Idiot Brake light

I have an 87 G20 (diesel) and the idiot brake light in the dash keeps coming on. If I give it a quick pump it goes off.

I checked the pads and they are fine. I also checked the brake fluid level and it is fine. The pump level was a little low so I topped it off but the light still comes on intermittently. Does this model have brake wear sensors in the pads?

I looked at both calipers and they are not leaking nor are the rear slave cylinders.


Anyone have any idea what might be going on or what to check?

Thanks

Jason

sounds like a master cylinder to me. not hard to replace and not expensive either

After I topped off the pump reservoir and did some light driving for a few days, light stopped coming on.

I'll continue to watch it but that seems to have resolved the issue.


Thanks