What is the difference between a FZJ80 and a 4Runner Master Cylinder? (1 Viewer)

GRM

Finding new adventures in old jalopies.
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As the title states: what is the difference between a FZJ80 master cylinder and a 90's 4runner 1" master cylinder?

The reason why I ask the question is that I recently swapped my '86 Pickup rear axle (drum brakes & 15/16 wheel cyl) for a disc brake '96 FZJ80 rear axle. The truck currently runs a 90's Cab and Chassis Pickup 1" master and dual diaphragm booster off a u-haul truck. The brakes felt great with the old drums and feel good now. As I tune the brakes, I want to ensure that there isn't something mechanical I am overlooking (such as the wrong residual valve in a master cyl).

What I have noticed is these issues:
  • The pedal feel is great when driving, but when I hit the brakes hard, I can get the pedal to the floor
  • When pumping the brakes, the engine starts to stumble (WD40 in the brake booster check valve fixed 80% of this issue)
  • The brakes were very mushy when the proportioning valve was set for drum brakes. Then as I reduced the pressure to the rear calipers, the pedal became stiffer.

While I tune the brakes, I want to make sure the internals of the drum brake and the disc brake master cylinders are the same. Can anyone confirm this for me? Is there a residual valve in the master cylinder? I did a bit of research and found that the 4runner and the non-abs fzj80 use the same master cylinder in the aftermarket. But that doesn't mean they are the same from Toyota.

Thanks for your help.
 

GRM

Finding new adventures in old jalopies.
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So whats the difference? Do they have different residual valves in them?

From Toyota- visually they are different because they have different reservoirs. But the cylinder kit (04493-60210) are the same for both 4runner and non-abs Land Cruiser.

Also, a Beck/Arnley 072-9077 (Master Cyl w/o Reservoir) is the same for both 4runner and non-abs Land Cruiser.
 
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