TimSpencer

An electric compressor could be used. Without matching it to the metering device and coil it would not work properly. Matching the btu output of the belt driven compressor would be the best option. An inverter driven compressor or better yet condensing unit(compressor and condenser coil) would be even better. Controlling all this would take a few minutes to get working correctly. The engine driven compressor is not perfect but it is well designed and already controlled. Replacing refrigerant hoses is not fun or particularly easy but it is a far cry easier than redesigning the coach hvac system. Maybe trying to package a system like this in the dash area would be a better option. This would eliminate/replace the current system. https://www.supplyhouse.com/Sanyo-26UHW72R-24000-BTU-Single-Zone-Mini-Split-Concealed-Duct-Heat-Pump-Air-Conditioner

It is all dependent on what you are willing to live with. If you look through a Sanden compressor catalog you will see compressors with even higher capacities. I would imagine automotive systems are designed for very quick recovery which requires more BTU capacity. No one wants to wait an hour for their vehicle to cool down on a short drive. I was matching the most likely capacity of the existing compressor. You can find many 12vdc compressors with reduced capacity. Try Rigid Hvac and condensing units. Not a big issue to build just not the most cost effective. https://www.rigidhvac.com

A typical automotive A/C compressor is between 3-5 tons of cooling. Motor home application may be even higher. The compressor would need a40-60A AC circuit and the generator would need to be capable of double to triple that capacity for the in rush starting capacity. Using an inverter type condensing unit would be a conversion but would also require the indoor fan coil as well. No always the nicest look. I would guess the replacement of the refrigerant hoses would be a much simpler and cheaper option

You can try this. A little thicker and sticks to everything. https://www.amazon.com/Shurtape-ShurMASTIC-Outdoor-181B-FX-111163/dp/B01M6ZV9BA/ref=mp_s_a_1_3?adgrpid=66119376617&gclid=EAIaIQobChMIkZ7Jt5-0-wIV5hvUAR1VVQNzEAAYASAAEgJ-m_D_BwE&hvadid=617070353227&hvdev=m&hvlocphy=9009922&hvnetw=g&hvqmt=e&hvrand=16469413572864729902&hvtargid=kwd-355527657505&hydadcr=12190_13376095&keywords=butyl+foil+tape&qid=1668654796&sr=8-3

Good to know the sequence of operation. I would add a small electric fan for the condenser to prevent “forgetting” to shut off the dash air. Could be triggered by the radiator temp or just on when A/C is one. Great to hear you located and fixed all your refrigerant leaks. To bad you had to replace the compressor.

If you have room to operate you could use a torque wrench like this. But most mechanics would tighten by feel. https://www.amazon.com/VANPO-Adjustable-Accuracy-Indicator-Torquing/dp/B09XKCJD1T/ref=mp_s_a_1_2_sspa?content-id=amzn1.sym.a6428403-8a18-479d-9f6e-31f0b2c26f13%3Aamzn1.sym.a6428403-8a18-479d-9f6e-31f0b2c26f13&keywords=hvac+torque+wrench&pd_rd_r=8b778c08-7b15-4d9f-ba13-7b4cb1460a34&pd_rd_w=SGd20&pd_rd_wg=UrzVN&pf_rd_p=a6428403-8a18-479d-9f6e-31f0b2c26f13&pf_rd_r=E3QS8GT8N49TM365690N&qid=1667830107&sr=8-2-spons&psc=1

The above mentioned product is a great product and works well. I use Loctite 515 on o-rings on large equipment, recommended by Trane for all o-rings. It can be problematic on threads as it’s anaerobic and locks up like glass without oxygen. As long as the fittings aren’t damaged a new correct sized o-ring with assembly lube should be leak free. Inspect everything before reassembly.

I would do exactly what the last couple posters suggested. Top off the charge if leak is small and frequency to top charge doesn’t increase dramatically. Taking into account that it will leak while in storage or on the road.

David has it correct. Lots of variables depending on the designer of the system but automotive and RV systems are fairly basic. Receiver/drier has to be on the liquid line as it stores a bit of excess refrigerant and filters the refrigerant. Liquid is metered through the expansion valve into the evaporator. The liquid is vaporized lowering its pressure and it then can absorb heat from the air coming across the coil. This vapor then returns to the compressor. The compressor compresses the gas raises its pressure and corresponding temperature. This hot gas is then sent to the condenser where the heat is transferred to the air coming across the condenser coil and condenses the gas back to a liquid. And the cycle repeats. Line sizes in automotive systems can be tricky as the rubber hose outside dimensions don’t always give an idea of the actual inside dimension. But at the compressor the larger “cooler” line is the suction line from the leaving side of the evaporator the liquid line from the condenser to the expansion valve/evaporator is much smaller and the discharge”hot” line from the compressor to the condenser will be somewhere in between the suction and liquid lines. I’ll look for a pic to show a refrigeration system.

