Lotsa pedal travel with 4-runner brakes. Any ideas?

[Guest Anonymous]

I purchased the 4-runner kit from a person that posts often on this list. I also purchased a 280zx master cylinder from him. I installed everything, did the necessary bleeding of the brakes and took it for a spin. I have a LOT of pedal travel before the brakes engage. If I apply the brakes 2 times quickly in succession the pedal comes up. I have bled it again thinking I had air in the system and that didn't help. The pedal is firm, it just travels way too much before engaging the brakes. Any ideas? thanks,

Peter

[Scottie-GNZ]

Peter,

 

My setup is 82-83 F calipers, 300ZX F rotors, early 280ZX m/c and 2+2 booster. I had (have) the same problem. Car stops fine but the pedal feels soft on top. What did help improve mine was a proper bleeding of the m/c. The next step is to pull the m/c and experiment with adjusting the rod. It is not high on my priority list because I know the car stops fine especially since upgrading to KVR pads all around. Now it is just a matter of brake feel.

 

BTW, my rear setup is all 82-83 w/Maxima bracket.

 

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Scottie

71 240GN-Z

Scottie's GNZ

[Guest Drewz]

I had the reverse problem, my brakes were dragging when I did the swap. All I did was turn the adjusting rod in and I have a small amount of travel and then its "windsheild kissin' time" !!

Give it a shot?

 

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The only stupid question is one you wanted to ask but never did!!!

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Drewz

[Owen]

So is the M/C swap and booster a good thing to do? Do I get them both from the same year car?

 

DrewZ,

What adjusting rod are you talking about?

 

Owen

 

 

 

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http://www.homestead.com/s30z/index.html

[Guest Drewz]

When you remove the master from the booster there is an adjusting rod there. You crack the 7 or 8 mm jam nut loose and turn it in or out. WARNING!!! This is very rusty in my case and took some care as to not strip it. Pretty simple stuff but I discovered it when I replaced the master with a rebuilt one when it blew the seal when I swapped the calipers to 4x4 toyota's and tried to bleed it out.

 

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The only stupid question is one you wanted to ask but never did!!!

http://ca.photos.yahoo.com/andrewzcars

Drewz

[Scottie-GNZ]

Owen,

 

A booster upgrade is IMO, a good thing but the one you use depends on your cars model and trans. The booster is going to allow more brake pressure for a given pedal pressure. The one I am using is the biggest diameter and requires mods to the hole and bolt pattern to fit it. I can use that one because I use an automatic and got rid of the throttle linkage bracket.

 

From memory, here is the swap scenario.

 

-240 & early 260, 5-spd can use the 280 5-spd booster

-Late 260 and 280 5-spd can use the 280ZX booster

-Automatics with cable linkage can use the 280ZX 2+2 booster.

 

Hopefully someone else can verify that.

 

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Scottie

71 240GN-Z

Scottie's GNZ

[BLKMGK]

Did you "bench bleed" the master? I watched someone nearly pull their hair out after swapping a master on a Bronco who didn't bench bleed. Silly thing had air in it and no amount of wheel bleeding would get it out. We had to pull the hoses from the master up front, loop them into the resevior up top, and cycle the fluid round and round till the air was out. Once done it was perfect - real head scratcher for awhile. If it's just soft up top the adjuster rod might also be a good idea to fiddle with - PITA that it will be. Since I'm swapping all of my brake stuff at the wheels I'm sure I'll have probs too but I've got NO idea what I'lll be using for booster and master just yet (sigh).

[Guest Anonymous]

Man, getting at those booster/master cylinder nuts in the pedal box/firewall, I'd rather have my Jimmy slammed in a screen door than have to do that again. With the right swivels I got to them, but it is not for people with big hands thats for sure (at least in my 72).

 

Lone

[Drax240z]

Lone I hear ya. Trust me its no better on the 280zx's either. For some reason I decided I wanted the booster and M/C from an 82turbo. Upside down on the floor trying to get at those bolts, using a 12mm deep socket, 2 extentions and a U-joint.

 

Ended up with cuts all over my hands, and a face full of falling dust and debris. Oh yeah, then I found out the booster and M/C wouldn't even fit for what I wanted to do, so it was a waste... heh. Live and learn!

 

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"Nothing is fool proof to a sufficiently talented fool."

 

Richard Lewis - 1972 240z, Powered by a Nissan 2.8L Turbo Inline 6.

Drax240's Turbo Site

Beginners Turbo FAQ & Answers

[Modern Motorsports Ltd]

The ZX MC's bleed fine as installed IME, done a couple now. If 2+2's or ZX auto's have a larger booster as Scottie says that would be a neat gem of info..an actual upgrade to my rig from a ZX for a ZX

 

Rich, I could use your dud MC/booster that didn't fit

 

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Of all the things I've lost, I miss my mind the most.

[Drax240z]

Sure Ross, why not. I even cleaned them and refinished the master for ya. Looking for a 280z moustache bar if you want to trade... But lots of other stuff I'm looking for too.

 

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"Nothing is fool proof to a sufficiently talented fool."

 

Richard Lewis - 1972 240z, Powered by a Nissan 2.8L Turbo Inline 6.

Drax240's Turbo Site

Beginners Turbo FAQ & Answers

[TimZ]

Someone posted a very similar problem on the izcc mailing list recently - it turned out that their problem was that the calipers were reversed right to left, making it impossible to bleed it completely. The bleeder valves have to be at the highest point in the caliper.