240z... 4x4 toyota brake upgrade problems!..need help!

[Guest bigjim240z]

ok..ive been dealing with this for a while now...im finally to the point where i gotta get this car together and back to its owner.i did the toyota 4x4 truck caliper upgrade to a freinds 240z. we used the 300zx front rotors, 1/2 aluminum spacers and toyota 4x4 calipers. everything went together very easily, we also installed the 300zx master cylinder. ok my question is, are we supposed to leave out the aluminum spacer thats stock on the 240z between the powerbooster and the master cylinder?...when i leave this in i get no petal pressure, we can bleed the brakes all day with no petal pressure. if i take out the spacer and just bolt the master straight to the booster i can get a nice firm petal, but the front wheels stay locked up. if i unbolt the master and leave some slack between the master and booster the wheels will spin but then i have no pressure again..man this is frustratin!...and help from somone who has done this swap will be appreciated..thanks.

[Guest bigjim240z]

ok i installed a 280zx master not 300zx..sorry!

[rags]

Your problem is with the booster pin lengh. You need to use a pin from a ZX because the setting for the pin is slightly less than 5mm longer for the ZX M/C than the 240 M/C. I don't think the 240 booster pin can adjust that far out.

 

Joe

[denny411]

What vented rotors do I use with the 87-89 4runner calipers if i want to stay with 4 lug wheels?

[rags]

Z31 300ZX N/A

[brokebolt]

Here is link to a post I've posted a while back.

 

http://hybridz.org/phpBB2/viewtopic.php?p=140795&highlight=#140795

 

As for this problem you face you need to readjust the piston rod that is between the MC and the Booster. The MC has a different flange thickness and the tappered cone that the piston drives is also different. Best of luck. Mike

[Guest bigjim240z]

read your past posts about the conversion but didnt seee anything about the piston rod thats betwee the mc and booster. how do you know where to adjust it to?..could i use a zx rod?..how do the rods come out of the booster..mine will pull out a little bit but not all the way...thanks for the help...please keep it coming..im far from done..worked on it for hours today without any luck..thanks jim

[Guest bigjim240z]

read your past posts about the conversion but didnt seee anything about the piston rod thats betwee the mc and booster. how do you know where to adjust it to?..could i use a zx rod?..how do the rods come out of the booster..mine will pull out a little bit but not all the way...thanks for the help...please keep it coming..im far from done..worked on it for hours today without any luck..thanks jim

[CruxGNZ]

Jim,

Same thing I had to deal with. I put the bigger master cylinder in my 240Z also and had to adjust the rod out a bit. At first I went out to far and the brakes dragged some but still worked. It's really trial and error to get it just right. Adjust it, put it back on and feel the brakes, repeat as necassary... To adjust the rod length, look at the tip of it, there is a cone shapped nut on there. Just use two 7mm wrenchs (if memory serves correctly) and move the cone shapped nut and back it off or turn it in untill you have the pedal feel you desire. I would say move the nut out about 3/16" from the original location and put the master cylinder back on, then bleed the brakes. After that, then play with the rod length, so you don't have a squishy pedal to deal with. About the spacer between the master cylinder and the booster, I say leave it in. My car doesn't have one, so I don't even know what it looks like. But the way you describe it leave it in and adjust the rod out.

 

!M!

[brokebolt]

Mesure the distance from the MC flange to the furthest point of the piston rod on the original MC and piston rod, than do the same on the new MC using the piston rod you intend on using. Set the length of rod same as first measurement. It doesn't matter if it is a larger unit or just a stock replacement this, procedure needs to be done on every unit you install. Mike

[TomoHawk]

Is thisMC pin- problem an issue with the 280Z? I might change min in the spring.

[ZR8ED]

Tomohawk:

 

I have done this very swap with my 280.. 300zx vented rotors, 4 Runner calipers, .314 thou spacer, etc etc...

 

I left my stock 1978 280z master cylinder. I have run my car very hard on the track with no ill effects. I've heard of the smaller mc giving a mushy feel, but I believe that is from improper adjustment. I've let professional drivers drive it on the track, and have not had any complaints of brakes...

 

When I have to replace my mc, I will probably upgrade then, but certainly not before...waste of money better spent on go fast stuff!!

[fl327]

I just bolted up the zx mc and let er rip, everything was good. this was on my old 72. this was with the solid 4piston brakes though, I dont know if the vented ones need more adjustment though.