Should AC compressor have compression resistance?
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Mountain Pass
Joined: Jan 2008
Posts: 226
Likes: 4
From: Glendale, AZ
Should AC compressor have compression resistance?
New to me '87 E350 chassis RV with a 460. Dash AC not blowing cold, AC compressor running non stop. When I turn the center inside the clutch (not the ring the belt rides on), I feel no compression. Slight resistance to turning, but smooth through several rotations.
I've done several Suzuki and Chevy AC systems, but I have zero experience with Ford systems, so I don't know if this is normal or not. I haven't yet put gauges on it, as I have them loaned out at the moment.
I've done several Suzuki and Chevy AC systems, but I have zero experience with Ford systems, so I don't know if this is normal or not. I haven't yet put gauges on it, as I have them loaned out at the moment.
Cargo Master
Joined: Sep 2012
Posts: 2,112
Likes: 286
From: Eastern TN
When the compressor’s running, is the high side pipe warmer than the low side? If it’s not warmer, it’s not pumping or has nothing to pump. If it’s warmer but the low side pipe isn’t cool/cold, maybe you have a bad expansion valve (seemed to fail frequently in our ‘77 E250 460).
Is it still running R-12 or converted to R-134a?
Sixto
07 E350 5.4 192K miles
Is it still running R-12 or converted to R-134a?
Sixto
07 E350 5.4 192K miles
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Mountain Pass
Joined: Jan 2008
Posts: 226
Likes: 4
From: Glendale, AZ
I'm not asking why does the AC not work. I'm familiar with the theory of operation of AC systems, I'm just not familiar with the compressors used on Fords.
On my Chevys, I can feel the compression when hand turning the shaft. If I didn't feel it, I know that's a dead giveaway of compressor failure.
I'm assuming this last had R12 in it, due to lack of adapters on the high/low fittings. It presumably has a leak somewhere, as there's very little pressure in the system. Regardless, it will get flushed and all new hoses, O-rings, expansion valve and dryer when I go through the system.
I just don't want to replace a potentially good compressor, as they're not cheap, if I don't have to. On the other hand, there's not much point in throwing 50 bucks of refrigerant in it only to have to pull it all back out again if the compressor is shot.
On my Chevys, I can feel the compression when hand turning the shaft. If I didn't feel it, I know that's a dead giveaway of compressor failure.
I'm assuming this last had R12 in it, due to lack of adapters on the high/low fittings. It presumably has a leak somewhere, as there's very little pressure in the system. Regardless, it will get flushed and all new hoses, O-rings, expansion valve and dryer when I go through the system.
I just don't want to replace a potentially good compressor, as they're not cheap, if I don't have to. On the other hand, there's not much point in throwing 50 bucks of refrigerant in it only to have to pull it all back out again if the compressor is shot.
Hotshot
Joined: Jul 2020
Posts: 10,606
Likes: 2,680
From: Near Salt Lake City
You may not have a cycling pressure switch on that MH or it is too full of freon
Some MHs use the older systems with a POA valve or a capillary tube (especially with R12)
Maybe post a few photos of your accumulator / receiver drier. And the AC hoses at the cowl
Some MHs use the older systems with a POA valve or a capillary tube (especially with R12)
Maybe post a few photos of your accumulator / receiver drier. And the AC hoses at the cowl
Thread Starter
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Mountain Pass
Joined: Jan 2008
Posts: 226
Likes: 4
From: Glendale, AZ
Never mind...no point in going in circles here when people aren't going to bother reading the posts anyways.
I'll just order a new compressor and return it if it feels the same.
I'll just order a new compressor and return it if it feels the same.
Hotshot
Joined: Jul 2020
Posts: 10,606
Likes: 2,680
From: Near Salt Lake City
A new compressor will not feel the same for damn sure
They are real tight at first (the reman ones)
The new ones have a ton of compression resistance
Your old one has very little it sounds like
It is a hard Q to answer is why very few replies
When you install a reman one, they want you to rotate the shaft 10 to 15 revolutions to get some oil worked in there and loosen it up a bit
They are real tight at first (the reman ones)
The new ones have a ton of compression resistance
Your old one has very little it sounds like
It is a hard Q to answer is why very few replies
When you install a reman one, they want you to rotate the shaft 10 to 15 revolutions to get some oil worked in there and loosen it up a bit
Hotshot
Joined: Jul 2020
Posts: 10,606
Likes: 2,680
From: Near Salt Lake City
I'm not asking why does the AC not work. I'm familiar with the theory of operation of AC systems, I'm just not familiar with the compressors used on Fords.
On my Chevys, I can feel the compression when hand turning the shaft. If I didn't feel it, I know that's a dead giveaway of compressor failure.
I'm assuming this last had R12 in it, due to lack of adapters on the high/low fittings. It presumably has a leak somewhere, as there's very little pressure in the system. Regardless, it will get flushed and all new hoses, O-rings, expansion valve and dryer when I go through the system.
I just don't want to replace a potentially good compressor, as they're not cheap, if I don't have to. On the other hand, there's not much point in throwing 50 bucks of refrigerant in it only to have to pull it all back out again if the compressor is shot.
On my Chevys, I can feel the compression when hand turning the shaft. If I didn't feel it, I know that's a dead giveaway of compressor failure.
I'm assuming this last had R12 in it, due to lack of adapters on the high/low fittings. It presumably has a leak somewhere, as there's very little pressure in the system. Regardless, it will get flushed and all new hoses, O-rings, expansion valve and dryer when I go through the system.
I just don't want to replace a potentially good compressor, as they're not cheap, if I don't have to. On the other hand, there's not much point in throwing 50 bucks of refrigerant in it only to have to pull it all back out again if the compressor is shot.
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Hotshot
Joined: Jul 2020
Posts: 10,606
Likes: 2,680
From: Near Salt Lake City
Chev, Subaru, Mercedes all manufacturers are the same when it comes to the AC, with differences only in the clutches and cycling strategy IMO
There are variable displacement compressors and the like now days (yours is a basic one)
You will be fine (you have already had a gauge set on it) and a general idea of what to do
There are variable displacement compressors and the like now days (yours is a basic one)
You will be fine (you have already had a gauge set on it) and a general idea of what to do
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Cargo Master
Joined: Sep 2012
Posts: 2,112
Likes: 286
From: Eastern TN
Lots of good information as usual from mech007 but if it didn’t answer your question, report your findings for the future. How does resistance compare old vs new? For reference, how much charge did you recover from the system when it wasn’t cooling?
Sixto
07 E350 5.4 192K miles
Sixto
07 E350 5.4 192K miles
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