Technical belt cracks

After 500 miles the water pump/generator belt on my EAB is separating at the base of each lobe. I added the second idler ( @ generator bracket ) because I felt that without it ,possibly the driver side water pump was slipping. Any suggestions would be most welcome.

 

That's a whole lot of load for a single belt.

 

Not a lot of contact on the left side pump .


How old and what brand of belt ?

 

My experience with cogged belt's like that have proven very similar to yours, they started separating at about 300 miles, I went back to a older style conventual Gates belt and have had no problems since. HRP

 

The belt was sourced from Napa. It is 5 years old

 

I have separate temp gauges and have used a temp gun on the discharge outlets. The readings are within 5 degrees of each other !

 

Thanks Danny, I'll try your suggestion.

 

5 years is about life expectancy these days

 

I think the problem is the cogged belt and it being to long, and excessively tight to prevent slippage. You've added idlers that pinch and fold it back and forth in it's travel and the gap between cogs acting as notching locations for cracks to occur.
Like folding a tin can back and forth till it cracks then breaks. But that is a guess.

 

Yep, V-cog belts don't like to bend over backwards...

 

Bingo. Plus, I am guessing the overall tension is quite high to keep from slipping on the water pumps, causing excessive side loading (pinch) on the belt when going around the gennie. All this leads to the cracking.

 

As others have said, the belt is overloaded and unsuited for bending backward.
However the cracks appear to be only in the unreinforced area of the belt, the corded section that holds it together appears intact.
If it were on a regular engine just driving the generator and water pump it would probably last a long time even with the cracks.

 

This.
I have had this belt on mine for years, still looks fresh.

 

Totally different construction if your talking about the blower belt. From the view of the photo, your Gen/waterpump belt does not have cogs I can see.

 

I agree. 5 years is about the life of a belt with the sorry rubber we get now. I bought a Dayco belt a few years ago that broke 5 minutes after I put it on, and it was only running the alternator and water pump. Put a Gates belt on it and it's still there, years later, and still looks like new.

 

You need more wrap on the drivers side water pump pulley, no matter what belt you use.

 

No, you misunderstood my post. I agreed with @Montana1 comment that cogged belts don't like to bend backward. Mine water pump belt is designed to run on its back and it has without trouble. The OP is running the wrong type of belt. I should have been more clear.

 

Even cog-timing belts on OT cars don't like to bend over backwards, because they also start to come apart in the same place, but usually after about 80,000 miles or so...