Automotive Air Conditioning Information Forum (Archives)

Toddc72 on Mon June 04, 2012 6:15 PM

Year: 2001
Make: Travel Supreme
Model: Motor Home
Refrigerant Type: R134a
Country of Origin: United States

Tim or anybody have any specs on this? All I found while looking around on it was it has a R134a sticker but no info printed on it. Amount of refrigerant needed or anything. Was going to add some to it to see about bringing the temps down a little cooler. Big vehicle to cool so I know it probably not going to cool it down a lot. My boss just complains it doesn't seem to blow cold air like when I redid his Chevy truck or his Ford. Thanks to Tim and the guys for the help and parts on those vehicles. This will be first time doing anything on this vehicle since he bought it last year. Any idea on pressures to look for? I will have to hook my gauges up to it and see what it has currently, but probably not get a chance till this weekend. Forgot to add this is a 38 footer in length.

Thanks

Edited: Mon June 04, 2012 at 6:16 PM by Toddc72

TRB on Mon June 04, 2012 9:41 PM

Pressures are always pretty much the same depending on if a vehicle is a CCOT or expansion device system. My data does not cover Motor Homes.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

NickD on Tue June 05, 2012 5:49 AM

With mine, got bounced back and forth between Chevy and Pace Arrow for even a basic refrigerant and electrical circuit. Let alone any information about charging.
On mine the evaporator and its housing was custom made, no manufacturer or name on it, no one at Pace Arrow knew who made it. So took it apart, leak tested it, and cleaned it. Also a dual fan blower motor, never seen one like that before, so took that apart, cleaned it and checked the brushes. Blower control was with nichrome resistors on a board, that was easy enough.

Compressor was a York, least found information on that, uses an expansion valve with an evaporator capillary tube that was shot, couldn't even find one close to it anywhere, again no name nor manufacturer. So I designed one using diodes for a temperature sensor, knew I wanted to kick it off at 33*F and back on again at 39*F.

Climate control looked like GM, but never saw a climate control with all spade lugs on it rather than a multi-pin connector. Someone got in there and screwed it all up. Took it all apart, cleaned the switches and the vacuum switch and made a circuit diagram of it so it could be wired properly. Knew at Max, the recir door should be close, air out the defrost vents in defrost, out the floor vents in normal, out the dash vents in Vent. Found hornet nests everywhere, so added screens, was blocking the mode doors from operating properly. Found those in the range vent as well and behind the refrigerator, cleaned up all that and added screens, replaced all the top vents, weren't sealing properly.

With an R-12 system charged to 29 psi at 85*F, high side was showing at 220 psi. Been seven years ago, think it took around seven pounds.

Its only a 27 footer but gets darn hot if sitting in the hot sun on pavement. To keep my girls happy, when starting off, switch on the generator and use the overhead AC to cool it down for about ten minutes. Then after rolling for awhile, say its too cold. This uses a variable heater valve with a slow delay time, so have to play with that to add heat to keep them happy.

Never heard about your motorhome, name doesn't make much difference, what chassis is it on, and what kind of components does it use?

bohica2xo on Tue June 05, 2012 1:42 PM

Todd:

Need some more information on the unit. Motorhome companies change names & models on a whim.

Which end is the engine in?

Compressor make & model?

Where is the condensor located?

Where is the dryer located?
.

From there we can make some educated guesses about the system from past experiences.

B.



-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Toddc72 on Tue June 05, 2012 5:57 PM

B.

Pusher engine layout on chassis. Chassis is Spartan Mfg.

Compressor has: Tama Mfg. on it with a Model number of J-639

Condenser is located in front of left front tire

Evap core says: Evans on it with a part number of RV200532 and is located a little to the left of center line on the front of the firewall

Accu Dryer is located a little to the right of the center line on the firewall below the condenser

Evap and Dryer locations are located when staring at the front of the firewall looking towards the back direction

Hope this helps some?

Thanks



Edited: Tue June 05, 2012 at 6:00 PM by Toddc72

NickD on Wed June 06, 2012 4:36 AM

Something like this?



