Coolant Hose Rests Against New Alternator

[GeoPowers]

Hey everyone,

I recently replaced my 55 amp alternator with a slightly larger 80 amp alternator on my Yanmar 4JH4E engine. The 80 amp is a factory option, and I found a like replacement on E-Bay for a very nice price. The install went smoothly until I put the v-belt on.

I am using a 43 inch belt, and from everything I could find the 43 inch belt was spec'ed out regardless of alternator size. I went with a beefy Gates Greenstripe 9430HD belt for a little extra reliability. Because of the larger size of the new alt, the v-belt was a pain to put on!! I used the shorter of the two mounting holes just to get it on, and I barely got it on as it was. As you can see from the attached pics, there is now zero clearance to the coolant hose. The coolant hose is actually very slightly pinched, although I'm really not worried about restricted flow. The belt is probably a smidge tighter than most, but not too concerned- it still deflects to about 3/8".

My questions: 1. Will it hurt anything for the coolant hose to rest against the alternator housing? On one hand, the alternator will get hot. On the other hand, the hose has coolant running through it. It sure would be a drag if that hose failed! Hmmm...

2. What size belt do you use for your 4JH4? I'm thinking if I could do it all over again I would go with a 47-inch Greenstripe belt, but I've already bought and installed this one. I'll definitely get a bigger belt next time.
Recommendations?

Thanks in advance!

Frank

[delmarrey]

In the hydraulic industry we put a shield on hoses that touch other items that may wear the outer layer.

Take an old thin hose or sheet rubber and tie-wrap it to the coolant hose. Then the next time you need a belt get a longer one. Or buy it now and keep the short one as a spare.

In practice one should put anti-chafting covers on all hoses that loosely set on other objects or tie-wrap them to the other object to prevent wear, especially on diesels.

[MarkJ]

I know nothing about mechanics (I know some of their girlfriends, though...) but why can't you just use the longer V belt?

Mark

[Pelagic]

Hi Frank,
You are right to worry as the combination of heat and the different harmonic vibration from the alternator would prematurely wear down the hose and a pressure leak there is not a good thing.

Delmarrey's recommendation to shield it is correct but depending on how tight it is, you will always be worried that the shield will wear thru and then the hose.

To get a bit of extra tolerance for the shield.... take a look at modifying the coolant hose by trimming a little piece off the end (where I have shown) so that with a little clockwise twist on the other end, it can swing away from the alternator.

I would also shield it.... if for no other reason than as a reminder to periodically check

[sigmasailor]

Just wait for it to fail when you need it most (remember Murphy?) and than think: I should have replaced it when I had the time.

[never monday]

get a longer belt

[Blue Stocking]

New belt--- small expense
Worry about failure-Great
Peace of mind from knowing you did it correctly --Priceless

Happy sailing

[Tellie]

These are areas you don't cut corners. Shielding, tie wraping, and cutting a hose short, are all good "preventative" measures. They should not be fixes for a job that should be done right in the first place. Never Monday, as usual, is short, sweet and to the point. Get a longer belt. Toss the one you installed into your emergency spares box.

[gettinthere]

longer belt and store the short belt as a backup. you should carry a spare anyway.

I save pieces of clean used hose (except head hose!) for chafe protection. Especially after finding a bilge pump hose with a wear hole in it!

[GeoPowers]

OK, thanks everyone for all the replies! When it comes down to it, I was being lazy/cheap by not getting a longer belt, but wasn't sure if it would actually hurt to have the hose in contact with the alternator when it gets hot. It is pretty snug up against it, and I was thinking that the vibration would be in sync for the hose and alt. You are right, it is prudent just to swap it out and get a couple longer ones for spares. If nothing else the extra effort is worth the piece of mind!
I guess I'll toss one or two of the smaller belts I have in with the old alternator as a backup. Anyone up my way want a nice Greenstripe 9430HD v-belt that hasn't been mounted? I bought a couple, and don't need that many spares for the wrong size belt.

Thanks again,

Frank

[motion30]

Go back to where you bought those short belts, I bet they will exchange them for the ones you need if unused

[ViribusUnitis]

Originally Posted by GeoPowers

OK, thanks everyone for all the replies! When it comes down to it, I was being lazy/cheap by not getting a longer belt, but wasn't sure if it would actually hurt to have the hose in contact with the alternator when it gets hot. It is pretty snug up against it, and I was thinking that the vibration would be in sync for the hose and alt. You are right, it is prudent just to swap it out and get a couple longer ones for spares. If nothing else the extra effort is worth the piece of mind!
I guess I'll toss one or two of the smaller belts I have in with the old alternator as a backup. Anyone up my way want a nice Greenstripe 9430HD v-belt that hasn't been mounted? I bought a couple, and don't need that many spares for the wrong size belt.

Thanks again,

Frank

You kept your receipt right? Just return the uninstalled v-belt to where you got it form, and exchange it for the right size.

[GeoPowers]

Didn't buy them local. No biggie, not a lot of money...