IXLR8

Ed, that is what the "Reserve Capacity" specification in minutes is all about. It is usually printed on the battery label along with the 12V, Ah and CCA.

Reserve capacity is the time in minutes that a new, fully charged battery will deliver 25 amperes at 80 degrees F and maintain a terminal voltage equal to, or greater than, 1.75 volts per cell (10.5V battery voltage). This rating represents the time the battery will continue to operate essential accessories if the alternator or generator of a vehicle fails.

Put another way, reserve capacity is a battery's ability to sustain a minimum vehicle electrical load in the event of a charging system failure. Under the worst conditions (winter driving at night), this minimum could require current for ignition, low beam head lamps, windshield wipers, and defroster while driving at low speeds.

IXLR8

Loosening the lock nut of the A/C compressor belt tension adjuster bolt, I assume.

I finally got around to that simple mod last night.

That all-so-easy-to-get-to lock nut....


Its easy to get to that lock nut now...


Lots of room to spin a box-end wrench now...


Of course loosening the A/C belt tensioner is all very nice, but as the OP mentioned, the A/C belt is too short to get off the pulley without taking the A/C compressor off and tilting it towards the center of the engine. Kind of stupid on Porsche's part to choose a 13 x 1085 belt when they are available in 5 mm increments and when the A/C compressor is all the way to the end of its adjustment range.

Roadside cooling fan and/or alternator belt replacement is supposed to be easy...without the need to cut the A/C belt off.

Slow Guy

That does look like a nice mod, suspect it makes getting to that nut much easier.

I don't know why I left out the info on the allen wrench that's needed to get the 3 allen screws that hold the fan pulley together. I need to add that bit of info.

TheOtherEric

That spacer is a good idea. Oddly, I didn't even know there was an adjuster bolt down there, and I've moved the a/c a few times (i just do it by feel).

For anyone who wants that spacer, www.mcmaster.com sells similar spacers and I'm certain they would have one that would fit this application. Just a few bucks.

IXLR8

That it does....makes a world of difference.

When I couldn't get a standard box end wrench on, I tried to "cheat" by trying to loosen the adjuster itself which is accessible and which would back off the lock nut along with it, but it was too tight. An open end wrench at an angle "just" worked but messed up the nut a bit.


Bill, I now carry the following along (just to summarize):

• 24 mm box end wrench
• 10 mm triple square bit with appropriate wrench
• 0.5 mm shims for alternator pulley (964 106 268 31)
• 0.7 mm shims for alternator pulley (964 106 268 32)
• quality 5 mm L hex wrench
• three M6 x 30 shallow-head socket cap screws for cooling fan pulley (900 119 026 02)
• 0.5 mm shims for cooling fan pulley (964 106 517 01)
• A/C belt - 13 x 1085 (999 192 363 50)
• alternator belt - 9.5 x 760 (999 192 343 50)
• cooling fan belt - 9.5 x 776 (999 192 338 50)

Belts listed are for my 1995 C2.
I carry two shims of each size. I lube them up and stick them in a zip-lock bag. Same for the pulley bolts.

IXLR8

Great idea, but I have to use my lathe for something.

You're looking for an ID of 8 mm or 0.315 inches, an OD of 16 to 19 mm and a length of about 20 mm (my spacer is 22 mm long). Note: the spacer length will be dependent on the position (belt size) of the A/C compressor. Too long a spacer and you might not be able to turn the adjuster in far enough.

McMaster-Carr PN: 92510A804 - 0.315 ID x 3/4" OD x 3/4" long.

McMaster-Carr PN: 92511A104 - 0.315 ID x 3/4" OD x 7/8" long.

Gunter

Please, confirm: 3 x M5 x 30 shallow-head socket cap screws for cooling fan pulley.
On another thread, these were given as M6 x 30.

