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chasfm11 · 12-31-2005, 12:04 PM

I have the belt in my hand and almost tackled the job today. Here is why I didn't:
1. I didn't shine a light up into the cavity but I couldn't figure out how to release the tension on the self-adjuster in order to get the belt off. I can feel it and move it but could figure out where the pivot point is to put the wrench, assuming that is the way it is done.
2. It appears that the belt is captive over the fan - meaning that I'd have to work the belt down over the fan blades before attempting to route it through the pullies.

I was hoping that someone else had a rear radiator DP like mine with an ISB and had done this replacement or been present when someone else did. To be honest, if it weren't for the problem of getting the belt over the fan, the job appears easier than putting a belt on my '89 Econoline van with the 351 engine. I've done that job several times and there just isn't a lot of room to work. On the ISB, I can easily trace the belt's route with one hand and it isn't as complicated as the van.

Thanks for any personal experience that you can relay to me.

Charlie

chasfm11 · 12-31-2005, 12:04 PM

I have the belt in my hand and almost tackled the job today. Here is why I didn't:
1. I didn't shine a light up into the cavity but I couldn't figure out how to release the tension on the self-adjuster in order to get the belt off. I can feel it and move it but could figure out where the pivot point is to put the wrench, assuming that is the way it is done.
2. It appears that the belt is captive over the fan - meaning that I'd have to work the belt down over the fan blades before attempting to route it through the pullies.

I was hoping that someone else had a rear radiator DP like mine with an ISB and had done this replacement or been present when someone else did. To be honest, if it weren't for the problem of getting the belt over the fan, the job appears easier than putting a belt on my '89 Econoline van with the 351 engine. I've done that job several times and there just isn't a lot of room to work. On the ISB, I can easily trace the belt's route with one hand and it isn't as complicated as the van.

Thanks for any personal experience that you can relay to me.

Charlie

Disneydaddy · 12-31-2005, 02:19 PM

I have done several of these belts on ISB but none on a DP. You are correct that the belt needs to go over the fan, thats the toughest part even with good access. Make sure and draw a diagram before removing the old belt, dont rely on memory.

Scott

chasfm11 · 12-31-2005, 03:31 PM

Thanks, Scott. I cheat these days and take digital pictures of things before I take them apart. It is pretty easy to get the camera close enough to see the whole belt track.

I wonder of the fan on the DP is larger than when the ISB is mounted in a truck. That is the only thing that has me concerned.

Renegades · 12-31-2005, 06:40 PM

Charlie,
Yes the belt will go over the fan pulley. You don't release tension as you think. If you can use a mirror or get a camera to look at the front of the tensioner, you will see a square opening for a 1/2 inch breaker bar. You insert the end into the opening and move the pulley to remove tension. Now holding the bar with one hand, reach up with the other and slide the belt off of the pully. Now release the bar slowly. Thread in the new belt. Once it is on all the pullys, your ready to reverse the process and put the belt back on the tensioner. That is all there is to it. Good luck. I had my belt come off on my cat and I had to replace it with a hot engine. Got a few burns, but nothing major.

Jim
RV Tech

chasfm11 · 12-31-2005, 06:57 PM

Thank you, Jim! That is just the information that I was looking for. My Econoline follows the process that you described but uses a hex head on the tensioner instead of the square breaker bar.

Maybe I'll tackle it tomorrow. I finished up the last of my other maintenance today. I just have the belts to replace and I want to splice hoses around the water pump to quiet it down. Then, I'm ready to hit the road again.

I appreciate your help.

Charlie

chasfm11 · 01-07-2006, 07:31 PM

I finally got the time to start the belt replacement today. In the nutshell, the engine belt is very easy to replace and I'll finish that tomorrow.

