on the booster right below my master cylinder.  Looks like my 3rd rebuilt master cylinder is leaking!  Argh!  I just can't get a break.  I was just thinking about adjusting the push rod when I got home from the weekend's racing.  Hope the darn thing doesn't fail suddenly (looks like it has been leaking for a while) cause I'm going racing anyway, but I'm gonna order the Wilwood 1" kit when I get home.  Did I mention that I suck at brake work?  Anyway, how is the Wilwood master holding up for all of you?  I don't need a bigger MC-I just need one that will last for a few years instead of needing replacement almost annually.  I friggin' hate cleaning all that goo out of the booster.....

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I don't know how efficient it would be, but I had a thought for lines from the new master adapting to the rest of the system. I was thinking you could simply buy say the 14" long Stainless Braided lines that have two -3AN Female fittings and then just use a -3AN male to 10mm male on one end and a -3AN male to a 3/8x24 male on the other. This way you wouldn't have to deal with bending or flaring lines and you'd have flexible lines that easily allow you to move the master cylinder around for adjustment or having to pull the booster.

 

Alright I was searching Ebay and it turns out I just wasn't hitting the right keys, but I found these: http://www.ebay.com/itm/Brake-Line-Thread-Adapter-Male-3-8-x-24NF-Female-M10-x-1-Inverted-Seat-/390439357312?pt=Vintage_Car_Truck_Parts_Accessories&hash=item5ae7ffcb80

 

So maybe we finally have an option for making the Wilwood swap even easier.

Edited by DuoWing

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I got the Wilwood master and a new booster.  However, the pushrod is too long and I can't adjust it.  I have read that you can use shims to fix it, but it is right at 4mm too long and I don't think I want to shim it that much.  Before I go hacking at my new booster to shorten the pushrod, anyone have any recommendations?  Oh and here is a picture in case I am being stupid and it is adjustable but I just fail to see how.   

 

boosterpushrod

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Um since i don't have a booster anymore not sure how helpful i can be. But would shortening the shaft that gose's to your pedal possibly pull your push rod back in? Also realy if its only a 4 mm spacer in inch its around 5/32 thick. So if you would take a nice piece of aluminium and shine it up it could look of, id say better then going and hacking up the rod 

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  1. Do you have the spacer block in place between the booster and MC? If not the push rod will be too long.

Under the dash verify that the adjustment between the booster and the pedal arm is not adjusted such that it is pushing the MC  push rod forward. You need some free play in the brake pedal per the FSM etc.

Assuming that you have a 240Z or 280Z booster, the push rod should be close to 14mm to 15mm +/- a few mm (as measured from the spacer block) for the Wilwood 1 inch MC.

Test fit the MC while adjusting the push rod.  If the MC pushes back when sliding it home on the booster it is too long. If it is too long the brakes will lock up after 2 or 3 stops. When you test drive the car take a wrench with you to release pressure in the MC by opening the MC bleed screws. Note that the push rod can be adjusted with the hard lines to the MC connected.

Do not drop the reaction disk inside the booster. Suggest that you set the booster in a vise so the push rod is pointing up, pull the push rod out, take out the reaction disk (rubber puck) and glue it to the base of the push rod with JB weld. Otherwise there is a good chance that you will loose the reaction disk while fooling around with the push rod adjustment. Search on reaction disk for more info.

Edited by Miles

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I found similar adapters from Brakequip.  BQ50 were what I got.  They have a lot of other adapters as well too.

 

I don't know how efficient it would be, but I had a thought for lines from the new master adapting to the rest of the system. I was thinking you could simply buy say the 14" long Stainless Braided lines that have two -3AN Female fittings and then just use a -3AN male to 10mm male on one end and a -3AN male to a 3/8x24 male on the other. This way you wouldn't have to deal with bending or flaring lines and you'd have flexible lines that easily allow you to move the master cylinder around for adjustment or having to pull the booster.

 

Alright I was searching Ebay and it turns out I just wasn't hitting the right keys, but I found these: http://www.ebay.com/itm/Brake-Line-Thread-Adapter-Male-3-8-x-24NF-Female-M10-x-1-Inverted-Seat-/390439357312?pt=Vintage_Car_Truck_Parts_Accessories&hash=item5ae7ffcb80

 

So maybe we finally have an option for making the Wilwood swap even easier.

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Well at least a couple of adapters have emerged. This should help people especially if you've never made brake lines before. Also another thought I had is that since 3/8-24 is smaller than 10x1 you may even be able to remove the aluminum line adapters from the MC and actually just tap them out to 10x1. Then everything should fit nearly perfect.

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