RV-2 Shaft Seal

[JimKueneman]

Has anyone successfully installed a new shaft seal? I am struggling the remember the stack up of the multi part seal and have failed to get it to seal. The manual and parts book are useless to see the details to the level I need to see them. I can not find anything on the web that shows the exact orientation of the parts as they go on the shaft. I have a new seal set coming that should be here by Wednesday. I have the original seal that I can take photos of and I could take the new one back out for photos of that too.

Thanks,
Jim

 

[idrivemopar]

Is this not detailed enough?

 

[JimKueneman]

No, there are subtle differences in the parts contained in the bracket "seal". They are not the same on each side of the part and if flipped 180 degrees and installed are completely different (and wrong). Plus the aftermarket seal does not look like the original so that adds one more confusing item if you don't really understand how the seal actually functions. I have found something that more or less shows me what I needed to know. I think I understand how the seal works after looking at these photos.

http://www.hotrod.com/articles/34597-mopar-ac-system-restore-iii/

 

[Darter6]

We were taught to never touch the seal surface with bare fingers as the skin oils/acids will contaminate the seal.Also coat the seal with a liberal amount of A/C oil when installing.Just a thought .

 

[JimKueneman]

We were taught to never touch the seal surface with bare fingers as the skin oils/acids will contaminate the seal.Also coat the seal with a liberal amount of A/C oil when installing.Just a thought .

Agreed but what I had not realized there are TWO sealing surfaces, one is the normal around the shaft but there is a carbon ring that is a thrust washer type seal to seal it against the cover and presses against the bearing race.

 

[RJRENTON]

This is a simple carbon vs ceramic mechanical seal. Usually the carbon (actually a non porus high density graphite material) is the rotary half and is sealed to the shaft with an O ring. The other half of the seal is a super hard ceramic material and is the non rotating part. It is sealed to the housing with an O ring on its OD. The sealing faces of the rotary and stationary parts are lapped to with in 2 helium light bands of flatness. AND SHOULD NOT BE TOUCHED BY HANDS/FINGERS. Apply a few drops of refrigerant oil, compatible with the refrigerant that will be charged....R134A is polyol Ester vs R12 oil's mineral oil base.....to the O rings and seal faces...and CAREFULLY install the parts....they are a very effective seal but VERY FRAGILE...DO NOT FORCE ASSEMBLY.
Bob Renton

 

[dieseldazzle]

Man bob..... you humble me

 

[RJRENTON]

DD,
Thanks for the vote of confidence.....in another lifetime, i ran a 70 man maintenance department in a chemical plant, where i was responsible for all the equipment, including high temperature process chemical evaporators operating under vacuum. Most of the adjatators in the evaporator vessels (5000 - 10000 gallon capacity) operating at 700 degrees F, had two sets of seals on the shafts (5 -6 inches in diameter) which required forced lubricant and cooling systems. The little Chrysler RV2 AC compressor is sort of simple.....compared to what I'm used to seeing.
Thanks again for your comment and interest.
Bob Renton

 

[JimKueneman]

DD,
Thanks for the vote of confidence.....in another lifetime, i ran a 70 man maintenance department in a chemical plant, where i was responsible for all the equipment, including high temperature process chemical evaporators operating under vacuum. Most of the adjatators in the evaporator vessels (5000 - 10000 gallon capacity) operating at 700 degrees F, had two sets of seals on the shafts (5 -6 inches in diameter) which required forced lubricant and cooling systems. The little Chrysler RV2 AC compressor is sort of simple.....compared to what I'm used to seeing.
Thanks again for your comment and interest.
Bob Renton

Here is the seal

http://www.classicindustries.com/product/mopar/b-body-coronet/parts/md646747.html

When I get it I will post photos of the different sides and you can tell me if you think my assembly sequence is correct if you don't mind. The thing in the middle if you flip it over had a raised ring (about 0.50" or so). I say that is what contacts the carbon ring (right bottom) and that is inserted in the right top carrier/shaft seal.