Most automotive systems use a low pressure switch only. A high pressure switch could be helpful but not always installed

Moisture is the toughest thing to remove from A/C systems. This is why nearly all systems include a filter/drier. Nitrogen can help to dry systems. But sometimes it takes a couple times of alternating nitrogen the deep vacuum. Anything that holds or attracts moisture should be avoided if possible. It seems these systems get neglected since there are alternative cooling systems. I have not used this brand but it’s very similar to the Calgon setup I use. https://www.amazon.com/HVAC-Guys-System-Flush-Refrigerant-Based/dp/B09XG6X77M

Alcohol is not the “best” line flushing agent. It can attract water. There are line flushing chemicals available that do a better job. Be sure to disconnect or bypass the metering device and compressor before flushing and always blow out flushing chemicals with nitrogen. Always use nitrogen to pressurize and leak check as well. Take some time to leak check it will pay off in the long run.

Most compressors have an internal relief. If discharge pressure is to high it bypasses to the low side. Makes an odd whoosh noise. Hoses can definitely leak. Soap bubbles, refrigerant detector, dye, etc can be used

Easier and cleaner. Take a couple days to get. https://www.amazon.com/Qagea-77750-Filter-Cutter-Cutting/dp/B09XQFM4M8/ref=mp_s_a_1_5?crid=2CMATCOXS240B&keywords=oil+filter+cutter+tool&qid=1666306579&qu=eyJxc2MiOiI0LjQ1IiwicXNhIjoiNC4zMSIsInFzcCI6IjQuMjYifQ%3D%3D&sprefix=oil+filter+cutt%2Caps%2C165&sr=8-5

Lots of variables. Easy button remove refrigerant then add factory recommended charge. Check pressures and temps and sight glass if equipped. Add refrigerant to clear glass. If everything else in the system is working then you should be good and it will be cooling properly. If pressures are not where they should be then further troubleshooting will be needed. I would guess the A/C system designer got it close enough to work correctly, nothing is perfect always some compromise

Not the best way. You can look at system pressures and temp to get a better idea of the charge on any refrigeration system. “Bleeding” refrigerant is just a waste of expensive refrigerant. Definitely looks overheated and contaminated for sure. Kind of the chicken or the egg. Did heat deteriorate the oil first or did the dye break the oil down. More likely high temp/pressure or low refrigerant charge(from leak) oil not returning from evaporator and compressor running out of oil and burning the small amount of oil left(my first guess)

I’m not a fan of dye but searching all portions of the system is vital. By any means. Dye, leak detection meter, etc.

Definitely could have happened. Relays and any set of contacts can fail in a million ways. From the contact melting, dislodging from the holder, bug between the two contacts, moisture, dirt,(I have experienced all of these and a couple other odd failures over the 3 decades of work with this type of relay and many larger types). Great job tracking it down especially since it was intermittent. These things wear out so good to have some good spares.

It looks like normal wear. Unless this relay is only been in use for a short time. If relatively new increase the amp rating of the new relay. Every time it opens/closes there is a bit of lightning bolt as the contacts approach each other. A bit of a welding arc. Eventually the contacts pit any can shed tiny metal droplets. Nice work tracking it down. I always have a couple of those relays in my spares.

If you have 110# and you jump low pressure switch, it’s a bad switch.

That sounds possible and would be a heck of a lot simpler.

I would try to buy engine with its original ecm, rewire as needed. Radiator maybe something that is a wait and see. I would definitely send it out for cleaning and pressure testing and if shop feels there is an issue then upgrade.

Not having made this particular engine swap but having done several others in my life. If the engine can physically be attached to the trans and chassis the hard part is done. Now assuming you have everything needed to run the engine (ecu, fuel system, exhaust, etc) you just as Monaco did will need to sort the wiring. Original wiring print and new print. All the connectors should be available if a conversion harness is easier or you can depin your original connectors. Sorting through the wiring prints can be done well ahead of time. As far as can the trans take the extra power and torque only Allison or time can tell. I think we all would like to know how it works. Good luck

You can try adding a pan treatment tab to help with cold water slime build up. https://www.amazon.com/Nu-Calgon-4296-60-Pan-Treat-Scum-Tablets/dp/B003N5AS60/ref=mp_s_a_1_8?keywords=a%2Fc+pan+tabs&qid=1662666702&sr=8-8

Everyone has now graduated to HVAC specialists. Great job on both coaches.