anyone know about serpentine belt tensioners?

[ulysses]

I'm trying to loosen the belt on my 95 Sonoma so I can replace the alternator. I think I get the idea behind sticking the ratchet into the little square hole and hauling on the thing, but then how do I pull the belt off the alternator?

You're gonna tell me I need to buy a tool made for this one specific purpose, and that I'll use once, aren't you?

[CanuckAmok]

1. Without looking at a Sonoma...

I'm going to speculate that either the alternator can be repositioned slightly, on a sort of pendulum movement. What you want to do is loosten the alt bolts enough to be able to move the alternator closer to the engine, thereby loostening the belt.

"Alternately" there will be some sort of an idler pully somewhere along the belt. If there's a pully that doesn't seem to be attached to anything, that's the idler. Loosten the idler, and bob's your uncle.

[ulysses]

2. ok

Thanks. :)

[CanuckAmok]

3. don't let the fact that I can't seem to spell "loosen" correctly...

...allow you to assume I'm a dingbat.

[ulysses]

6. hey,

I teach too many smart kids who can't spell their own names consistently to assume that. :)

[Mr Rabble]

4. This is correct.

[ulysses]

5. I got the belt off

but in trying to get the alternator itself loose, and because I am a doofus, loosened a bolt at the back of the housing that the alt. seems to slide into. In doing this, I was greeted with a high pressure spray of what looks an awful lot like coolant. Is that what it is, or do I need to check other fluid levels?

[ulysses]

7. never mind.

I just realized that I've been yanking on the stupid water pump. Or something. It ain't the alternator, at any rate. :dunce:

[CanuckAmok]

8. uh oh.

okay, then you may have breached the waterpump seal/bearing by pulling it too far forward.

While you have the alt and the belt off, you might as well change your waterpump assembly (pump, bearing, gasket). This is a cheap fix... a Pep Boys waterpump should be about $20 and includes the gasket(s). Use a good gasket sealer (I use Permatex).

What you don't want to do is put everything back together, and then find out your waterpump leaks or is cracked.

Getting the housing off is a snap, but be sure that you clean both joining surfaces with an old breadknife or putty knife, and scrape off the old gasket goop. If you're not careful about making sure all the old gasket stuff is off, you may overly stress the waterpump housing when you're tightening it up, and crack it. It's probably fragile aluminium.

PS drain the radiator first, unless you want another shower! :think:

[ulysses]

9. my more immediate problem

(aside from being an automotive idiot) is that the alternator is well down into the engine compartment. I have no idea how I'm going to get it out.

Thanks for the note on the water pump. Should I change out the belt too?

[CanuckAmok]

10. serpentine belts are expensive...

Examine it for obvious wear/fraying/cracks. If it looks okay, it probably is.

Just a thought, but if you're having trouble getting the alternator out through the top, try lowering it through the bottom... many trucks are designed for fleet/commercial service access, which is traditionally from underneath, not via the hood.

By the way, if your truck has a protective fan shroud, take it out...you'll gain mucho access that way. Bt put it back when you're done.


One caveat: I haven't even peeked uner a late-model GM truck hood in ages, so take what I say with a big fat grain of salt.