Removing the OTR AC on 64 GM 4106

andyps · February 20, 2018, 06:16:54 PM

Hi there, I am removing my OTR AC on my 1964 GM 4106. Im installing a mini split system, and I want to utilize the condenser bay for the outdoor unit (multi-zone unit) of the mini-split. So I am removing everything from that bay.

The cooling fan on the condenser coil/radiator is hydraulic. From reading the manual it seems like it's run from an engine driven hydraulic pump. Is that all that the pump drives? Am I safe to disconnect the fan motor and drain the system?

Anything else I should know when Im removing the AC lines and condenser coil?

luvrbus · February 20, 2018, 07:02:05 PM

On a 4106 the AC drives from a PTO off the Torus fan,but you can pull the drive and plate over it, the pump you are calling it (Torus drive) has to stay for the engine cooling fan, now the hyd part I never saw on a 4106 those were usually dc fan motors

andyps · February 21, 2018, 10:40:58 AM

Quote from: luvrbus on February 20, 2018, 07:02:05 PM
On a 4106 the AC drives from a PTO off the Torus fan,but you can pull the drive and plate over it, the pump you are calling it (Torus drive) has to stay for the engine cooling fan, now the hyd part I never saw on a 4106 those were usually dc fan motors

I don't think we're talking about the same thing. On my bus, my AC condenser coil cooling fan (the one in the front drivers side AC bay) is definitely a hydraulic fan, not a DC. I've already been in there to investigate and my manual confirms it. The schematic also shows the lines to that fan going to a pulley-driven hydraulic pump mounted to the side of the AC compressor in the engine bay. So it seems to me this is the pumps only purpose and I'm a-okay to remove and drain. Just wanted to double check in here to make sure.

Thanks

richard5933 · February 21, 2018, 10:57:10 AM

Where is the pump for this fan? I don't remember our 4106 having a hydraulic fan.Can you post a photo or two?

viking42 · February 21, 2018, 11:00:23 AM

Have a 62 gm 4106 also pulled standard air condition had large dc motor that circulated air for heating and air also had hyd motor that ran condenser or evaporator, just know it was large , never regreted it, left hole for lots of storage and generator, now heat from defrosters supply heat for bus down to 20 degrees, anything more i run generator an electric heat works quite well for us being snow birds helps hope this helps

richard5933 · February 21, 2018, 12:16:38 PM

I know a lot of people pull the OEM HVAC system for various reasons. I'd suggest if you're doing this is to make sure that whatever you're replacing it with can 1) be used on the road, and 2) will be able to keep up with the outside temps both summer and winter. Also, do what you can to preserve the coolant lines which run to the defroster along with the booster pump located in the front passenger-side compartment. You'll be glad you've got something to keep you toes warm and the windshield clear.

TomC · February 22, 2018, 05:58:10 PM

Running 2-13,500btu roof top A/C's going down the road works just fine keeping the inside of the bus at about 75. If need be, I can kick on the third, but two are usually all I need-powered with Powertech 10kw Diesel Generator. Good Luck TomC

RJ · February 23, 2018, 06:17:03 PM

Quote from: andyps on February 20, 2018, 06:16:54 PM
Hi there, I am removing my OTR AC on my 1964 GM 4106. Im installing a mini split system, and I want to utilize the condenser bay for the outdoor unit (multi-zone unit) of the mini-split. So I am removing everything from that bay.

Good use of space. Are you keeping the OTR heater?

The cooling fan on the condenser coil/radiator is hydraulic. From reading the manual it seems like it's run from an engine driven hydraulic pump. Is that all that the pump drives? Am I safe to disconnect the fan motor and drain the system?

Yes, the hydraulic pump next to the A/C compressor on the driver's side of the engine is only for the condenser cooling fan up front, so removing it is not an issue for what you're planning. The coach's power-assisted steering is handled by another pump on the alternator end of the 8V71.

Anything else I should know when Im removing the AC lines and condenser coil?

Lots of copper in than condenser coil - should be able to get some $$ for it at your local metal recycler.

Highly recommend that you keep the OTR heater - nothing can match it, or the defroster. Just be sure to clean the filter - it's located behind a door on the passenger side in the compartment between the RF wheel and the fuel filler.

BTW, what's the VIN on your coach? PD4106-XXXX? Jon Ulse is keeping a list of all the "surviving" 4106s, I can pass the info to him.

FWIW & HTH. . .

andyps · February 26, 2018, 11:23:23 PM

Quote from: RJ on February 23, 2018, 06:17:03 PM
Highly recommend that you keep the OTR heater - nothing can match it, or the defroster. Just be sure to clean the filter - it's located behind a door on the passenger side in the compartment between the RF wheel and the fuel filler.

BTW, what's the VIN on your coach? PD4106-XXXX? Jon Ulse is keeping a list of all the "surviving" 4106s, I can pass the info to him.

FWIW & HTH. . .

Hi RJ, thanks for the info. I was able to pull the condenser coil and fan today. Got the space ready for the mini split unit.

I am planning to keep the OTR heat since it's still in working condition. I'd love to keep the OTR air, but it's far to expensive for me to repair and maintain, and I would like a system that will cool the bus when it's parked, as we're going to use the bus as a guest room of sorts when it's not driving.

My bus VIN is PD4106-2522, but I think I'm already on the list!

Thanks all for the replies. Hopefully will make a post when I finish the mini split install.