Grunert R12 Fridge Compressor

[Bermuda Forte]

Grunert compressor - engine driven R12
Yesterday I heard a pop and a screeching sound after firing up and running the the fridge for the first time this year. The compressor is a Tama Mfg J639 and it’s 20+ years old. Is there a recommended replacement and can I change now to a 134A compressor. Any advice very much appreciated.

[Coolerking]

Sanden 505 , Google that and see what you find.
Make sure you pay attention to the fittings and belts you have on your hoses and select accordingly.
If you switch to 134a, you will need to flush the lines and the plates to remove the oil.
You could also use a direct r12 replacement.
Like hot Shot 2, 417c.
How is the rest of the system?
Do you see the Filter drier, txv's, receiver panel and sight glass?

[Richard Kollmann]

This is an auto air conditioning compressor available from auto parts stores. It has a conventional mount but what may may it difficult to replace is the duel belt drive and type line connectors. Normally these compressors are referenced by make and model year of automobile. So the only way to get a matching replacement is remove it seal up hoses and take it to a AC parts dealer.

Seeing one good belt and one destroyed belt on pulley makes me wonder if there are two crankshaft pulleys driving compressor or the second failed belt is driving a second component that is what is causing your problem.

Grunert engine drive compressor installations do fail because of their excessive speed during clutch in gagement.

[Richard Kollmann]

Originally Posted by Richard Kollmann

This is an auto air conditioning compressor available from auto parts stores. It has a conventional mount but what may may it difficult to replace is the duel belt drive and type line connectors. Normally these compressors are referenced by make and model year of automobile. So the only way to get a matching replacement is remove it seal up hoses and take it to a AC parts dealer.

Seeing one good belt and one destroyed belt on pulley makes me wonder if there are two crankshaft pulleys driving compressor or the second failed belt is driving a second component that is what is causing your problem.

Grunert engine drive compressor installations do fail because of their excessive speed during clutch in gagement.

There are two good reasons for taking old compressor with you. There are two different compressor lengths you want the one that fits the mounting bracket. Next the hose connections are either Flared fittings or Orings so again match new to old.
Before removing compressor confirm there is a failure inside compressor by first having engine stopped and power to compressor OFF. Then place palm of hand against center of pulley clutch and see if it can be turned smoothly there will be friction to over pressure but not noisy. Next without removing compressor loosen belts and turn pulley to eliminate a clutch bearing failure. Without the belts and no power to clutch coil pulley should spin freely. This type clutch bearing can be changed without loss of refrigerant or removing compressor.

[Bermuda Forte]

Thanks for the tips. I’ll be without a fridge ‘till I figure this out.

[Bermuda Forte]

All of the Grunert engine driven fridge components are 30+ years old and had to come out as I’m reworking the engine compartment. Question now is should I forget the engine driven system and buy a 12v compressor, which one, and could I use the existing built in holding plates that were probably original to the boat (1963). I like the looks of these compact air cooled units like SeaFrost but it seems like everyone says ditch the old holding plates and go with these new evaporator plates, precharged with 134A, and DIY friendly. But ripping apart the fridge box to remove these massively built-in holding plates would be some task. The old arrangement had two sets of tubes; one was engine driven and another 12v. (Long gone). When the engine driven system was working last year, it seemed to work well but really only chilled the plate on the freezer side (although it never did freeze, the plate did). The box has 2 sections, about 1/3 freezer and 2/3 fridge, maybe 5 cubic feet total. All Hinckley built stainless steel inside. Suggestions?

[Bowdrie]

Originally Posted by Bermuda Forte

All of the Grunert engine driven fridge components are 30+ years old and had to come out as I’m reworking the engine compartment. Question now is should I forget the engine driven system and buy a 12v compressor, which one, and could I use the existing built in holding plates that were probably original to the boat (1963). I like the looks of these compact air cooled units like SeaFrost but it seems like everyone says ditch the old holding plates and go with these new evaporator plates, precharged with 134A, and DIY friendly. But ripping apart the fridge box to remove these massively built-in holding plates would be some task. The old arrangement had two sets of tubes; one was engine driven and another 12v. (Long gone). When the engine driven system was working last year, it seemed to work well but really only chilled the plate on the freezer side (although it never did freeze, the plate did). The box has 2 sections, about 1/3 freezer and 2/3 fridge, maybe 5 cubic feet total. All Hinckley built stainless steel inside. Suggestions?

