Rear A/C Compressor and Vee Belt

loredo_sprinter

New member
If anyone knows how to remove and replace the a/c Compressor belt I'd really appreciate any and all info on the matter. I see in the repair manual that the Serpentine Belt has a tensioneer , does the a/c compressor belt have a similar tensioneer? Thanks a bunch for all responses

Jules :idunno:
 

sikwan

06 Tin Can
At least on my van, you'll need a Torx E14 socket (reverse torx). You'll need to loosen it and then the idler arm releases towards the direction of the red arrow.

belt.jpg

The blue arrow is the spin direction of the belt. I just did the install recently in this thread and had a hard time putting the belt on. So I snugged it up enough and had more of the belt wound around the pulley on the backside of the compressor, blipped the starter to turn the engine, and got the belt to sit on the two pulleys.

I placed an 8 inch crescent wrench for leverage at the end of the idler arm (near the red arrow) and pulled it towards the compressor pulley. I then tightened the torx bolt.

EDIT: I almost forgot. I removed the idler arm before blipping the starter. There's barely enough room in there without the idler pulley touching the v-belt or the serpentine, so I didn't want to risk causing any damage with a loose idler arm.
 

loredo_sprinter

New member
Sikwan,

Wondering where you bought the a/c compressor belt, was it dealer bought @ $57. bucks? If you know a better source I'd like to know thanks again. The picture you took is from the bottom looking up, is that how you did the work on your back looking up ?

Jules
 

sikwan

06 Tin Can
Jules,

The belt came with the kit. If you got the old one, just bring it to any auto store to get a new v-belt. They come in various lengths.

Also, belts are suppose to snap or wear down and do not stretch like chains so the length from the old belt should be pretty close. In fact, you can probably cut it off if you want and measure the length.

That's correct. I laid on my back to do the work. The bottom of the picture is the front of the vehicle.

Seek
 

pgr

Active member
I just went to use my AC for the first time since last summer and nothing! I checked the bottom compressor (2004 w rear air) and discovered no belt! Should the front air still work (it doesn't)? Is the Dayco part # 17380 above the correct number for the lower AC compressor for this year?

Thanks,

pgr
 

sikwan

06 Tin Can
I just went to use my AC for the first time since last summer and nothing! I checked the bottom compressor (2004 w rear air) and discovered no belt! Should the front air still work (it doesn't)? Is the Dayco part # 17380 above the correct number for the lower AC compressor for this year?
The front AC should work independently to the rear. The Dayco p/n is correct. You really don't have to use the brand Dayco as you can use the p/n to cross reference to any other brand.
 

cahaak

New member
I just replaced the belt on my rear A/C and I wanted to share the info on it. It was, in fact, very easy as I will detail below.

I am running a 2006 140" passenger with rear air that I bought used. I know that the van spent a good portion of its life in Texas and other parts south. Looking through the service records I got with the van, I saw that the belt was replaced at least twice before and in fact the idler pulley (tensioner) was also replaced at least once.

So, initially got the van and ran the rear A/C and it was squealing, but that went away. Then my wife says, the rear A/C is not working, please get it fixed (had already had to charge / recharge the front system). I went to look under the van at the belt and - belt is gone missing. So I looked here at this thread and it indicated the Dayco 17380. I did some calling around and nobody had it but they could get it and it was going to be something like $16. Then I went online. Found the 17380 belt at Rock Auto for $5.40 on closeout - great. So I put one in my cart and then I thought, well, I will just look through the parts recommendation on Rock Auto for this part to make sure it matches. Recommended A/C accessory belt they list is a Goodyear 17391. Hmmmmmm... Well, they have two of those on special too for about $5.40, so lets get them also. Two days later all three belts show up. Total with shipping was $23.xx.

Out to the van. Hey, that bolt head on the tensioner is not a torx (E-star). OK, it is just a regular 13mm head, no problem. Loosened the tensioner up, slip on the 17391 belt, apply tension with the adjustable cresent wrench as noted and tighten it back up. All done. My 7 year old helper with limited English skills says "All done?" and I say yep. He is like - wow, that was easy. We take the van out for a test drive and everything works and no noise whatsoever. Now I have a couple of spare belts for the inevitable replacement job.

So, the takeaway here is that you need a 17 series belt, but a 380 or a 391 length will do fine. At least for the 391 length, getting the belt on is very easy and it tensions up just fine.

Chris
 

cahaak

New member
Just replying to my previous thread. In fact, the 17391 goodyear belt is too long. When I first put it on, it worked fine. Apparently they stretch some though, because after about one week of running, the belt was too long and I could not tension it up. I installed the Dayco 17380 belt on the pulleys then, just like describe above by blipping the starter. Got it good and tight and tightened up the tensioner. But, this belt stretches too, I had to retension the belt after about one week again.

So, if you do install a new belt for the rear AC compressor, you really need to retension it again after you have run it a few times and you may need to do that several more times, I'm not sure, but mine has been holding well now for a while. It is easy to check and retension luckily.

Here are a few cross reference belt numbers for the 17380 Dayco.

Gates 9380
Napa 25-9380
All of these manufacturers also make that belt in the 385 length too, maybe that length would go on better but still be short enough to tension correctly
Bando also makes a 4380 and 4385 belt, only issue here is that these are 1/2" wide instead of 17/32" wide like the 17 series, probably would work though if you look at the pulley profile.

