Are there two belts on the generator pully of a 1991 ford F250?

Many manufacturers place a routing sticker somewhere in the engine compartment - did you look around at all for one?

Check the pully on your a/c unit. Mine on my 2003 ford f250 siezed up and locked the engine up. Prior to that my harmonic balancer pully failed.

Steve

standing in front of truck facing it to the left front of motor you will see one of the pullies has a square slot on the arm this is a spring loaded tensioner put a 1/2 inch drive break over in the slot and push against the spring not much room and be very careful that the breakover does not slip once you push belt will loosen

the only part of the belt that touches the back side is the idler pully all other pullies are on the inside of the belt

was this the bolt in center of the tensioner pulley? if so you will need to remove and replace the tensioner assembly, if not which bolt did you break?

Yes, the front pully is the belt drive and that must come off to get to seal. The radiator has to come out to take the pully off. The pully should come off easily once retaining bolt is removed. It can only go back on one way. Goood luck

THE IDELER PULLY MORE LIKELY BUT IT MAY BE A ALTERNATOR BEARING TO

from front of engine looking back,belt around bottom of crank pully,water pump is just above,left side of belt comes around water pump going counter clock wise,put belt over alternator,then straight across to a/c compressor,(make sure belt goes under any idler pullies,smooth side of belt to smooth side of pully)find your belt tensioner,pry back on tensioner(be carefull)and carefully place belt under roller pully of the tensioner,release and check allignment of belt prior to starting.oh ya make sure belt is in good condition.

Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} 1 To replace a worn belt, locate the idler or generator pulley.
2 Loosen the hold-down fastener for the idler or generator pulley.
3 Pry the idler or generator pulley inward to release the belt tension and remove the belt.
4 Match the old belt up for size with the new replacement belt.
5 Observe the belt routing diagram in the engine compartment.
6 Install the new belt over each of the drive pulleys. Often the manufacturer recommends a sequence for feeding the belt around the pulleys.
7 Pry out the idler or generator pulley to put tension on the belt.
8 Pry out the idler or generator pulley to put tension on the belt.
9 Install the belt squarely in the grooves of each pulley.
10 Before adjusting belt tension, check for proper pulley alignment. This is especially critical with serpentine belts. Measure the belt deflection in its longest span. If a belt tension gauge is available, use it and compare the tension to specifications.
”If a belt is too tight, wear to bearings for the water pump, alternator, and engine crankshaft can result.”
11 Pry the idler or generator pulley to adjust the belt to specifications.
12 Tighten the idler or generator pulley fastener.
13 Start the engine and check the belt for proper operation.

the belt that turns the alternator is called the serpentine belt. this also usually runs your fan and is sometimes also called an "accessory belt"

If you look down at the belt area, you will see a pully toward the front of the car that looks like it's attached to an arm. That is the tensioner pully. The tensioner is spring loaded. If you look at the arm of the tensioner there should be a square hole in it to insert a socket wrench or a breaker bar/pull handle to use as a lever to remove the tension from the belt. If there is no hle, then use a wrench(possibly 15mm) on the bolt head of the pully itself as your lever. As you hold the tensioner out of the way, unloop the old belt. Pay attention to the routing, so you can reinstall the new one correctly. Then, you route the new one in and again use your lever to move the tensioner so you can get the belt over the last pully. I usually put it over the alternator last. Use a light to make sure the belt is fully on all 5 grooves of every single pulley before you start the car.
You can also go to chilton.com and look at your cars manual