I might think twice, perhaps thrice, before I chucked out all of the old system.
IIRC Grunert was not in business when your boat was built in '63, but that is of little concern.
The checking-out tests that Richard posted are valid, but those automotive based compressors are easy and not that expensive to just get a new one.
Any of the 12V pre-packaged units are ~1/6th HP, your compressor, (depending upon several parameters,) will have ~1.5>3HP, 2HP at conservative operation for freezer application.
Most, (if not all,) of the rest of the system is probably "off the shelf" stuff that is still obtainable, (Lots of engine drive systems were built with "Sendure" oil coolers as condenser usage,) and receivers/filter-driers/valves, are commonplace.
The more-or-less typical 12V unit that's running well in a properly insulated box will have a duty cycle over a 24 hr. period of ~12 hrs., so ~50%.
The 12V unit has ~1/6HP and runs for ~12 hours a day.
With a good box and properly sized cold plates the engine drive unit will do with its 2HP. in ~1 hour per day.
You'll notice that the end result is ~more/less the same.
The 1/6HP 12V unit ran for 12 hours=2HP.
The engine unit ran for 1 hour at ~= 2HP.
It's BTUs that the box keeps out, and it's BTUs that the refrigeration unit removes over a 24hr period.
There are perhaps alternatives should you not wish to continue with an engine drive.
With some space, (right, I know, there's never enough,) those "massive" cold-plates can be pushed by a relatively small footprint commercial type 120AC unit of, say ~1/4>1/2HP, that's ~/= to 185>375 watts.
Over the long term, the 12V units are "Plug and Play, then Throwaway".
Well set-up/operated engine units, and/or a 120 unit can be "kept going" by parts that are obtainable the world over, and some resourceful use of basic flaring and soldering skills.
I suppose that like most things on a boat there's always an element of philosophy that shapes our decisions, but I wander.

[bstreep]

Not the same, but we replaced our Grunnert Passagemaker with 2 Seafrost units. Couldn't be much happier.

[wsmurdoch]

A little bit of a tale here. I have a dockside 120V R-12 system. It went flat. The tech said $$$. --- just replace the whole thing. Crying in my beer among dock friends, I was offered cans of R-12 from the shelves in their garages bought long ago. I found the leak --- bad rubber under a service port. Filter/dryer, vacuum. recharge, and all is good years later. I used about an ounce from the can, and I put the rest of the R-12 in a lecture bottle for long term storage not trusting a pierced can.

You get by with a little help from your friends

[Turtle Blues]

Suggest quick look at RParts.com for alternatives. Believe you can find same footprint in a Sanden compressor.

[Bermuda Forte]

I was looking at this one since it has easy access charging ports as compared to what I had.

[Bermuda Forte]

Originally Posted by Bowdrie

I might think twice, perhaps thrice, before I chucked out all of the old system.

IIRC Grunert was not in business when your boat was built in '63, but that is of little concern.

The checking-out tests that Richard posted are valid, but those automotive based compressors are easy and not that expensive to just get a new one.

Any of the 12V pre-packaged units are ~1/6th HP, your compressor, (depending upon several parameters,) will have ~1.5>3HP, 2HP at conservative operation for freezer application.

Most, (if not all,) of the rest of the system is probably "off the shelf" stuff that is still obtainable, (Lots of engine drive systems were built with "Sendure" oil coolers as condenser usage,) and receivers/filter-driers/valves, are commonplace.

The more-or-less typical 12V unit that's running well in a properly insulated box will have a duty cycle over a 24 hr. period of ~12 hrs., so ~50%.

The 12V unit has ~1/6HP and runs for ~12 hours a day.

With a good box and properly sized cold plates the engine drive unit will do with its 2HP. in ~1 hour per day.

You'll notice that the end result is ~more/less the same.

The 1/6HP 12V unit ran for 12 hours=2HP.

The engine unit ran for 1 hour at ~= 2HP.

It's BTUs that the box keeps out, and it's BTUs that the refrigeration unit removes over a 24hr period.

There are perhaps alternatives should you not wish to continue with an engine drive.

With some space, (right, I know, there's never enough,) those "massive" cold-plates can be pushed by a relatively small footprint commercial type 120AC unit of, say ~1/4>1/2HP, that's ~/= to 185>375 watts.

Over the long term, the 12V units are "Plug and Play, then Throwaway".

Well set-up/operated engine units, and/or a 120 unit can be "kept going" by parts that are obtainable the world over, and some resourceful use of basic flaring and soldering skills.

I suppose that like most things on a boat there's always an element of philosophy that shapes our decisions, but I wander.

Thanks for the detailed reply. I’m working my way through the options now that I pulled out all the old gear and I’m cleaning up the engine compartment where it lives.

[Bermuda Forte]

Originally Posted by Coolerking

Sanden 505 , Google that and see what you find.
Make sure you pay attention to the fittings and belts you have on your hoses and select accordingly.
If you switch to 134a, you will need to flush the lines and the plates to remove the oil.
You could also use a direct r12 replacement.
Like hot Shot 2, 417c.
How is the rest of the system?
Do you see the Filter drier, txv's, receiver panel and sight glass?

