Nick it needs a pump.
Pullin the bed is the easiest.
Pullin the bed is the easiest.
Can I pull the bed on the white Tahoe?
I think it's going to need one too. Remote start often takes two times now and manually, it sometimes cranks a little longer than it used to before it fires up. It seems louder than normal too.

Check valves do fail. It is part of the pump assembly. I'd bet your pump is failing. Put on pressure gauge and get the reading, key on, engine off. Post it. See how long it will hold pressure after you turn key off. 55-62 lbs is the spec. Even 1 lb or so below spec will make a difference in how the vehicle starts/runs