Community Forums

Kedwinh · 02-17-2025, 10:46 AM

Hello
Well I think I'm gonna do the belts and tensioner on our 2007 Bounder C7. Not real sure how it'll go but. Anyway, anything I should watch out for or trucks? It's a rear radiator so will doing it from above, and below.

Thanks
Keith

David 70 · 02-17-2025, 10:54 AM

Just make sure you have a diagram of the belt routing. You may think you can rmember but believe it gets confusing.

Flyer15015 · 02-17-2025, 10:55 AM

Heith,
I would do a deep dive into YouTube for the procedure.
Might save you a lot of cuts and bruises.

JMHO
Mike in Colorado

SafariBen · 02-17-2025, 01:40 PM

The serpentine belt is not bad. The water pump v belt is a real pain, IF you have the same V belt as a 3126, there are some tricks, but I can't remember, if you hit a roadblock, come back and search more or ask specifically. It's not terrible, but it gets terrible with less access, and less mechanical ability.

FIRE UP · 02-17-2025, 09:36 PM

Quote:

Originally Posted by Kedwinh

Hello
Well I think I'm gonna do the belts and tensioner on our 2007 Bounder C7. Not real sure how it'll go but. Anyway, anything I should watch out for or trucks? It's a rear radiator so will doing it from above, and below.

Thanks
Keith

Well Keith,
I kind-a just went through all this with our coach, an '04 Itasca Horizon 36GD with the CAT C-7 330HP. While the engine in yours and ours is for the most part, the exact same, what will be different is your bedroom layout and engine access. Below are pics of ours in various scenarios. The first and maybe the most important thing I can suggest here is, do whatever it takes to gain as much access to that engine as you can. Unbolt, unscrew, remove, disassemble everything that will help you gain the best access. Changing these two belts with the radiator and CAC out of the way is childs play.

But, changing them WITH the radiator and CAC still in place, and your only access is primarily from the top, well, that's almost murder. Is it doable? Well, a lot depends on a bunch of variables. For one, how limber are you? By variables I mean the angle of attack to place the 1/2" drive ratchet or breaker bar in the square 1/2" hole on the serpentine tensioner can be a bit of a chore. Then, once the tool is there, you need enough *pull* (since the direction you should be working from will or should be from up top) to pull on that breaker bar to relieve tension enough to remove the serpentine from either the alternator pulley or the idler pulley while still holding tension on that breaker bar or ratchet.

If your bedroom layout and or access is even similar to ours, you'll be almost hanging upside down while doing about 98.5% of this work. Then, THEN, getting that belt off while all the fan, fan shroud, and anything else is in the way, is another feat of work. The routing of it is no big deal. It's pretty simple. I'm also sending pics of your routing.

Once the Serpentine belts out of the way, now it's time to attack the water pump V-belt. The great part about this is, you're REALLY UPSIDE DOWN now! Due to the way Freightliner constructed the undercarriage, cross member, radiator hoses, transmission cooler etc. gaining access and doing just about ANY work on these two belts from under our coach is for the most part, totally impossible!

The water pump tensioner is attached with two fasteners. One isn't horrible to gain access to. The other, well, it's the one that gives all of us C-7 Pilots a serious run for the money. It's the one that is over the slot for adjustment. While that bolt head IS clearly visible, it's dang tough to actually put a tool on it and swing that tool to loosen, or tighten it when done. It has been suggested to watch some youtube vids on this. Well, yes you can see at least one. And it's made by the Adept Ape, a CAT tech that's pretty darn good with CAT stuff and help.

But, when he's doing this video on the C-7 Water pump, he's doing it WITH THE RADIATOR OUT AND his access is completely different than doing it in the dongeon of a radiator and CAC still in place. The good part about his video is it shows exactly where the placement of the bolt heads are. There is also a square 1/2" hole in that tensioner that is used for applying tension while tightening things up. But, again, the close proximity of the engine dampener and other pulleys AND THE V-BELT, along with BEING UPSIDE DOWN, sure put the heartache on high order here. I created my own square tool to apply tension on that water pump tensioner. It's got some small width webbing attached to it that when tension is applied from a distance, I can tie that webbing off on one of the radiator shroud support rods and that will hold that tension while I position my fat, old worn out body in position UPSIDE DOWN with the appropriate tool, to begin tightening the two fasteners.

Not a fun job, to say the least. Our bed has about a 12" high wall around the engine compartment that cannot be removed for the most part. I had to lay on the top edge of that wall while doing all of this work and I damaged a rib doing it. Needless to say, it hurt for a couple of weeks. Yeah, fun stuff.

Once the V-belt is in place, and the correct tension is applied and the fasteners are tight, then the replacement of the serpentine belt takes place. The routing of it isn't the end of the world other than the tip of the fan blades to the inner part of the shroud don't allow for much clearance. That belt is thin. But at least on our setup, it almost wasn't thin enough to ease its way between the fan tips and the shroud. Once it's all routed, you then have to lean way down hill, grab that breaker bar or ratchet and apply tension to that spring loaded tensioner enough to create jussssst enough slack to nudge that serpentine over either the idler or the alternator pulley. Again, not fun stuff.

I have done these two belts with the radiator and CAC out of the way and it's soooooooo much easier. But, it's a pretty fair amount of work to R & R those two units JUST to change belts. But, there's a reason for doing it that way. And that reason is to do A LOT of maintenance while in there. Radiator and CAC fin cleaning, tensioner (both) bearing replacement, belt replacement, hose and clamp check, serpentine idler bearing replacement, fan bearing check, etc. A lot gets done when that radiator and CAC are removed.

