Food saver vac 550 not sealing and now motor Sounds labored and cuts off. Light will not come on.

You have to get vac TO the switch before it can come out.

There may be a couple of items to look at here.... but the most common problem is a source of vacumn to the pneumatic operation of the heat/a/c vent doors....if vacumn is not distributed properly to the vents you command it is assumed that there is either no vacumn to the selector swith panel(broken vac. line,kinked vac. line, defective in dash a/c control panel) or under the hood a defective vac./heater control valve that is stuck,frozen, not allowing the vacumn to pass through it to supply the indash pneumatic controls and/or panel.
Most vacumn systems that i have ever came in contact with incorporate a vacumn supply tank(nothing more then a round plastic vac. resevoir) which is used in sequence with the a/c heater controls, its purpose is to keep an even vacumn supply to all command points continously while the vehicle is being driven, without this supply one will experience the a/c coming from various different non selected dash vents upon acceleration, this is a direct relation to the tank either being defective(leaking vacumn) or its supply hose(usually vey tiny rubber/plastic tubes) being pinched or broken not allowing the vacumn to the supply tank.
listen for vacumn leaks(hissing sound), look for the obvious...broken vacumn lines or hoses, also check for a defective one way vacumn valve on some pneumatic controlled door vent systems(these valves are inserted in a vacumn line one side being the ""in" port and the other side of it being the "out" flow port,typically if these dont work the vents will also devert your a/c or heat all different ways through your dash.
to check these valves, simply remove from the vacumn hose, and apply vacumn to one side,if vacumn flows through the valve, apply the same vacumn to the opposite side of the plastic valve, if vacumn flows through on the opposite side the valve is bad, it should only allow flow from one side not the other. These valves are small and are usually white or black plastic and look like the old vacumn dash pots used on the old carbureated engines only smaller with one small hose in and one small hose out.

sounds like a typical pneumatic door problem ...perhaps a vac. leak to the drivers side a/c door (most likely) listen for any vacumn hissing sounds on that side....or a hose duct loose/leaking which i doubt.

mine was a crankshaft sensor problem. was not able to start until engine cooled down....

u need to replace brake master cylinder is leaking from the seal behind the master cylinder assy easy to replace

HOW MANY MILES...?
COULD BE A TIMING BELT RELATED PROBLEM.

do you have vacumn at the t/c switch when engine is running if not trace the line back to the engine also that line tees off to the vac ball

I take it the truck has over 80,000 mils on it. Even though no codes suspect catalitic converter has melted from a honey come to a solid block of catilist restricting flow. should code o2 sensors if you keep running it. 4x4 actuater may have gone out due to excessive heat. vent door actuator may have lost the rod conecting it to the vent door. when enouphe air hits the door it opens all the way whitch just hapens to send all the air to defrost vents. Hope this info points u in the right directions

Mass air flow meter,.fuel filer clogged bad fuel pump, map sensor vacumn line came off ???

vacumn pressure for your cruise control will be 14.2. Connect a test hand held vacumn pump to control modual and then drive the car to see if cruise control works in any way. Plus, when pumping vacumn to madual, check to see if throttle linkage moves.
Bill