Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Elliott on September 29, 2023, 12:37:49 pm

Title: Cat 3208 AC compressor belt adjustment
Post by: Elliott on September 29, 2023, 12:37:49 pm
My compressor belt squeals and I believe it's due to a belt that's not tight enough. It looks like it's adjusted out to its max tension. Do I have any options other than removing all the other belts and replacing it with a shorter belt?
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Dub on September 29, 2023, 01:18:28 pm
I think not Elliot, like I mentioned earlier I only did that once on my 3208 so it's been a while but if I recall correctly everything toward the fan from that belt has to come off first. I hope I'm wrong but I fear not.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: John44 on September 29, 2023, 01:30:17 pm
Try adjusting the "looks like" may be decieving.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: oldguy on September 29, 2023, 01:41:46 pm
You could put a shim under the compressor.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Dakota Slim on September 29, 2023, 02:27:54 pm
While you are dealing with those belts, take a look at the tensioners. The bearings on one of mine went bad so I replaced the bearings on both of my tensioners. The bearings were much cheaper than new assemblies but you need a press to remove the old ones and install the new. I had the CAT dealer do that for me at their shop.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: wolfe10 on September 29, 2023, 02:31:01 pm
Often, even a bench vice can be used to change bearings in the tensioner pulleys.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: John44 on September 29, 2023, 02:35:28 pm
Do you have a tensioner pulley,looks like you just move the compressor.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Elliott on September 29, 2023, 02:55:28 pm
Do you have a tensioner pulley,looks like you just move the compressor.
No tensioner unfortunately, you adjust it by sliding it on the slots in the plate that it's mounted to above
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Olde English on September 29, 2023, 03:31:37 pm
I was hoping to help but your belts are laid out totally different to mine, on the 3208 in my coach the compressor and the alternator are on the same double belts and adjusting is with the alternator mount.
My compressor is mounted on the driver's side and the alternator is on the passenger side, double shiv double belts to both.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Elliott on September 29, 2023, 03:35:01 pm
I was hoping to help but your belts are laid out totally different to mine, on the 3208 in my coach the compressor and the alternator are on the same double belts and adjusting is with the alternator mount.
My compressor is mounted on the driver's side and the alternator is on the passenger side, double shiv double belts to both.
It seems like an odd place to put a compressor to be honest. It's very susceptible to damage if you drag the tail end as you exit a steep driveway.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: red tractor on September 29, 2023, 08:01:40 pm
That is how the compressor was mounted on our 84 with the 3208. On the unicoach with the 3208 the compressor was mounted in a different location.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Protech Racing on September 30, 2023, 12:36:37 pm
It seems like an odd place to put a compressor to be honest. It's very susceptible to damage if you drag the tail end as you exit a steep driveway.
Yes.  Mine had scuff marks on it before I removed it. You might try a Dayco belt 1/2 in shorter .
I mounted my gm alternator in the same place.  I have scuffed it also. I still have a mild squeal on occasion    . It needs to be really tight . Imho
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Twig on September 30, 2023, 02:16:21 pm
For my '87, I fashioned a spreader out of a turnbuckle to get the belt tighter.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Elliott on September 30, 2023, 02:18:49 pm
For my '87, I fashioned a spreader out of a turnbuckle to get the belt tighter.
Twig do you have any pics you could share? I'm having a hard time envisioning it.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: craneman on September 30, 2023, 02:30:32 pm
If you want to just tighten it for now put some large area washers between the compressor and the plate.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Twig on September 30, 2023, 04:27:02 pm
Twig do you have any pics you could share? I'm having a hard time envisioning it.
Unfortunately no. I gave it the the guy I sold it to. But it was one of these and at one end I put a bolt so it would fit flat to an engine surface and at the other end I think I cut a groove to place either the pulley or the pulley arm, into. Then turned it to extend it.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: John44 on September 30, 2023, 05:40:28 pm
Look in the Grainger catalog for a electric motor belt tension tray,may be able to mount it someway,and look for some of that
rubber/plastic material they put under side by side vehicles,comes in half inch,could glue it to the bottom.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: red tractor on October 01, 2023, 08:06:47 pm
On the 3208 there are two belts on the passenger side of the engine that are pretty short and there is a pulley that is the adjustment for their tension. They drive the alternator and and the air compressor. If they are not really tight they will squeal especially when you first start because the alternator is charging full blast and the air compressor is building up air. I made a spreader to help get it really tight. I used 2 sockets with a bolt and nut so I could force the pulley to tighten the belts. I replaced the belts on lots of the 3208 rear radiator. Flat rate paid 2 1/2 hours to replace the belts. I think there was 9 belts to change.
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Elliott on July 29, 2024, 11:54:32 am
Finally tackling this while I'm at my parents house. Can anyone tell me the adjustment specs for the AC compressor belt? Or give me some guidance on getting it close? We are going to put a thicker plate in between the mounting surface and the compressor and as I understand it overtightening is worse than being too loose so I want to get this right
Title: Re: Cat 3208 AC compressor belt adjustment
Post by: Protech Racing on July 29, 2024, 06:01:43 pm
Tight , plus a little.
It pulls opposing the items driven above it.  So really tight counters the rest of the stuff.
  I added a large spring in lots of tension to drive my alternator.  It still squeals occasionally .