64 Belvedere pushbutton problem

[Edderds]

What would cause the reverse button to work fine when cold but when hot it will not engage. The park lever and all the other buttons work fine all the time. I had a pro check and clean the button box and check the cable adjustment. What would heat up either inside or outside the trans and cause the reverse button not to engage???
Thanks,
Edderds

 

[dvw]

Do you mean the button doesn't stay pressed in? If so my bet is the adjustment is off slightly.
Doug

 

[Big Bad Dad]

Overfilling the fluid can cause this. Had it happen to me.

 

[dvw]

Overfilling the fluid can cause this. Had it happen to me.

The normal fluid level us above the cable where it enters the trans. How can level affect the dash button? I say no
Doug

 

[Big Bad Dad]

The normal fluid level us above the cable where it enters the trans. How can level affect the dash button? I say no
Doug

It dont affect the buttons. But the heat builds up excess pressure and will not allow the valve body to shift into the reverse. Same way a console shift will not go into reverse if overfilled.