Pelican:

900-119-026-02-M100 Alternator Pulley Bolt, 6 X 30mm, 3 Per Car, 911 Carrera/4 (1995-98), 911 Turbo (1995-98), Each [More Info] [view in catalog]
Brand: Genuine Porsche $1.50

I think they're M6 and need an 5 mm Allen. ??
Thanks.

Good list, Alex, a must to have.
A 15/16" box-end cut in half compares to the 24 mm.
I found 2 x 0.5 mm shims seem to give the right tension for the OEM belt on the ALT pulley.

IXLR8

You're correct; I've made the correction to the list. Thanks for pointing that out.

I had the 5 mm hex key in the back of my mind when I wrote that.

If the 23.8 mm equivalent fits, why not. I bought a "Powerfist" 24 mm combination (open/box end) flank drive wrench at Princess Auto for $8.99.

Its always a good idea to have some extra shims. When I installed a new alternator belt, the existing shims that were previously installed made for a belt that was far too tight. I now have 3 x 0.7 mm.

Tension was set using a Dayco KriKit I V-belt tension gauge.

http://www.youtube.com/watch?v=z11wfc-0-hY

SkiDan

IXLR8 - Very useful information and a clever mod. Thanks for sharing.

csertich

Thanks for the comprehensive list. I was prepared with belts but short on tools. Lucky I had my friends with me when my belt broke.

Belt sure made a heck of a noise when it let go at 6000+ rpm in third gear.

chuck

ginch

So if you're not too worried about the A/C, can you just cut the belt (vs. loosening the ac compressor to remove the belt) should the fan belt break?

IXLR8

You could to save time roadside, but it might be one hell of a hot drive home, depending on the season.

Loosening the four bolts on top of the A/C compressor and the adjuster to allow it to slide in its mount would be fine, but the belt commonly sold (13 x 1085) already places the compressor at the loosest position in its travel. You now have to remove those four hold-down bolts (and not drop the nuts) to get a belt on.

The Porsche parts catalog lists a 12.5 x 1085 A/C belt. Although it would ride lower in the pulley, I doubt you'd be able to slip it over the pulleys. I'm going to look into a slightly longer belt.

IXLR8

That is exactly when mine went. Mind you, the belt was still original.

Gunter

Don't see why not.

Good point about about tension and extra shims, Alex.

Just a few weeks after I bought the Colibri, the ALT belt let go with a bang on a tour far away from home.
Had a spare but found that Porsche no longer included the 24 mm wrench, or the 10 mm triple-square, or spare shims in the tool kit.

Someone in the group had a 24 mm and I managed with a regular Allen carefully jammed into the shaft to open the big nut. Only 1 shim inside.
After installing the new belt, I found it too tight with just one shim.
Opened it again and installed a shim cut out from a pop can. Much better.

Scenery was nice though and the group was patient:

SkiDan

[SIZE="2"]"You're looking for an ID of 8 mm or 0.315 inches, an OD of 16 to 19 mm and a length of about 20 mm (my spacer is 22 mm long). Note: the spacer length will be dependent on the position (belt size) of the A/C compressor. Too long a spacer and you might not be able to turn the adjuster in far enough.

McMaster-Carr PN: 92510A804 - 0.315 ID x 3/4" OD x 3/4" long.

McMaster-Carr PN: 92511A104 - 0.315 ID x 3/4" OD x 7/8" long.
__________________
All the best,
Alex[/FONT[/SIZE]]

For reasons best known to themselves, McMaster-Carr would not ship a spacer to me in Canada even though I provided them with a shipping address in the USA. However, Daven Screw Products at http://aluminum-spacers.com/was pleased to sell me aluminum spacers at a lower cost, as follows:

AS75-16-48: 3/4 OD x 5/16 ID x 3/4 L - $1.80
AS75-16-56: 3/4 OD x 5/16 ID x 7/8 L - $1.90.

Shipping cost to BC, Canada is $3.25.

No affiliation, just like to recognize a supplier who is willing to provide service