C4 Modulator Piston

[ol gray mare]

Is there a difference in years for the modulator piston?

 

[Rustytruck]

the 69 and earlier C4 used a different valve body design don't know if the actual piston is swap able.1970 change then the change to the C-5 in 1982 and I don't know if the valve body in those are swap able with the c4.

 

[ol gray mare]

Thanks for the reply Rusty truck. I'm referring to the piston that is activated by the vacuum modulator on the rear of the trans. I seem to have lost the original one. I found a couple on ebay but they're listed for the earlier years. This is my first c4 rebuild.

 

[Viperwolf1]

Thanks for the reply Rusty truck. I'm referring to the piston that is activated by the vacuum modulator on the rear of the trans. I seem to have lost the original one. I found a couple on ebay but they're listed for the earlier years. This is my first c4 rebuild.

The early modulator valve (used with screw in modulator) has a bigger diameter. The smaller one is '72 and newer.

 

[jckkys]

Are you talking about a piston or the pin under the vacuum modulator. These are 1/8" diameter
and about 1.6" long with rounded ends. I have a couple and could send you one.

 

[ol gray mare]

looking for the piston itself, I have the pin. thanks