Replacing an evaporator - some questions

[SailorMcCruise]

Hello to all friends of the famous fridge,

my boat had a converted-to-active-fridge ice-box which I had to demolish and remove due to a hull damage.
The system used a Danfoss BD-35 and a Veco E5247M evaporator.
The latter did not survive the removal and I was lucky to find a kind person on another boat to bring me a Dometic VD-07, which seemed to be a sensible replacement. ( Note: I am far away from convenient affordable online shopping possibilities for parts, let alone local shops with abundant merchandise ).
So now I do need to install the new evaporator and before I mess up, I need to make sure I understand the process.

As I understand it, the evaporator came preloaded with coolant and since the previous one had a punctured tube I assume that all the previous coolant must have leaked out of the system.
"
Is there the need to add more coolant? ( the only one available here is the standard stuff, that people use for their car aircons )

The manual tells me to to lubricate the connector threads with "ester oil" or "refrigerant oil". As I understand this is a synthetic oil as opposed to mineral ( WD-40 et. al. ). So synthetic motor / gearbox oild would work, I wonder?

How do I proceed after installation? I guess there might be the need to bleed out air out of the system, no?
Can I do this with household ( boathold, harhar ) tools or do I need a fabce vacuum pump?
The Danfoss has a tire-valve type connector.

Thanks for all help and info!

[fourlyons]

I don't know where you, are but most cars on the road now run R134a refrigerant, which is what your refer system almost certainly had. Look at your compressor, there should be a sticker somewhere identifying the refrigerant.
The new evaporator should come charged, but it sounds like your compressor/condensing unit may have lost it's charge. If so you will need a vacuum pump, no way around that. And not pulling a good vacuum before charging is going to cause a lot of problems, especially if you are in a humid climate and your system has been open for a bit. I really think you need to figure out the vacuum pump before going much further. Are there auto parts stores where you are, do they rent or sell vacuum pumps?

[SailorMcCruise]

Ok. Thanks. I shall enquire in the auto stores for now it seems.

[fourlyons]

Something else to consider, do you know for a fact that the quick disconnect fittings of the new evaporator match those on your compressor? Also, for the record, what you call a tire valve is a 1/4" Schader valve and is not what is used on cars, so you will need an adapter to use automotive charging hoses on your system.

[Quadrille in JB]

If the quick disconnectors are compatible you will definitely have to evacuate the system using a vacuum pump before charging. The little bit of oil on the O-rings shouldn’t make a big difference. You will need, at the minimum; a hose to transfer your Freon, R1 34 from the can to the quarter inch fitting after evacuating the system. You should really pressure test the system before charging it but in your case with the little bit of refrigerant being used, it’s not absolutely necessary. A set of HVAC gauges would be really helpful in this case.
After evacuating the system, slowly add the refrigerant with the compressor running. If you have a HVAC scale, add about 4 ounces. Without the scale, there are several options; very slowly charge until the frost completely covers the evaporator. Option two; if you have a DC clamp on ammeter you can charge system slowly until you’re drawing about 4 Amps. If the system shuts down you probably overcharged it and need to start over by removing some of the refrigerant. Option three; charge until you have about 3 to 4 psi in the system while it’s running. All of these charging options need to have the compressor running.
This is all doable, just be patient and good luck. This is not rocket science!
Quadrille in JB

[pcmm]

Originally Posted by fourlyons

Something else to consider, do you know for a fact that the quick disconnect fittings of the new evaporator match those on your compressor? Also, for the record, what you call a tire valve is a 1/4" Schader valve and is not what is used on cars, so you will need an adapter to use automotive charging hoses on your system.

The automotive kits DO fit the schrader valves on the BD-35 compressor (the larger auto quick connects just screwed onto the hose in the kit. Don't use those and it fits). I have recharged mine this way when my system was low. Having said that not all areas allow consumers to purchase R-134. Where I am (Canada) you have to be a licensed contractor to purchase it. So I order R-134 from amazon and picked it up in the states!

[SailorMcCruise]

Thanks all.
A lot of ground covered.
It seems that there is a person here who is willing to borrow me a vacuum pump.
The R134a can be had in a local hardware store, so I guess I should be fine.
I am pretty sure the connectors fit as well ( see images )
On a last note, just for the record: What is that "ester/refrigerant oil" supposed to be?

[pjShap]

Check the documentation for your compressor. My BD compressor emphasizes that the refrigerant should only be pure R-134A, without any leak stop, dye or oil. Most automotive refrigerant includes one or more of those.

[Bowdrie]

Originally Posted by SailorMcCruise

The manual tells me to to lubricate the connector threads with "ester oil" or "refrigerant oil". As I understand this is a synthetic oil as opposed to mineral ( WD-40 et. al. ). So synthetic motor / gearbox oild would work, I wonder?

Don't even think about any such things as WD-40 or any motor/gearbox oils.
Anybody in your neck-of-the-woods that does AC/refrigeration service will have the oil you want; you're only talking a small drop for each fitting if that, hardly a wipe with a fingertip on the threads.

[CrispyCringle]

I thought after a completely evacuated system you added refrigerant based on weight. They type refrigerant and ounces in the system should be on a data plate someplace on the unit.

[SailorMcCruise]

Hello,
I need to revisit this thread as I now found time again to tend to the fridge.
Unfortunately the connectors are not compatible ( see above image ) The Dometic VD-07 and the Frigoboat system do not agree ..
What can be done? Is it possible to make an adapter? Or add different connectors to the Frigoboat? I hope I dont have to buy a new system?

[fourlyons]

If you don't want to buy an evap with the correct connections, an option is to cut the connectors off and silver solder the lines together. You will need a propane torch, a tool to enlarge the tube to allow one tube to fit into the other, then solder. Or, the easiest is to cut the connectors off and join them with flare fittings. You will need a tubing cutter, a flairing tool, and a vacuum pump. You will need the pump no matter which way you go.

[Bowdrie]

Go here and see what you need.
Some time with a torch and you're back in business.
https://www.rparts.com/index.php?rt=...th=84_13_21_36

[SailorMcCruise]

Ok. Will see if I can get some of these or I shall just connect the tubes for good.
The Dometic version is also not supposed to come undone again without not sealing.