82-83 Master Cylinder in S30

[m1ghtymaxXx]

I picked up my first S30 yesterday, a very nice condition all original 77, however it sat for a while and has a few issues, primarily the brakes. The previous owner warned of a brake leak, but wasn't sure where, until he moved it and there was a puddle of fluid by the front passenger wheel. When I got it home, the brakes went straight to the floor, as expected the reservoir was dry...sort of, there was a fair amount of dark rusty coloured sludge. A search here seems to indicated that is good sign the seals in the m/c have been eaten, so that brings me to my main question;

 

I've been reading up the Silvermine/Toyota brake upgrade. It recommends using the the 79-81 15/16" master cylinder, or modifying the 1" Wilwood. I never heard any mention of the using the 82-83, one of which I have in good condition as I only bought the 77 because I pulled the plug midway through an extensive restoration/turbo swap of my 83 due to rot.

 

Anyways, is the 82-83 not used because it's too small? or does it just not come close to fitting? Even if it's not big enough to pressurize the Toyota brakes, it would be nice to have a known good cylinder to build some pressure in the lines to flush out any more sludge and further diagnose issues with the stock brakes.

 

With that said, should I be using anything other than brake fluid to flush the brake lines? Is there something a little more aggressive for clearing them out? Currently I was thinking I'd just blast the lines with compressed air and run a jug of fluid through them.

[BluDestiny]

I believe the bolt pattern to the Brake booster is different. That's why they use the 79-81. I've never had an 82-83 so I can't say for sure, but I know the bolt pattern of the MC from a 79-81 does work ( with some slight modification).

[z240]

Yes, its a bolt pattern issue. The wilwood 1" a good alternative as the 15/16 Nissan ones have become very hard to find. For me its more of a "new" vs "rebuilt" issu.

 

There is a sticky on this forum with the details of what is needed to use the Wilwood master. Silvermine claims to have a source for 15/16's one, either would be fine.

[m1ghtymaxXx]

I've read up on the early ZX and Willwood m/c's, it's just that I have a good 83 cylinder. Even if it wasn't an upgrade it would knock one thing off the to-do list. If it's a pattern issue, could it be resolved by slotting the holes like the Wilwood, or is it a horizontal vs. vertical bolt pattern issue? I should be able to get the 83 next week to actually compare.

 

Of course there's always the issue of whether or not the one in the car is bad or not. I'm only assuming it is based off a few posts on this forum saying the sludge in the reservoir is what's left of the seals. I suppose it couldn't hurt to pull it off and take it apart and find out for certain. If it needs to be replaced I'll go for one of the upgrade options.

[ritrebor]

I believe it is a horizontal vs. vertical bolt pattern issue

 

ritrebor

[RIP260Z]

I have the late 280zx system on my servo. The holes need to be elongated to fit the bolt pattern on the servo (not by much), as said earlier fits onto the servo the other way. This master works without the spacer that is on the early 280zx and S30 (that goes between the servo and the master cylinder). This means the two bolts that are not used on the servo can foul the master reservoir. These need cut down a bit. Also the center rod out of the servo (that pushes the piston in the master cylinder) needs also to be cut down. Otherwise it will constantly pushing the brakes on.

 

Hope that helps

[m1ghtymaxXx]

Well the 82-83 cylinder certainly uses the horizontal bolt pattern as opposed to the vertical in S30s. I think an adapter could be made fairly easily that rather than being a "+" shape like factory, would be be "I" shape with holes to fit the booster and studs "inside" the holes to mount the master (hopefully you can visualize that). Of course someone would need to confirm it also uses the 15/16" piston or bigger. Anyways I've already got the Wilwood unit on order, but since I have the 83 cylinder, I think I'll take it apart and see for myself when I have time. If someone has the necessary machining equipment, or hookups, I suppose a run of adapters could be cut to open up the possibilities for master cylinder upgrades. Especially with everyone hunting for 83 turbo donor cars.

 

I have the late 280zx system on my servo. The holes need to be elongated to fit the bolt pattern on the servo (not by much), as said earlier fits onto the servo the other way. This master works without the spacer that is on the early 280zx and S30 (that goes between the servo and the master cylinder). This means the two bolts that are not used on the servo can foul the master reservoir. These need cut down a bit. Also the center rod out of the servo (that pushes the piston in the master cylinder) needs also to be cut down. Otherwise it will constantly pushing the brakes on.

 

Hope that helps

 

Not sure I fully understand, but you've mounted the the master cylinder to the same studs that mount the booster (servo = brake booster?) to the firewall, and cut down the booster pushrod to compensate for the missing "+" shaped adapter?

[RIP260Z]

Yes Servo is brake booster. The holes on the master cylinder need elongating to fit onto the servo studs and the servo pushrod needs trimming. Never tried fitting with adaptor plate, as following old "how to do". Not same studs that fit to firewall.