 

[RJRENTON]

Jim,
I think you are correct in your assumption. The parts shown in site's pix grouping really does not show a lot of detail ... just an overall view. I'll try and help you sort things out....it would be helpful to compare the old parts with the new parts. They should be similar but dimensionly the same.
Not sure who provided the original seal...there are several manufacturers.....John Crane, DuraMetallic, Chesterton, plus others. I've used all types and components....carbon vs ceramic, tungsten carbide vs ceramic, tool steel vs niresist, just to name few possibilities...it depends on application...
Bob Renton

 

[JimKueneman]

Jim,
I think you are correct in your assumption. The parts shown in site's pix grouping really does not show a lot of detail ... just an overall view. I'll try and help you sort things out....it would be helpful to compare the old parts with the new parts. They should be similar but dimensionly the same.
Not sure who provided the original seal...there are several manufacturers.....John Crane, DuraMetallic, Chesterton, plus others. I've used all types and components....carbon vs ceramic, tungsten carbide vs ceramic, tool steel vs niresist, just to name few possibilities...it depends on application...
Bob Renton

Thanks, I also have the original seal parts. My stupidity is I did not take good photos during disassembly, I assumed the manual would be clear as to how it all went together. It is not. There are 3 parts with two sides each so that is the number of possible combinations is a factorial....power? (I hated probability classes)

 

[RJRENTON]

Jim,
I think you mean: permutations and combinations, expressed as: P (n,r) = n! ( n-r)! Something about factorial expression is written as, for example: 3! = 3 × 2 × 1.... Anyway..thus endith the lesson.... too many years ago that i studied this......I'll try to help you put Humpty Dumpy back together again. PM if you prefer.
Cheers
Bob Renton

 

[dieseldazzle]

I'd be happy to pull a parts compressor apart for you if it comes to that Jim

 

[JimKueneman]

I'd be happy to pull a parts compressor apart for you if it comes to that Jim

Appreciate the offer. I think I have it figured out. If all the refrigerant leaks out I may take you up on this.

https://www.forbbodiesonly.com/mopa...net-500-project.114333/page-39#post-910641729

 

[RJRENTON]

Jim,
Looking over your pix and the other contributors efforts, it appears that you are well on your way. I concur with the premise of evacuating the system to insure that all moisture is removed. If the system has been open to atmosphere for any length of time, you should consider replacing the dryer....unless of course you are recharging with R134A, thrn its a must.
When charging yhe RV2 compressor i always used the charge port on the cylinder head NOT on the EPR valve port on the suction line. The EPR valve (evaporator pressure regulator valve) maintains a constant evaporator pressure to prevent icing. IF you are changing with R134A refrigerant, this valve is rrmoved AND the system pressures will be radically different. With the old R12 refrigerant, the suction pressure was best at 30-35 psi, with blower on high snd a fan blowing on the condenser.
But, this is just my opinion. If I can help or advise let me know.
Cheers
Bob Renton

 

[JimKueneman]

Jim,
Looking over your pix and the other contributors efforts, it appears that you are well on your way. I concur with the premise of evacuating the system to insure that all moisture is removed. If the system has been open to atmosphere for any length of time, you should consider replacing the dryer....unless of course you are recharging with R134A, thrn its a must.
When charging yhe RV2 compressor i always used the charge port on the cylinder head NOT on the EPR valve port on the suction line. The EPR valve (evaporator pressure regulator valve) maintains a constant evaporator pressure to prevent icing. IF you are changing with R134A refrigerant, this valve is rrmoved AND the system pressures will be radically different. With the old R12 refrigerant, the suction pressure was best at 30-35 psi, with blower on high snd a fan blowing on the condenser.
But, this is just my opinion. If I can help or advise let me know.
Cheers
Bob Renton

Thanks Rob, yes I have a new dryer and yes it is swapped out with 134a oil, fittings, O-rings, and the EPR valve is removed. I have not installed a cycling switch as here in the desert that is rarely a problem and if it does I understand the problem. Thank you for the comment to fill it through the cylinder head, I will do that. I also read to not fill it too fast as you can damage the reed valves if you allow a big blast of refrigerant in its liquid state. Classic Air recommends filling it with about 80% of the R12 label and says bubbles in the sight glass are mandatory for the right pressures (though my replacement drying does not have a sight glass.

