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Discussion Starter · #1 · (Edited)
Have a small oil cooler leak I need to get resolved on my motorhome (see signature) The AC condenser also incl an integral oil cooler on the lower end. I've confirmed it is engine oil and not AC related. Given the dash AC systems in these large RVs barely cools anything (outside of my knee LOL!) I'm scrapping the AC (cap it off). Then install a stand alone cooler.

The 1st and 2nd pic are of the leak (from left). 3rd pic is of fittings at lower drivers side condenser. 4th is where the lines connect to flex lines then to engine. 5th is where lines continue to engine block. 6th is where the lines connect at engine block. 7th is drier connection (pass. side). 8th is discharge top driver side (from compressor). 9th is of unit in situ thru front hatch.

Have spent the last 3 days trying to get a shop (16 diff shops) to do this and either no response or sorry no can do. And I'm reluctantly going to have to do this myself as much as I do not wish to (time mostly LOL).

I was bale to check and see if the lines could be freed and yes after a shot of PB the lower (2) came free relatively easily. Snugged back up.

1. Stand alone cooler choice...Plate or tube/fin?

2. Anyone know what the fitting sizes are pic #3 or #4 (same)? (wrenches used to check were 7/8 hard line side and 3/4 on condenser side).

3. Cooler recommendation?

4. What fitting/s to cap off the AC?

5. This is a schematic of the AC condenser w/integral oil cooler: RV Condenser-Oil cooler.jpg

6. In pic 6 which line is output vs input? (bottom of pic is going to front of RV)

7. Schematic shows the lower (2) fittings as 3/4-16 UNF male (need fittings to connect stand alone cooler line/s).
 

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I was co-owner and moderator of a P-series chassis Yahoo user group for many years and similar questions came up all the time with those old war horses. I personally owned for several years a '96 P-series Bounder, much like your Southwind. So, I'm going to try to help best I can remember .... it was a long time ago.

Question #1 - your choice
#2 - either 1/2"or 5/8" "YN" fittings. Just ask for caps of same size.
#3 - same as #1
#4 - same as #2
#5 - ????
#6 - can't say for sure ....simply don't remember
#7 - 3/4"-16UNF is typically an hydraulic thread. Any good AC shop or regular hydraulic shop should be able to fix you up with hoses/fittings as needed.

To be honest I'm a little confused as to exactly what it is you want to do here but, as far as doing away with the old AC, be aware that's R-12 refrigerant and can be costly if released into the atmosphere. Use your own discretion as to where and how you dump the system. But once dumped, don't even concern yourself with capping anything off on the AC system, just ignore it. That alone will save you much grief and heartburn.

As for connecting up the oil cooler, be aware that almost every old P-30 (GM) bread truck, delivery truck, and other GM step vans will have come without AC. Use any schematics you can find relative to them (circa 1990-2001 IIRC) or actual old trucks still rolling around or junked to find what you need.

Old GM parts manuals for those P-30 step/delivery vans will be a big help as will places like "Rock Auto". Now "Rock Auto" won't list very many, if any parts for the MH chassis, but they will list for the P-30 step vans. That's your road to glory ....... look for parts for the vans then apply them to your motor home project. The P-series chassis engine and tranny on the MH chassis is the same as on the smaller P-30 step vans in most cases.

Regards, Joe
 

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Discussion Starter · #3 ·
Much appreciated for the response. I was planning on installing a stand alone oil cooler but did not know the size of the existing fittings. I wanted to connect the new cooler using the current lines. I've now bought a new condenser w/integral oil cooler (same as old one). This is what I bought...http://acmeairparts.com/rvacheaterparts.html#!/AC-Condenser-94-99-Workhorse-Chassis-GM-P30/p/58426408/category=16022430

The AC system is actually R-134a and given I bought the same condenser w/oil cooler I'll take it to an AC shop and tell them what I replaced and have them evacuate, fill the AC.

When you say caps of the same size...are you referring to each end?

Pics 3 & 4 are the same size The 3rd pic is at the cooler and the 4th pic is where they connect to flex lines that go around lower cooling shroud.
 

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Much appreciated for the response. I was planning on installing a stand alone oil cooler but did not know the size of the existing fittings. I wanted to connect the new cooler using the current lines. I've now bought a new condenser w/integral oil cooler (same as old one). This is what I bought...http://acmeairparts.com/rvacheaterparts.html#!/AC-Condenser-94-99-Workhorse-Chassis-GM-P30/p/58426408/category=16022430

The AC system is actually R-134a and given I bought the same condenser w/oil cooler I'll take it to an AC shop and tell them what I replaced and have them evacuate, fill the AC.

When you say caps of the same size...are you referring to each end?