Anyway, I hope some of this can help with your approach to do this chore. Again, there's lots of variables like bedroom layout, access to the top and front of that C-7 in your particular coach and more. Good luck and don't hesitate to ask. Be glad to help.
Scott

SafariBen · 02-17-2025, 09:47 PM

If you take the radiator out, might as well do the front crank seal if there's any leakage at all.

d23haynes57 · 02-17-2025, 09:48 PM

When was the last time the radiator and charge air cooler was removed for cleaning. Have you been having cooling issues. I find the big serpentine belt often snaps around 50K and that depending on rad conditions that cooling effectiveness drops around the same time and owners go into denial or just keep fighting it. With the radiator and charger air cooler out belt and water pump access become easy. Time to do all the hoses and if any pipes are beginning to rust. I suggest 40K intervals to avoid the nuisance overheats and tow truck calls. Also check that the trans cooler is not filled with debris on the water side. Every other service, (90K) replace the water pump and tensioner also. Inspect/replace fan bearing as needed. Global Final charge coolant of choice.

FIRE UP · 02-17-2025, 09:50 PM

Here's a few more to maybe help. While the routing of the serpentine belt is seen and done on a clean and painted engine, the picture of the water pump tensioner is when that engine was in its dirty phase. You can clearly see the square hole in it and the fasteners. And, you can see the difficulty it's gonna be in obtaining access to those fasteners while the radiator is still in. By the way, there's a couple of points to make here on that water pump tensioner.

1. There's been a few reports on here from RV'ers that have attacked this water pump replacement or tensioner adjustment for belt replacement, have BROKEN at least one of the water pump V-belt tensioner bolts due to rusting in place. That's not a good thing at all. Take EXTREME CARE when loosening either of those tensioner fasteners.

2. When Adept Ape is doing that video, he does show TWO different placements of the one bolt in the slot. There's an upper hole and a lower hole for that slot bolt position. When I removed mine, it was in the lower one which made removal of it and tool access to it damn near impossible. But, upon cleaning that engine block, I found that second bolt UPPER bolt hole. I cleaned it all out, ran a tap through it and used it for application when tightening up the tensioner. Waaaaaaaaaay easier and more accessible than just an inch or two lower in the other hole.
*Scott

Kedwinh · 02-18-2025, 08:35 AM

WOW, thanks everyone. That's definitely a lot of information. I was pretty sure it wasn't going to be a cake walk to do it from above but there's considerably more than I was aware of. After reading your replies I believe dropping the radiator and CAC are the smart way to go, wouldn't hurt to have them cleaned and pressure checked anyway. So with that , and my age, I'll probably wait until we get over to my son-n- laws. Thanks again for the replies and pictures.
Keith

FIRE UP · 02-19-2025, 08:58 PM

Quote:

Originally Posted by Kedwinh

WOW, thanks everyone. That's definitely a lot of information. I was pretty sure it wasn't going to be a cake walk to do it from above but there's considerably more than I was aware of. After reading your replies I believe dropping the radiator and CAC are the smart way to go, wouldn't hurt to have them cleaned and pressure checked anyway. So with that , and my age, I'll probably wait until we get over to my son-n- laws. Thanks again for the replies and pictures.
Keith

Yes
Without a doubt, doing any belt or bearing work on any of the rotating accessories is considerably easier without having the radiator and CAC in the way. But, that's not to say getting that radiator and CAC out is gonna be easy. Again, like stated earlier, each coach builder, along with the chassis builder, don't make it easy to r & r those two components. You've got your work cut out for you either way.
Scott

the sights · 02-19-2025, 11:02 PM

I have done the full deep maintenance on our Freightliner chassis W/ Cat C7. That means removing and cleaning the radiator and CAC along with replacing all bearings, belts, hoses, coolant, Cat regulators (thermostats) and water pump.

On our last trip the alternator froze up and I had to change it at our site along with replacing the ripped fan belt. Hard to do but doable my arms are still scabbed up not a lot of room to work.

I have done it both ways if you do the full job meaning removing the Rad/CAC you can do all needed maintenance and I would include having your alternator rebuilt.

Its a lot of work to do the full job but just replacing a belt and 1 Belt Tensioner is only 10% of the work needed on a rear radiator coach.

Kedwinh · 02-20-2025, 07:25 AM

I had planned on doing the belts and tensioner along with having the radiator cleaned and pressure checked. Had also planned on the hoses while the radiator was out. I hadn't thought about the alternator but that's a good idea to.
Thanks again everyone

Cat · 02-20-2025, 06:32 PM

As mentioned check or replace the fan bearing. It is a known problem. If you do go for removing the radiator and aftercooler. I would absolutely put a new fan bearing in. Good luck let us know what you decide. Safe Travels

FIRE UP · 02-25-2025, 09:25 AM

Well Keith,
Just for info, our factory alternator lasted 116,000 miles and I'm pretty sure I'd still have it in there if *I* didn't cause it to fail. It's a long story but I won't go into it now. As for the fan bearing, it lasted I think, 87,000 miles and one of the times I had the radiator and CAC out I tested the original one and it still seemed just fine. But, I had all those other components out and figured, well, let's just replace it.

Now, with all that in mind, if you're going to replace that fan bearing, in my opinion, you better start collecting all the parts involved NOW! While there are some, if not most, CAT engine parts still readily available, I'd red on here and maybe a couple other sources, that the fan bearing is becoming scarce. I have a complete parts list somewhere and I'll try and find it for ya. But, that's what I'd do.
Scott