If a system can't hold a vacuum overnight is that an indication of a small leak. I have never tried to do that before. The cheap gauges could be leaking, plus the seals are suppose to hold pressure not vacuum so it is not clear if a bit of seepage in the wrong direction is normal. This morning it was back up to atmosphere.

 

[RJRENTON]

Jim,
Looks like you have everything under control. As far as the cycling switch position and setting....this is similar to the GM's CCOT system: Cycling Clutch Orifice Tube cohtrol, where the evaporator's pressure, as it relates to temperature, is controlled by cycling on and off the compressor's clutch....to obtain an AVERAGE pressure (and temperature) to just slightly above the freezing point of the accumulated water..condensate..yet achieve maximum cooling to the passenger compartment. If you could find an ajustable pressure switch that is normally closed snd OPENS on pressure fall, so you could dial in the temperature / pressure you prefer. You may have to retain the expansion valve to prevent evaporator flooding (too much refrigerant). The oem expansion valve has different flow characteristics with R12 and MAY NOT work with R134A. I think a conversation kit would solve this issue.
Let us know how you make out. BTW....i use a thermocouple vacuum gauge that reads down to 500 microns, which is "outer space vacuum". Vacuum should hold for st least 8 hours.....but this is just my opinion.
Cheers,
Bob Renton

 

[JimKueneman]

Jim,
Looks like you have everything under control. As far as the cycling switch position and setting....this is similar to the GM's CCOT system: Cycling Clutch Orifice Tube cohtrol, where the evaporator's pressure, as it relates to temperature, is controlled by cycling on and off the compressor's clutch....to obtain an AVERAGE pressure (and temperature) to just slightly above the freezing point of the accumulated water..condensate..yet achieve maximum cooling to the passenger compartment. If you could find an ajustable pressure switch that is normally closed snd OPENS on pressure fall, so you could dial in the temperature / pressure you prefer. You may have to retain the expansion valve to prevent evaporator flooding (too much refrigerant). The oem expansion valve has different flow characteristics with R12 and MAY NOT work with R134A. I think a conversation kit would solve this issue.
Let us know how you make out. BTW....i use a thermocouple vacuum gauge that reads down to 500 microns, which is "outer space vacuum". Vacuum should hold for st least 8 hours.....but this is just my opinion.
Cheers,
Bob Renton

Do these seals need to be run in to seal completely sometimes?

 

[RJRENTON]

Jim,
It has been my experience that the seal does not need to be run in to seal. It should hold pressure (or vacuum) from the get go. If by chance that either the rotary or stationary element is out of square (even slightly) or if the seal faces are out of parallel, even slightly, seal will leak. Usually a pressure leak will show as refrigerant oil on the magnetic clutch faces, and over time, refrigerant loss. I'm sure that the cost of the seal is significant but the hassle factor is probably a consideration. The system should hold vacuum at least 8 hrs ..... but this is just my opinion. Since the compressor has reed valves be careful when charging not to "slug" the compressor with liquid refrigerant. Remember, air is considered a non-condensable, and will inhibit the condensing of the refrigerant and the systems overall efficiency. Keep us posted....
Cheers
Bob Renton

 

[JimKueneman]

Jim,
It has been my experience that the seal does not need to be run in to seal. It should hold pressure (or vacuum) from the get go. If by chance that either the rotary or stationary element is out of square (even slightly) or if the seal faces are out of parallel, even slightly, seal will leak. Usually a pressure leak will show as refrigerant oil on the magnetic clutch faces, and over time, refrigerant loss. I'm sure that the cost of the seal is significant but the hassle factor is probably a consideration. The system should hold vacuum at least 8 hrs ..... but this is just my opinion. Since the compressor has reed valves be careful when charging not to "slug" the compressor with liquid refrigerant. Remember, air is considered a non-condensable, and will inhibit the condensing of the refrigerant and the systems overall efficiency. Keep us posted....
Cheers
Bob Renton

OK thanks. Since the system hasn't been run in 35 years it's hard to say if anything else has got a small crack or something wrong with it. I think I'm just going to pump it down for three or four more hours and fill it full of Freon in a little bit of dye and see what happens