Here’s pics of what I have, now that it’s mostly on the bench. Any and all advice welcome.

[Bowdrie]

Jeepers, those pics sure brought back some memories.
Yes, that was a typical system from the day.
I'd forgotten that Grunert used a "home brew" condenser. It consists of a coil of tubing that the refrigerant flows thru that's surrounded by a section of PVC pipe that's capped in which the water flows thru.
Those expansion valves, (TXVs,) are still made by Sporlan, and are most likely still good.
The filter and sight-glass are also Sporlan parts, and the receiver is a Standard Refrigeration unit, (not sure if that particular unit is still in production,) but similar units are easy to come by.
The "back seating" shut-off valves are still made, and not hard to get, yours might be still in good shape, they are a "packed" valve and the packing might be OK, "R Parts" has them, but any decent refrigeration supply will have them, they allow you to isolate a part of the system.
The one on the left in the pic, together with the one on the receiver allow you to isolate the filter/sight glass for changing the filter.
That part of the system could use a little better, more user-friendly arrangement, (where a "square drive" service wrench is not required for filter changes, more on that in a later post).
That other part, (with the hoses attached,) is simply a plate that "anchors" the hoses in to which Grunert attached a suction-line filter-drier, (probably also made by Sporlan).
Your new compressor is a good one, the 505s are a very good choice for an engine drive system.
I wish you were closer, I could give you some "hands on" help and you'd have an up-an-running system in short order.
After all these years the part I would be most suspect about is the condenser, (decades of salt water flow can erode the tubing,) that, along with perhaps some corrosion would be good cause for replacement, (I'll see what could work and post it).
For sure you will need new hoses, I don't have any "numbers" offhand, but it shouldn't be a big deal.
Anyway, it looks like you're off to a good start.
PS: The additional expansion valves were for a 12V unit in addition to the engine drive?
If so, what happened?
PPS: What are the dimensions of the eutectic plates, (just curious,) also the little gizmo with the wires is a high-pressure cut-out for the compressor clutch, that set-up might be a candidate for an up-grade to a "High-Low" control.

[Bermuda Forte]

Originally Posted by Bowdrie

Jeepers, those pics sure brought back some memories.
Yes, that was a typical system from the day.
I'd forgotten that Grunert used a "home brew" condenser. It consists of a coil of tubing that the refrigerant flows thru that's surrounded by a section of PVC pipe that's capped in which the water flows thru.
Those expansion valves, (TXVs,) are still made by Sporlan, and are most likely still good.
The filter and sight-glass are also Sporlan parts, and the receiver is a Standard Refrigeration unit, (not sure if that particular unit is still in production,) but similar units are easy to come by.
The "back seating" shut-off valves are still made, and not hard to get, yours might be still in good shape, they are a "packed" valve and the packing might be OK, "R Parts" has them, but any decent refrigeration supply will have them, they allow you to isolate a part of the system.
The one on the left in the pic, together with the one on the receiver allow you to isolate the filter/sight glass for changing the filter.
That part of the system could use a little better, more user-friendly arrangement, (where a "square drive" service wrench is not required for filter changes, more on that in a later post).
That other part, (with the hoses attached,) is simply a plate that "anchors" the hoses in to which Grunert attached a suction-line filter-drier, (probably also made by Sporlan).
Your new compressor is a good one, the 505s are a very good choice for an engine drive system.
I wish you were closer, I could give you some "hands on" help and you'd have an up-an-running system in short order.
After all these years the part I would be most suspect about is the condenser, (decades of salt water flow can erode the tubing,) that, along with perhaps some corrosion would be good cause for replacement, (I'll see what could work and post it).
For sure you will need new hoses, I don't have any "numbers" offhand, but it shouldn't be a big deal.
Anyway, it looks like you're off to a good start.
PS: The additional expansion valves were for a 12V unit in addition to the engine drive?
If so, what happened?
PPS: What are the dimensions of the eutectic plates, (just curious,) also the little gizmo with the wires is a high-pressure cut-out for the compressor clutch, that set-up might be a candidate for an up-grade to a "High-Low" control.

As to PS… yes, there was originally a 2nd system with a huge 12 volt compressor and a keel cooler. I was convinced to abandon it. In hindsight, ‘not sure that was the right thing to do.

And PPS … they are good size plates but I don’t have dimensions handy. There is a separate set of unused tubes. I have often wondered if both sets of tubes traverse all of the plates. It seems that with just the engine driven system the smaller plate in the small freezer side of the box always got very cold, and would easily freeze solid, while not so in the big side of the box. Nothing ever froze in there except on rare occasions.

Can the two sets of tubes be joined together? Would there be any value to doing that?