A bit too much for me, I am getting old, with the compressor way at the rear powered by a Cummins diesel with line running clear to the front to the condenser, then to the evaporator, then clear back to the compressor with either a receiver or an accumulator stuck some place. Where are the service ports?

If it is low on refrigerant, looking at approximately 80 feet of line where anywhere can be a leak. That motorhome is sitting very low, can you even jack it up?

Then you say its for your boss, is this the guy you depend upon for a living? Are you experienced with MVAC? Call my wife the boss, she loves that since she was from Venezuela from a very male dominated society and was treated like a slave. She always wanted a motorhome, so we got one. Seen homes like that, I have a 30 by 15 foot level concrete slab on the side of my garage and a four ton 24" floor jack. That 27 footer has a gross vehicle weight of 12,000 pounds, I can handle that. Put douglas fir blocks under all six wheels so I could lift it to drop the AT that needed to be rebuilt. Sure couldn't handle this.

Is a King's Camper in Wausau, they have a huge shop with a gigantic lift for these big things, a bit too much for me to do the work myself.

We saw a 42 footer she like, king size bed at the rear, a laundry room with a washer and a dryer, side pull outs. Just said, we are lucky just to go out for weekend, a week at most, I can't handle that, not even enough space to park it. A man has got to know his limitations and these motorhome people charge 100-125 bucks per hour!

Are you sure you can handle this?

bohica2xo on Thu June 07, 2012 1:40 PM

Quote
Originally posted by: Toddc72
B.



Pusher engine layout on chassis. Chassis is Spartan Mfg.




Ok, good place to start. Pushers with long lines have their own pitfalls. Lucky for you, this one is still cooling somewhat.

Quote
Originally posted by: Toddc72


Compressor has: Tama Mfg. on it with a Model number of J-639



Tama / seltec compressor. J-639 is a specifiction, not a model number. An assumption is this is a TM16 compressor on a vehicle that big - but it could be the larger 31HD. Is the compressor mostly round, or is it more square?

Quote
Originally posted by: Toddc72

Condenser is located in front of left front tire


Ok, side sucker. All the way up front? Wow, long high side line from the compressor to the condensor. Do the fan(s) work when the compressor is running? Have you cleaned the condensor?


Quote
Originally posted by: Toddc72

Accu Dryer is located a little to the right of the center line on the firewall below the condenser


Uh, dryer is on firewall but condensor is in front of the front axle? I must be missing something. Anyway the dryer in the liquid line indicates a TXV someplace in the system, most likely inside the evaporator case.

Quote
Originally posted by: Toddc72

Evap and Dryer locations are located when staring at the front of the firewall looking towards the back direction



Hope this helps some?



Thanks


Oil return / oil charge is usually where the pushers have troubles. Undercharged systems can aggravate that failure, and with car systems getting smaller every year several pounds of refrigerant does not sound right to the average tech.

The proper thing to do would be to recover the system & weigh the charge. Then remove the compressor, drain & measure the oil in the sump. Finally remove the dryer, drill a hole in it and drain & measure the oil in it.

Once you know where the oil is & how much is there you can make any needed adjustments. The dryer is due for replacement on a system that big anyway.


If the service ports are way back at the compressor, don't be shocked at somewhat elevated suction pressures. Try to load as much liquid charge as you can in to the system through the high side port before you start the engine. Easy to starve a compressor on startup with those long lines.

I like to drain dryers overnight, then fill the new unit with what came out plus 2 ounces on those big systems. Refill the compressor sump with whatever the mfg spec is for that compressor & re-install it.

Charge. Totally seat of the pants. Hopefully you can see the sightglass on the dryer - a flashlight & mirror can help. I usually look for about 2.4 times ambient on the compressor discharge pressure with the engine @ 1500 rpm & the cabin fan on highest speed.

All systems leak, and those big ones just have more places to leak. Add some dye to the fresh oil. Recheck the system after a trip with a good blacklight. A 2001 with weak A/C is probably just attrition losses.

B.



-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Toddc72 on Fri June 08, 2012 2:58 AM

Quote
Originally posted by: NickD
Something like this? That is the one.







