Hello:
I have edited my question, hoping to look a little less stupid than I did.
To sum up, my belt wouldn't fit because I was looking for and buying the wrong belt. Gary straightened me out and now I think I have found the correct belt.

Thank-you.

 

The belt that drives the water pump should also drive something else - like the alternator. And you don't loosen the water pump to install the belt, you loosen the other part.

 

Hello Gary:
I just looked and can't see any other place for the belt to run. I have owned the truck for about ten years. Could someone have made their own pattern?
Both places on the alternator have a belt, also the power steering unit.

In the photos, the new looking belt with the small holes is a temporary air pump belt I installed. I don't see anywhere else for the air pump belt to go.

I think I recall the belt that broke being very thin and small looking.

Thanks for looking and for opinion.

 

The unit at the top of the next to last picture, and at the very top of the last picture is an A.I.R. pump. That stands for, IIRC, Air Injection Reaction, but it is frequently called the air pump. It is used to inject air into the exhaust gas ahead of the catalytic converter so there is plenty of oxygen to react with the hydrocarbons in the fuel.

So, if that is what you are loosening then that is the correct way to install that belt. As for the length, I would keep trying until I found one that fit.

 

Thank-you Gary.

 

Gary:
What would happen if I just left the air pump unconnected and not functioning? Would it affect performance?

I think, in NC you don't have to get an inspection after a vehicle reaches 35 years old.

Thank-you for opinion.

 

I don't believe your truck has a computer, but it might. If it does then leaving the belt off could make the computer mad and it could put ignition timing into limp-home mode. But, if it doesn't have a computer then leaving the belt off will have no consequences.

The easy way to tell is by looking at the distributor. If there is a vacuum advance unit on it then there is no computer. A vacuum advance unit is usually a shiny aluminum-looking part with a vacuum hose going into the middle of it.

Another way to tell is by looking at the ignition module screwed to the driver's side fender. If the plastic grommet where the wires come out of it is blue then there is no computer.

 

On a six cylinder, the air pump is driven by a short and somewhat small v-belt which connects to the outer groove of the alternator pulley [at least on 1984-1986].


What year is the O.P. truck?

 

1981, David.

 

Thank you, Gary. I should have looked more closely.

I just looked at mine to refresh my memory... looking at the crankshaft 3 groove pulley from the driver's side, the groove nearest the engine has 1 belt which passes around the bottom pulley, around the H2O pump pulley [nearest the engine] and around the alternator pulley [nearest the engine]. A v-belt begins in the middle of the crankshaft pulley, around the middle groove of the water pump pulley to the P/S pump. The 3rd belt begins in the crankshaft pulley in the groove nearest the radiator, passes in the 3rd groove [nearest the radiator] of the H2O pump and then to the A/C compressor which is mounted on the driver's side.

The A.I.R. pump is driven by the previously mentioned narrow and short v-belt which originates in the more narrow groove of the alternator pulley [nearer the radiator].

The alternator belt is tightened by adjusting the alternator.
The A.I.R. pump has its own adjustment.
The P/S belt is tightened by adjusting the P/S pump.
The A/C belt is adjusted by moving the A/C compressor.

When you think it through, the system on my truck has all belts [except the A.I.R. pump] passing over two pulleys before driving the accessory. This will help prevent slippage.

Is it possible the belts are not on correctly and were wrong 10 years ago when you purchased the truck?

 

IIRC there's a belt diagram routing diagram for this engine in the parts book but I forget exactly where...

-could be with the A/C compressor section
-or with the alternators
-I don't think it's there but I guess it could be with the cooling/grille stuff

 

David - I'd had the same thought about the belts being wrong for a long time. So I looked through the 1981 factory shop manual, the master parts catalog, and the 1981 owner's manual. And I could not find anything about the routing of the belts. What I did find is this from the master parts catalog showing the belt sizes for 1981 six cylinder engines. Note the sizes for the air pump, in the green box.

 

Thanks, Gary.

 

Well done, Chris! This was in the A/C section, #180:

 

The 302 I had used the short belt from the alternator to the air pump too.