Pics 3 & 4 are the same size The 3rd pic is at the cooler and the 4th pic is where they connect to flex lines that go around lower cooling shroud.
I guess I'm still a little confused. If you're planning to abandon the AC system, you wouldn't need to 'cap' anything off. Just strip off as many pieces as posible and move on to plumbing your oil cooler. But if you decide to cap some of the lines ends, they should be a 1/2" or 5/8" "YN" cap. I can't tell for certain the actual size, but I'm thinking from memory way back they were probably 5/8". 'YN' is the name for the type of fittings. Pretty standard in the automotive AC and regular hydraulic industries. Any competent AC man or hydraulic tech can look and tell you for certain. I apologize, but it's just been so long since I looked at any of that stuff up close I just don't remember.

Last word of caution, unless that AC system has been converted, I'm almost certain it's an R-12 system. Surely you know your MH better than I, but in motor homes especially, the chassis were built and awaited orders from various RV manufacturers sometimes for more than a year. It's not uncommon to find a MH sold as a '94 to actually be titled as a '93, etc. Only the VIN can say for sure. Since R-134 didn't really come on to the scene forcefully until about '93, '94, or even '95 and was not actually required till '95/'96, with the title lag on RV's it's sometimes a WAG which they are.

Hope this was some help at least. I'll be happy to try to help as much as possible with anything related to the old P-series chassis. I owned one for many years, traveled many miles in it, and loved all the many conversations I had about them. I still have many contacts relative to them so if I don't have an answer, I can probably get one for you. (y)
 

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Discussion Starter · #6 ·
My original plan was to cap it off given I did not know the fitting size and adapters to fit the stock line connectors. I just ended up pulling the plug on the OEM condenser w/integral unit instead. Will fit without the hassle of figuring out fitting connection sizes. Here's a pic of the RV it's going in and a pic of the old condenser/oil cooler unit still in situ...
 

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Nice lookin ol' coach udidwht. I always liked the front end on the 'Southwind' better than I did the 'Bounder'. But, boy those pics of the engine bay earlier sure did bring back some memories.

Good luck on your upgrade/project. jj
 

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Discussion Starter · #8 · (Edited)
Nice lookin ol' coach udidwht. I always liked the front end on the 'Southwind' better than I did the 'Bounder'. But, boy those pics of the engine bay earlier sure did bring back some memories.

Good luck on your upgrade/project. jj
Thanks, it's amazing how few have even sen this type of condenser w/integral oil cooler. When mentioned most respond with...No...no...they don't mix the AC freon and oil I assure you of that blah...blah...(even after explaining that it is (2) separate units in 1).

Then when I show them pics and schematics they scratch their heads. LOL!
 

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Thanks, it's amazing how few have even sen this type of condenser w/integral oil cooler. When mentioned most respond with...No...no...they don't mix the AC freon and oil I assure you of that blah...blah...(even after explaining that it is (2) separate units in 1).

Then when I show them pics and schematics they scratch their heads. LOL!
You'd think most of them would realize that we've had combo engine cooling (radiator) with tranny coolers built inside the radiator for probably about 50+ years. I think I remember them from about the mid 1970's or so .............. ???
 

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Discussion Starter · #10 · (Edited)
This coach has the trans lines running initially to the passenger side tank of the radiator. Then onto the external trans cooler up front. I had first thought it was the same for the oil but not on this coach. No oil lines on the drivers side of the radiator. They run straight from engine block to the condenser w/oil cooler. I believe it was to help aid in keeping to much heat out of the radiator.

The auxiliary fan only has a small portion (crescent shape) actually blowing over the oil cooler itself (bottom end). Most of the fan is pushing thru the AC condenser.

I received the new condenser/oil cooler today. I'll start pulling it apart on Monday. When GM mounted it they mounted it straight to the frame (metal-metal) and vibration will play hell with those tubes. I'm going to cut-size some rubber sections from bicycle inner tube and mount them where the condenser sits/lays to reduce shock & vibration.
 

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Discussion Starter · #12 ·
Complete with exception of filling the AC...

The new OEM one is slightly different though in (2) aspects...


1. My old one the AC drier bottle attaches on both the front and back side edge of the the condenser. The new one only has (2) holes for the bracket on the front.


2. There are no holes )2) on the passenger side edge of condenser for the coolant overflow bottle bracket.

I'll get a better pic up given it was dark when I took this shot.

Automotive tire Hood Automotive lighting Grille Car
 

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Discussion Starter · #14 ·
This was after cleaning the radiator...(see other for before).

For cleaning the radiator I had to use the elbow grease route. The RV storage has no water access. I used 'ZEP HD Citrus degreaser' and a water bottle (several actually) of distilled water to spray clean. Sprayed the cleaner on and agitated with soft synthetic 2.5in wide paint brush working in the cleaner. Then spray with water to wash away the grime, dirt, silt, dogwood, bug etc...

For future cleaning I'll snake a 'Radiator Genie' up from the back under the shroud to clean out.

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Discussion Starter · #15 ·
Update:

All back together and AC system leak checked (20hrs) and charged. Had to adjust compressor air gap. It was .9mm (spec is .4-.6mm) Running real nice and the dash temp gauge is behaving better.
 
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