Anyway, just some more info for those that have rear AC units.

Chris
 

gtholden

2005 T1N, 140WB, Low Roof Passenger, ~163K Miles
Hi, I just found this post and was under the van doing some visual inspections for prep of a long road trip out west. I've got a 2005 with rear air and when I start up the rear air if it has been sitting in the sun, it makes a horrible squeal and shakes the van sometimes as the clutch seems to engage. once it is warmed up it runs fine.

So I've got a spare belt, but my question is, when I looked at my belt the smooth side was on the outside of the belt and the v-ribs were facing in so they are on the pulleys? In Sikwans picture the v-ribs are facing out, so I'm assuming my belt was put on incorrectly and maybe causing the squeal/shaking. Also, this ribbed belt is for rear air correct?

The belt I have is showing some signs of wear on the edges and cracks in the 'troughs' of the ribs (they are parallel to the v-ribs and perpendicular to the belt itself). I'm considering putting on the new one, but just want to make sure I orient it correctly. Thanks in advance for your help!

vic edit:
It appears that this post crosses over from the rear A/C Vee belt to discussing the multi Vee serpentine belt. Slight cracks across a multi Vee belt are not generally a problem. Cracks in the rear A/C Vee belt would be indicative of excessive wear.
 
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sikwan

06 Tin Can
The V-side of the belt goes towards the pulley. My belt just so happens to have ribs on the outside.

Another way to look at it is the label side is the outside.
 

gtholden

2005 T1N, 140WB, Low Roof Passenger, ~163K Miles
okay thanks Sikwan! would you be concerned with cracks in the belt that are perpendicular to the belt (meaning parallel to the ribs)? From what I've read, it doesn't seem to be a problem...but can't find the installation of this belt in the service manual, just your thread.
 

cahaak

New member
Having done this one several times now, the 17385 belt is the way to go. You can get it on easily and it tensions up nicely. It also just so happens that my local Fleet Farm keeps these in stock for $6.99. I carry a spare with me. I still get the modest noise when I first fire up the rear AC after not having used it for a while, but runs fine after the initial fuss. Based on my experience after the winter, I think that the belt replacement might end up being an annual thing for my van, but I can handle the 5 minutes and $6.99. Just driving to Chicago last weekend and 92 out and we needed the rear AC to keep the kids cool and happy.

Chris
 

HoHum

New member
Sorry to resurrect such an old thread.

I have a 2005 2500 with under 70,000 miles. I, too, experience the ridiculous squeal when turning on the rear AC initially. The question I have is related to the original belt that was on there. I'll probably go find a new one and replace it shortly; however, in the mean time, I still want to tension it again. The two questions I have are:

1. How much tension can the original belt take? If I really pull hard on it, I can get the idler arm to almost touch the compressor pulley. I'm presuming this is too much, right?
2. What's the recommended torque setting for Torx E14?
 

sikwan

06 Tin Can
1. If you can touch the compressor pulley, you need a new belt.
2. I don't know the torque setting off hand, so maybe around 40lbs.
 

cahaak

New member
Here is some follow up that may be helpful. I continue to use the 17385 belt (17 mm x 38.5"). Don't ask me how they came up with that system. As for squealing, I do not get that any more and my rear AC works great now after Dennis @ Linden evaced and recharged with the correct charge. So, a couple things to be aware of - system having the correct charge - and correct belt and tension. I just pull on the tensioning pulley by hand until tight and then tighten the bolt on it. (and mine is not an Etorx, but a 13 mm, so it must have been changed at some point). I have not touched my system in about 1 year and it continues to work great.

Chris
 

segler

2003 158" 3500 Class B RV
My 2003 3500 is a RV conversion with front and rear ac. Instead of rooftop evaporator, mine has the evaporator under the chassis to send cold air into the cabin from underneath. (This system also gets heat from an Espar Hydronic for cold weather use.)

The rear ac belt is a 17380. 17385 is too long--it does not tension fully.

The bolt on my idler pulley arm is a 19mm hex (3/4" socket works, too).

Everything works. What I don't like is the design that has the crankshaft pulley pulling power FIRST over the idler pulley instead of FIRST over the commpressor. This is why the idler has a fixed position instead being spring-loaded.
 

doug022984

Sporadic Member Since 2015
What I don't like is the design that has the crankshaft pulley pulling power FIRST over the idler pulley instead of FIRST over the commpressor. This is why the idler has a fixed position instead being spring-loaded.
So are you saying you have a second compressor driven by a separate belt from the main serpentine belt? If so, please provide pictures of your setup because I'm curious.

My understanding of the factory rear A/C is that it uses the same compressor as the front A/C and just has a valve that opens and closes to allow refrigerant to circulate through the rear circuit. The main A/C compressor is not as you describe. The crank pulley pulls directly on the A/C compressor. Attached is a view of the belt routing.

vic edit:
As this question was never answered...
There are 2 different T1N rear A/C compressor designs. The earlier design had a separate A/C compressor driven by a Vee belt off the Harmonic Balancer. The later design used the same serpentine belt driven A/C compressor for both front and rear A/C.
 

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