Belt routing 1976 360 with A/C

76minnie · July 10, 2015, 01:38 PM

My A/C wasn't hooked up for some reason. I am trying to replace belt and see if I can get it working. Anybody have same set up with A/C? Or a diagram showing belt routing? There is a idler pully I can't figure out? It's a 3 belt system, 2 to alternator/ac? It has power steering
Thanks in advance

Oz · July 10, 2015, 08:37 PM

You can bet it was taken off because it wasn't working any more and a PO figured to bypass it and take the pointless work off the engine. I don't know off hand of anyone who has a working, original A/C unit that's 40 years old.

76minnie · July 10, 2015, 09:55 PM

Well, my plan is to fix it. If it's not working. Kind of hard to diagnos what's wrong with it without a belt attached to it. The clutch does click. But like I said, kinda hard to get any further without a belt. But thanks anyways👍🏻

76minnie · July 11, 2015, 02:27 AM

Well, I pushed on shrader valve and their was still pressure in the lines after all these years. So can't be much of a leak. I put one belt on and put power to the a/c clutch. Put in maybe half a can of R12 replacement in and it started blowing cold air. Then the belt popped off after about five mins. If I can't find out the correct routing of the belts, I guess I'll re-look at things and figure out my own belt routing and try and find some belts to fit.

Rickf1985 · July 11, 2015, 09:04 AM

It could possibly be overcharged and that is why it threw the belt unless the routing was wrong. The 454 Chevy is famous for throwing the AC belt. There is a lot of strain in it. What I suggest is to put a set of AC manifold gauges on the system and see what you have before going to far. Without knowing what went on before you you do not even know what refrigerant is in there. You need to see what the pressures are bot on the high side and the low side. The fact that it blows cold air means the compressor is good but what about the dryer and orifice tube? What refrigerant are you putting in? Do you still have R12 laying around?

76minnie · July 11, 2015, 03:45 PM

I don't believe it's over charged. I have the hand held hose with gauge on it, it didn't even register when I started. The system is designed to use 2 belts, I just can't figure out where they go. Autozone and O'rielly's list using 2 of the same belts for ac/atl. The only pulleys that have at least 2 grooves is ac/atl and crank has 3.

Rickf1985 · July 11, 2015, 07:10 PM

But you are only seeing the low side pressure with that hose, you need to see the high side also. Both readings together tell the whole story. Be careful what you are putting in there, a lot of the aftermarket refrigerants sold to replace R12 are very high in butane and can explode if the right conditions are met, like high head pressures and temps.

76minnie · July 11, 2015, 07:48 PM

I'll borrow some gauges from a buddy and check it out. But only after I can figure out how the belts are suppose to go. Napa had same belts listed as others did. And no diagram showing how they rout. It's frustrating. Thx for the replies Rick, and yes it's a freon replacement that seems to be butane or propane based. I do understand the risks of that. But I don't want this thread to turn to a discussion about that.

Rickf1985 · July 11, 2015, 08:02 PM

Take a piece of clothsline and wrap it around the pulleys and see if it is straight from one to the next. Do this for both grooves. Mark a line across the grooves and when you wrap the rope around one pulley set start the rope at the mark and then mark the rope when it comes back to the mark. Now wrap it around the other pulleys and see if it is the same. If it is then you can take that rope to the parts store and use it to get a measurement for the belts you need. The third groove on the crankshaft is probably the power steering.

76minnie · July 14, 2015, 02:58 AM

Thanks Rick, I guess I'll have to go that route. I'm a lil bummed out on the whole thing. I was suppose to be leaving on a trip to San Diego on the 19th and take rv. Some 16 girl with only a learners permit plowed into the back of MH a couple nights ago, just to much stuff to deal with b4 trip. I'll still take trip, but MH not going :-(

Winnebago · July 14, 2015, 04:56 PM

Dealing with a similar issue but in a 76 440-3. Not to say this is correct, but the existing route on my rig is: three groove crank, 2 groove fan, 2 groove ac: inside groove to the fan and alt, middle groove to fan, ac and ps, outside groove to ac and idler pulley.