r16678

I have 1979 L48 with manual transmission, my belt configuration includes only three belts. 1. power steering, 2. alternator, 3 water pump. I can find the first two at NAPA, but I can not find the water pump belt. Does anyone know the size or if a local parts supplier carries it? I know it is available at corvette central

https://www.corvettecentral.com/c3-6...9%26count%3d27

THank you in advance

derekderek

The water pump is driven by both water pump and alt belts. If you don't have A/C, you only have 2.

r16678

Thanks I think there is three, I looked at my 1979 manual and see that my configuration is in the upper left corner.

drwet

That's a terrible diagram. I agree it looks like there are three belts but there are only two. There would be no way to adjust the tension on a belt that only ran around the crank and the water pump.

HeadsU.P.

Some had 3, 4 or 5 belts.

Its a tight fit for a extra belt, but do-able. Belt goes on first, then slowly tighten WP pulley bolts one at a time.

Peterbuilt

Most auto parts stores will find the correct one for you.

http://www.daycoproducts.com/parts?c...cription=11483

Can you find the numbers of the old ones or if they are off the car they can match the length.

lvmyvt76

I called O'reillys, they can not help on this one. I did give the gm part number to the OP.

Bikespace

Shouldn't there be a "Fan only, w/o A.C." belt on that Dayco site? Maybe I missed it.

I did find this old thread with a Gates part number:
https://www.corvetteforum.com/forums...pump-only.html

Neither of my cars has working AC right now, so my alternator belt is turning the water pump (fan), too. As long as that keeps working, I'll keep doing that.

AboveTheLogic

I 2nd this.

My '79 has two belts. One runs the water pump and alternator, the other runs the power steering. It would have three if I had a functioning A/C compressor installed.

The groove for the A/C belt has no belt at all, not a water pump-only belt that the diagram suggests.

donaldb1

The manual you a have is an aftermarket manual. Aftermarket manuals are good, but often use generic photographs and contain incorrect references.

derekderek

At first glance it looks like a double alternator belt. But somebody incorrectly drew the second belt on water pump crank only. To adjust this belt tension you would have to slot 3 water pump holes and move water pump up and down. Would probably cause water leaks and fan hitting shroud... you could get a double at pulley and run 2 at belts...I think.

Torqued Off

I have the belt between the crank pulley and water pump, but it is somewhat loose and I am not sure it is doing anything. The diagrams shown above clearly show this belt should be there, so I bought what I could find.....I think from one of the Corvette vendors, but as I said, it runs pretty loose. Also, FYI my 77 had this belt before I restored it, so I do believe it is supposed to be there. Also if you look at every one of those diagrams for each configuration, there at TWO belts drive the water pump.

r16678

This is the part # GM#3935420

r16678

Thank you, I also saw the image in both the build manual in my image which I attached earlier as well as the 1979 shop manual I got years ago. Also corvettecentral sells the part see link below. That is why I got so concerned about not putting it on. I appreciate everyone jumping in and providing feedback. There is no way I could have gotten as far as I have with my car without this forum.

https://www.corvettecentral.com/c3-6...9%26count%3d27

AboveTheLogic

I can see that little belt maybe being important if you have an air pump, since according to the diagram the air pump is driven solely by the water pump, and the water pump only has about 1/4 of the pulley's worth of engagement with the crankshaft without the little belt in the middle.

I don't run an air pump and I haven't had any belt slippage issues with my water pump as best as I can tell.

So I guess it wouldn't hurt to have a center belt on there, if you want to deal with trying to get it on there.

HeadsU.P.

IWASME is correct. A WP & Crank belt ONLY is do-able but a-son-of-a-gun to get on there. ( I removed my A/C) so I made three attempts with the help of NAPA parts man. Too loose, too tight and the third was I Give Up Size. Consider that extra belt a helper or backup belt to run the WP.
Too loose and its not doing much.
Too tight and WP bearing damage.

Maybe I will try fitment again in 20 yrs. Frustrating.

Peterbuilt

http://www.daycoproducts.com/parts?v...r=3935420&pid=

Bikespace

I would think that if you have WP slippage issues, or are concerned about side-loading on the WP bearings, a better solution might be to install a non-functional AC compressor as an Idler pulley. It would certainly be easier than replacing the crank to WP belt.

If you don't have WP slippage issues, I don't know why you would bother with the belt at all.

HeadsU.P.

I don't want to haul around a dead A/C. I just wanted a back-up belt on the WP in the event the first belt broke. Then you overheat and lose your ALT both. But I gave up on the idea of double belts.

Big2Bird

Did you have any issues? If not, it does zero.