OK, I have started to mount my master cylinder. So far, it has been much harder than I oringinally thought. Not Hard, just requiring more thought really. My orignal idea was to mount the MC flat on the firewall, with the rod perpendicular to the firewall. As luck would have it, thats not really possible. The MC has to be mounted right below the Powerbrake booster. I am 99% sure that is where the factory mechanical linkage passes through the firewall anyway. (see arrow in pictures) So that is where the MC is to be mounted, simply because it is the only place for it. Hopefully the booster will hide it for that stealth look. Some Master Cylinder Science: The MC needs 1 7/16" of travel. The rod needs to push perfectly straight on the MC, or it will lead to premature failure, or snap the rod right off. The pedal swings in an arc, that means that the rod will not be pushed squarely, but in an arc as well. In theory, at one point in that arc, the rod will be pushing dead straight on the MC. I'll call that the point of perfect relation. For best results, and least amount of rod angle, you want the point of perfect relation in the exact middle of the MC travel, which will be the exact middle of pedal travel too. Which is 23/32", or slighty more than 11/16". The mount on the pedal is has a 2 1/4" swing. Since only 1 7/16" is needed, that translates into a 36% reduction in pedal throw, which leads to quicker shifts...
Hole Drilling Drilling the hole for the master is the most important part of the mounting process. Also, the hardest. Since the pushrod has to be perfect, the hole needs to be drilled in the precise location. I made a mock up rod, stone age, but perfect, see picture. its 2 5/16" bolts, bolted together with the heads cut off each bolt. One end has a 90 degree bend, that fits in the pedal. The other end is ground to a point. The length of this mock up rod is very important, since it will determine exactly where the MC will be mounted. There are a few factors that determines it's length. First the pedal needs to be in the exact middle of it's swing. Since the pedal only needs 64% of its throw, you can decide how high the pedal sits at rest. either you can take the 36% from the bottom, or the top. I elected to take the swing from the top, other wise the pedal wouldn't go all the way to the floor when pushed. So I pushed the pedal all the way down, and pulled the pedal up until the rod mount traveled 11/16". That is the point of perfect relation for the pedal. (If you have no idea why I did this, refer to the "Master cylinder Science" a few threads up) I rigged the pedal so it wouldn't move from the PPR. On the firewall, I marked the exact spot where I wanted the MC to be. I measured between that spot, and the center of the rod mount whole on the pedal. I took that spec, and made the mock up rod that exact length. I made the rod too long, on purpose. I ground the excess of with my bench grinder to a point, once the rod was the perfect length I put it in place. I put the rod exactly where I wanted it to be on the firewall. Aftermaking a few precises adjustments, I marked the hole. Since the rod was ground down to a point, I stepped on the pedal really hard, and the point acted like a punch. then I drilled the hole. after I had the pilot hole, I used an 1 3/8" hole saw for the big hole.
The master needs to sit at a downward angle to jive with the rod. This is more of the point of perfet relation jazz. Check out the illustration...
The master needs 1 3/8" spacing at the top, with 1/4" spacing on the bottom. That gives the correct angle. I had the spacer made at a local machine shop and cost around 25 bucks. not a bad deal. The MC will be bolted to the studs, and the flat part will have holes drilled into it, then bolted to the firewall. Simple, but it works. Here is a picture of it:
SOMEONE STICKY THIS!!!!!!!!! I have everything to do the swap, but my car was originally a 4-speed car... Bellhousing goes to powder on Wednesday, and then, Ill start mine. Got any better deminsions on that bracket??? Please keep us posted and happy :3gears: :3gears: :3gears: :3gears: Michael
For now thats all I have. This weekend the master will be mounted to the firewall, and the rod should be linked up. The master cylinder has a fine threaded 5/16" rod, so I bought a union, and some threaded rod. the original linkage only had a 90 degree bend with a cotter pin, so I'll probably try to make that work. Should be easy. Let me know if you guys have any tips or suggestions, or even questions. If you want a picture of a certain something, let me know... thanks Joe :beer
Ok, I only have PSP 4.0, so cut me some slack. it might be somewhat confusing. let me know. I wish I had auto cad. The bracket itself may need to be modified somewhat, so before you reproduce, let me try it out first. I really think it will work fine though. :beer
Hey Joe. I've done this exact swap to my car. I have all the brackets and master/slave combinations. I've done almost exactly all the same things you"ve done, so I think you are on the right track. if you want, PM me and I may be able to help you out a bit. Bob
WOW!!! I wasn't looking for anything that detailed... Hell... Confusing is taking measurements on your head, upsidedown, under the dash, flash light in your teeth, holding your self up with your right hand while measuring and jotting all the info down with your left hand... Thats confusing... uzzled: Sorry it early..... This is a good base line to get started. Thanks, Michael
Here is what it should look like with the lip ground off. I also drilled the big hole for the master. not too shabby.
The MC rod will be linked to the pedal with a heim joint. the MC has a 5/16" fine threaded rod fixed to it. I bought some fine threaded rod and a union, join the two rods, cutting the threaded rod to the right length first. The heim joint has a spherical joint on one end, and a female 5/16" end on the other, so the threaded rod will screw right in. It will be pretty slick. I got the joint from stockcarproducts.com it ran about 4 bucks. Check out the picture...
This is the bracket that the pedal assembly mounts too. It will need to be removed in order to swap the pedals. The four studs go through the firewall and actually hold the booster on. the last two bolt holes are the only other bolts that hold the bracket in place. Those bolts just happen to be the same bolts that hold the steering column. It can be pulled out with the pedal still in place, it takes some time though. Removing the pedals with out takeing the bracket out was a huge pain in the nads. There is one long bolt that holds the auto brake pedal in. For the manual cars, the clutch pedal has a long rod that goes through the brake pedal with a simple clip to hold it in place. it works. Check out the pics.
heres a shot of the pedal hooked to the MC, this is with out the threaded rod peice. I only put this peice together to see how well the peices fit. :3gears:
