[rube bonet]

I have got some more interest in the f800/ freightliner High Mount AC set ups, and noticed the used prices were still quite high.

These are current retail prices from Rocky Mountain Cummins...any cummins dealer in your area should be able to get them.

3930888 Water inlet (The big cast piece)------------166.91
3930820 Alt support mount---------------------------29.14
3920862 Alt brace (does not work with dodge outlet)--31.31
3978021 Belt tensioner------------------------------158.35
3921382 Belt tensioner bracket-----------------------42.47
3906697 Rec O ring-----------------------------------3.23


The high mount ac (i guess really a mid mount ac) uses a 95 f800 compressor and 22 si alternator. I used it in a 6bt Chevy to clear the frame rails, but it works great in a lot of different applications. The other advantage on a 4bt is that you can still use the front lower motor mount area.



You will still need a water inlet that matches your set up, also a pretty easy part to fab yourself. I also made a new tensioner bracket, but it would have been very simple to modify the stock part, it is just a chunk of flat 3/8 plate.


The alternator brace won't work with the dodge outlet (not with out trimming a LOT of meat off of it), so I sell a custom bracket that allows you to uses the oulet. You can also change the outlets to a straight up style, which also works well, better in many cases.

 

[legendman]

Great info, thanks for posting.
Will be calling Cummins Tuesday.

 

[Apittslife]

Kewl many thanks! This fixes My 4BT problem with putting AC on it

 

[ambulancechser]

curious as to the part number of the sanden AC compressor you usd...

 

[legendman]

Got prices on these parts from my local Cummins dealer
in Rocky Hill, CT

3930888 Water inlet (The big cast piece)------------188.61
3921382 Belt tensioner bracket-----------------------77.24
3906697 Rec O ring-----------------------------------3.23

Not sure why the big difference in prices, but still cheaper than some of the used setups out there

 

[legendman]

Also does anybody know if a 2nd gen Dodge A/C Compressor will work? I would have to order the high mount bracket direct from factory

 

[rube bonet]

The 2nd gen dodge one won't work. I don't remember the model compressor it was offhand, but the application I used was a 1995 Ford F800 with a 5.9, and IIRC it was bought from the dealership.

.

 

[trackspeeder]

Got prices on these parts from my local Cummins dealer
in Rocky Hill, CT

3930888 Water inlet (The big cast piece)------------188.61
3921382 Belt tensioner bracket-----------------------77.24
3906697 Rec O ring-----------------------------------3.23

Not sure why the big difference in prices, but still cheaper than some of the used setups out there

Thanks. I was going to call them this week.

 

[legendman]

The 2nd gen dodge one won't work.

Argh deal breaker for me just got a 2nd gen compressor, I will hack up my frame and reinforced after I get the compressor mounted.
I am not spending more money on another compressor

 

[oldroofer]

Is a vertical oil filter required, If so I will be needing one.

 

[odee1]

what belt are you guys running with the mid mount ford ac? Get ready to try to bolt the parts on and want to have the belt ready to go. thanks

 

[CaseyS]

OK, I'm going this same direction too in a Hummer H3 buildup (build thread coming soon). Picked up the following from Cummins Mid-South yesterday :

3930888 - bracket $158.13
3930820 - lower alt support $27.60
3920862 - upper alt arm $29.66
3930838 - tensioner bracket $40.05

Add $18.05 freight charge and taxes to the above.

Couple of questions :

1) It looks like I have a different tensioner bracket 3930838 vs 3921382. I noticed that the tensioner with this bracket has only about 10 deg of rotation before it contacts the front case. I may have a little bolt slop to shim it forward a tad. Are these two brackets different?

2) I have upper water outlet 3914409 which points straight up which should work well with this combo. No interference.

3) Lower water inlet I have 3903103 which points forward and down. This will interfere and not work. Is the 3916625 inlet which points straight to the passenger side the preferred/common part used in this combo?

4) Can someone confirm the 4474 sanden will work with the horizontal filter arrangement? I have seen conflicting information.

Edit : I just noticed I've been lurking here for 2 years before my first post. I've sponged up so much information from this site its not even funny.

 

[CaseyS]

The 3930888 bracket will not work with the horizontal filter arrangement. I'll post some pictures here once my post count allows.

For now I'm going with a custom bracket to mount my existing ac compressor up top and the alternator below. The alternator is slimmer than the ac compressor allowing it to squeeze in front of the filter in the traditional location. I'm mocking up an arrangement now which should keep everything below the valve cover height.

 

[CaseyS]

Reference pictures for the Freightliner bracket and the horizontal filter. This setup will not work.

 

[David Kennedy]

Rob,
Do you know what length belt this setup requires? I'm using the same combination you have, but the truck is 60 miles away from me, and I can't measure it.

 

[rube bonet]

Rob,
Do you know what length belt this setup requires? I'm using the same combination you have, but the truck is 60 miles away from me, and I can't measure it.

Sorry, but not offhand...I'll see if I can dig up it up.

 

[David Kennedy]

The setup I have looks to require a 67-inch belt. I am not thrilled by the amount of belt wrap this setup puts on the A/C compressor (I think it needs more)--but perhaps the 8-rib belt is enough to overcome the drag?

 

[David Kennedy]

67 inches is too short, but it should be less than 69.5 inches long. I'll post up when I find a belt we think fits well.

 

[rube bonet]

I couldn't look the belt number up, the truck it was in is currently in pieces with no belt in sight.

Are you running the belt like the f800? crank-tensioner-compressor-alt-water pump- fan? I was worried about the ac compressor wrap also; I considered routing over the waterpump first and moving the tensioner, but I really prefer the tensioner be last in line, and it wasn't that great of an improvement.

.

 

[jtamulonis]

I`ve got the same set-up that`s in your pictures. the belt routing is: crank, A/C compressor, water pump, alternator, fan hub, the tensioner is under the A/C just like the pics. the kit I got came with a cummins belt #3289886. and the belt is a little too long. I dug up a dayco gold label #5080825 and it will just slip over the water pump with the tensioner all the way loostened. the A/C , alt, and water pump all have 180 degree wrap. I`m putting this on my VE pumped `99 24v. I think I`m using a `96 fan hub and damper. that may be why the cummins belt is a tad long.