A bit too much for me, I am getting old, with the compressor way at the rear powered by a Cummins diesel with line running clear to the front to the condenser, then to the evaporator, then clear back to the compressor with either a receiver or an accumulator stuck some place. Where are the service ports?
Receiver is on the firewall in your face when you open the front section for access to everything. Condenser is located down low in front of left front tire. Service ports are dead center of firewall right as you open the front section and climb inside.




If it is low on refrigerant, looking at approximately 80 feet of line where anywhere can be a leak. That motorhome is sitting very low, can you even jack it up?
Trust me. This thing is not fun to work on because how low it sitting. Have done a ton of work on this thing with wire and what not from the front all the way to the back. Barely enough room under the basement area and the ground when normal ride height. We did figure something out later that helped. We stuck 7 inches of blocks under the leveling rams and raised it up. I had 15 ton jackstands for the back and we blocked under the front crossmember on the front. Has independant front suspension on it.



Then you say its for your boss, is this the guy you depend upon for a living? Are you experienced with MVAC? Call my wife the boss, she loves that since she was from Venezuela from a very male dominated society and was treated like a slave. She always wanted a motorhome, so we got one. Seen homes like that, I have a 30 by 15 foot level concrete slab on the side of my garage and a four ton 24" floor jack. That 27 footer has a gross vehicle weight of 12,000 pounds, I can handle that. Put douglas fir blocks under all six wheels so I could lift it to drop the AT that needed to be rebuilt. Sure couldn't handle this.



Is a King's Camper in Wausau, they have a huge shop with a gigantic lift for these big things, a bit too much for me to do the work myself.



We saw a 42 footer she like, king size bed at the rear, a laundry room with a washer and a dryer, side pull outs. Just said, we are lucky just to go out for weekend, a week at most, I can't handle that, not even enough space to park it. A man has got to know his limitations and these motorhome people charge 100-125 bucks per hour!



Are you sure you can handle this?

We are just wondering if it is ok on what we getting for temps and if questionable I am going to hook the gauges up to it. This makes the third vehicle I have done and the largest with 3 standard vehicles possible afterwards. Boss loves how cold I got his trucks after repairing A/C system on them. Sounds like that we may not be able to get the same kind of performance because of the line distance and the size of the vehicle on his RV

Toddc72 on Fri June 08, 2012 3:14 AM

Quote
Originally posted by: bohica2xo
Quote
Originally posted by: Toddc72
B.







Pusher engine layout on chassis. Chassis is Spartan Mfg.









Ok, good place to start. Pushers with long lines have their own pitfalls. Lucky for you, this one is still cooling somewhat.



Quote
Originally posted by: Toddc72




Compressor has: Tama Mfg. on it with a Model number of J-639







Tama / seltec compressor. J-639 is a specifiction, not a model number. An assumption is this is a TM16 compressor on a vehicle that big - but it could be the larger 31HD. Is the compressor mostly round, or is it more square?
Mainly round. Will have to compare with the specs on AMA site.



Quote
Originally posted by: Toddc72


Condenser is located in front of left front tire





Ok, side sucker. All the way up front? Wow, long high side line from the compressor to the condensor. Do the fan(s) work when the compressor is running? Have you cleaned the condensor?
Single fan on condensor and I checked to make sure no debri or anything was wedge into the condensor coils.






Quote
Originally posted by: Toddc72


Accu Dryer is located a little to the right of the center line on the firewall below the condenser





Uh, dryer is on firewall but condensor is in front of the front axle? I must be missing something. Anyway the dryer in the liquid line indicates a TXV someplace in the system, most likely inside the evaporator case.
Yes. Dryer is on the firewall dead center. Facing front of coach looking towards the back of motorhome on the firewall. You have upper left corner is evap and heater core in one. Middle of firewall is where dryer and service ports are. Right corner lower is where the condenser is in front of left front tire. TXV valve is attached to the evap core and covered with what looks like mastic roofing compound.



Quote
Originally posted by: Toddc72


Evap and Dryer locations are located when staring at the front of the firewall looking towards the back direction







Hope this helps some?







