Rock hard brake pedal before engine start

I notice in the morning when I go to start the engine that the brake pedal is hard as a rock. As soon as you start the engine the pedal feels normal again. Is the brake booster trying to tell me it needs some work done to it?

 

normal. the brake booster only functions when the engine is running.

 

Right, but the pedal has never been hard like that before.

 

The booster should hold vacuum while sitting with the engine off. There is a check valve where the vacuum hose goes into the booster. I would check that first

 

And the hose for cracks.

 

Holding vacuum = "normal" feeling brake pedal or rock hard brake pedal after sitting overnight?

 

Yes. You should normally be able to depress and release the brake pedal 2-3 times with the engine off before the vacuum is bled from the booster, then the pedal will be hard to depress

 

The molded vacuum tube visually looks ok. Looks like the brake booster is no longer available. Wonder if it is worth it to swap out the check valve, which is still available.

 

Everybody and his grandma makes or service these brake boosters....

https://www.bing.com/shop?q=53-2581&FORM=SHOPPA&originIGUID=79D173E805044951B11CEAE0F881165A

 

I only use OEM parts. The booster is no longer available. Not sure if the old one is rebuildable. But, could the culprit be the check valve?