The bad news is that the A/C belt is a real PITA. None of my tools worked well on any of the compressor mount fasteners. When we finally got the locknut loose for the compressor adjustment rod, getting the belt off the pulleys was hard. Currently the belt is hung up over the fan blades - there is no way that a belt that length is going to clear them. I'm going to work the A/C belt back onto the inside of fan and over the pulleys tomorrow. Then, I'm going to take the old engine belt off and put the new engine belt on. After that, I'll re-install the old A/C belt. I'm headed to NAPA on Monday to replace the A/C belt that I purchased with one 2 " longer. The A/C belt that I got from Freightliner isn't "ribbed" on the bottom and that is probably nessary so I'm make sure I get that with the new belt. I can tolerate the additional length on the adjustment rod and those extra 2" are all that I need to get the belt over the fan blades.

Ah, the joys of a rear mounted radiator..... Actually, I think this is more of a problem with the aftermarket Evans package than GBM installed that the fact that the radiator is in the back. The engine belt by itself would be a "5 minute" job.

gMw · 01-11-2006, 05:08 PM

I don't know if your set up is exactly the same the one I had, Freightliner told me that the fan blade had to be removed to replace the ac belt. And Freightliner estimated three hours to remove the fan and replace the AC belt,

I ended up changing the belt myself and tried going with an 1 ½ larger belt, but no luck, it wouldn't go over the fan, so I removed the fan. The NAPA belt I used was part number25-9415. For what it's worth the belt Freightliner sold me wouldn't fit at all.

Good Luck

chasfm11 · 01-13-2006, 04:20 AM

Update: My new A/C belt is in place and working fine. I used NAPA 25 9420, a 42" belt. While it was tight over one of the fan blades, it did go. I would not recommend trying the change in cold weather if there is a choice because the fan blade had to flex a little. Rolling the belt inside out to take it over the fan helps a lot.

On mine:
1. The tensioner had been moved from its proper position. It should attach to a hole in the engine block, just under the compressor and the adjustment block should attach to the lower driver's side "ear" on the compressor. Mine was mounted under the compressor, sticking out toward the passenger side. I believe that this was done to allow the 40" belt to be installed.
It took a detailed diagram from Freightliner to help me figure this part out. There is plenty of adjustment range to handle the 42" belt and I strongly believe that the compressor mount was reengineered for that sized belt - the Freightliner records for my vehicle are just wrong.
2 There was also a point on the tensioner shaft that had damaged threads. My neighbor (an old cotton farmer) helped me work the threads through the block until the shaft would run freely end to end. I suspect this damage was done when the tensioner was repositioned.
3. The the compressor mount bolts are metric. A very deep 18mm socket was needed to break the locknut loose on my tensioner shaft - there wasn't room in the incorrect position to use a an open or box wrench. In the correct position, this isn't a problem.

It was not necessary to take the fan off. In another forum, it was suggested by someone who tried that there isn't sufficient clearnace between the fan bolts and Charge Air Cooler to do it.

With the tensioner in the correct position and able to adjust through the full range of the shaft, using a proper sized belt (42") and not having any of the misinformation that was passed to me regarding this change, I believe that I could have done both belts in under an hour without breaking a sweat. I believe that changing the belt on my '89 Econoline is more difficult. There were some funny things like a 3/8" square hole in the engine belt tensioner (I now have a 3/8" to 1/2" adaptor as part of my MH tool kit) but it not a difficult or mechanically challenging job if everything is set up correctly, at least on mine.

If anyone else is considering an ISB belt change and would like more information, please send me a private message and I'd be glad to help. I sure would hate to see anyone else go through what I did when it isn't necessary.

Charlie

I'm adding a picture of the correct A/C belt tensioner location

chasfm11 · 01-27-2006, 04:28 PM

I've been contacted by two other owners who were attempting to replace their belts. Both had the tensioner mounted under the compressor as I did, contrary to the Freightliner diagram.

The only commonality among our three units is Freightliner Custom Chassis and I believe that is where the tensioner was incorrectly installed. In addition, at least one of the others had shaft thread damage similar to mine.