Thanks





Oil return / oil charge is usually where the pushers have troubles. Undercharged systems can aggravate that failure, and with car systems getting smaller every year several pounds of refrigerant does not sound right to the average tech.



The proper thing to do would be to recover the system & weigh the charge. Then remove the compressor, drain & measure the oil in the sump. Finally remove the dryer, drill a hole in it and drain & measure the oil in it.



Once you know where the oil is & how much is there you can make any needed adjustments. The dryer is due for replacement on a system that big anyway.





If the service ports are way back at the compressor, don't be shocked at somewhat elevated suction pressures. Try to load as much liquid charge as you can in to the system through the high side port before you start the engine. Easy to starve a compressor on startup with those long lines.



I like to drain dryers overnight, then fill the new unit with what came out plus 2 ounces on those big systems. Refill the compressor sump with whatever the mfg spec is for that compressor & re-install it.



Charge. Totally seat of the pants. Hopefully you can see the sightglass on the dryer - a flashlight & mirror can help. I usually look for about 2.4 times ambient on the compressor discharge pressure with the engine @ 1500 rpm & the cabin fan on highest speed.



All systems leak, and those big ones just have more places to leak. Add some dye to the fresh oil. Recheck the system after a trip with a good blacklight. A 2001 with weak A/C is probably just attrition losses.



B.

We are going to check the system better this weekend. We checked it on vent temps and outside temps but was pretty much meaningless because how cold it was outside. Supposed to be low to mid 80's this weekend. Joys of living in the mountains and cold temps trying to do A/C work do not go well together.



Edited: Fri June 08, 2012 at 3:16 AM by Toddc72

NickD on Fri June 08, 2012 6:49 AM

EPA had a paper on R-134a refrigerant loss per year kind of requesting, certainly not demanding that manufacturers do a little better job to reduce leaks.

Their paper stated an average annual loss of refrigerant of 10% for passenger vehicle and up to 50% for commercial vehicles! R-134a ports, whoever approved of them should be shot, a major cause of refrigerant loss. But done to please the manufacturers so they can use a quick coupler rather than take two extra seconds and screw one on.

In general, after checking over the entire system for any oil leaks, I mean this vehicle is already eleven years so refrigerant loss can be major. If no detectable oil leaks any where, just top it off by pressures. This can be done without knowing the capacity.

Just did that with my 88 Supra I had in storage for the last eight years, AC worked, never was charged before, checked it over for any refrigerant and oil leaks, found none. So added about 5 ounces of R-12 to top it off. Could never find 5/8's ounce leakage per year, but will keep an eye on it. Only 24 ounce system to start with so running at 80% can make a substantial difference in cooling. It did, blasting out ice cold air now.

But if I found oil leaks, would mean recovering finding the repairing the leak, a complete flush and adding the correct amount of oil. But I already know how much oil it should take.

Oil is the problem, and something you should know in advance. Could try calling:


Travel Supreme

66149 SR 19
Wakarusa, IN 46573
Local: 574-862-4484

And perhaps somebody there knows. Didn't have that luck with Pace Arrow, but you could be lucky. Let us know how you make out.

rojeho on Fri June 08, 2012 7:11 AM

I'm not going to be any help on the AC repair, but maybe the motorhome part. I don't know how much RV experience the owner has. It is pretty well known that the class C motorhomes - the ones that are GM/Ford van based - have a usable "dash" AC system, because they are good OEM systems. In class A's, whether gas or diesel, the dash AC is a joke, for many of the resasons already described (length of plumbing, oddball parts, inadequate and poorly located vents). The volume of interior space and glass makes the systems useless. I don't know if I ever used mine, and I was not alone. Running down the road in the summer, the generator was on and the roof AC's were used for cooling.

NickD on Fri June 08, 2012 12:48 PM

This is the AC/heater box in my 27 foot Pace Arrow, works very well, even on those zero degree days we get up here. But rarely gets above the 90's.





Box is 18" across to give you the idea of its size.

Who made this box and what heater core or evaporator is in there? Don't ask me. Won't worry about that until it breaks.