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Overheating question Pages: 12

Ecomike on Tue June 23, 2009 10:50 AM User is offlineView users profile

Year: 87
Make: Jeep
Model: 4x4 Wagoneer Limited
Engine Size: 4.0 L
Refrigerant Type: R-134a
Ambient Temp: 95
Country of Origin: United States

My AC has been working for about 12 to 18 months with out needing to add refrigerant. I added the apx. 90% R-134a of a factory spec for R-12 when I converted it, and I had no problems last summer. I recently (last 4 weeks) experienced some engine coolant overheating problems. The overheating problem happens much much faster with AC on, in fact the AC running seems to be the main trigger. I am running out of usual suspects to check on in the engine coolant and engine itself. For the purposes of this question, please assume that everything on the engine and engine coolant system is working properly.

I recall over the years hearing that a working auto AC with a low refrigerant charge (just enough refrigerant to seem to be working properly, but low enough to some how increase the heat load on the engine and coolant system) could make a properly working engine coolant system overheat in very hot weather, but I don't recall the details. We are expecting to hit 99-100 F here today. Also the humidity is much lower than normal for the gulf coast (houston, Tx, very dry heat wave here, no rain in 6 weeks, starting to ration water, and burn ban).

Come someone help refresh my memory on this. How significant is this issue? Is it common, rare, can you quantify the magnitude when it happens?

I have gauges and AC experience so I can check the AC pressures at say 90 to 98 F today if I know what to look for.

Thanks!!!!

HVargas on Tue June 23, 2009 12:08 PM User is offlineView users profile

The reason the a/c will make the car overheat more is because of the load it puts on the engine. It takes a lot of power to turn the compressor and that can build up excess heat in the engine. I would start with the basic things. Check your fan clutch, proper mix of coolant, check your upper and lower hoses to ensure they feel about the same temperature. When was the last time you had the cooling system inspected? Does it do it at idle or driving down the road or both?

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iceman2555 on Tue June 23, 2009 12:44 PM User is offlineView users profile

First, it seems the 'assumption' that the engine cooling system is functioning properly is a major fault with the diagnosis of this system.
Insure that the engine cooling system is fully operational. Check the fan clutch for proper operation. If the fan clutch is over 3 yrs of age or has over 50k miles of operation, seriously consider a replacement. Insure that the rad is fully functioning, a simply reverse flush may not be sufficient to remove internal restrictions.
Operation of the AC with a marginal engine cooling system may result in the problem experienced.

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Ecomike on Tue June 23, 2009 12:49 PM User is offlineView users profile

Thanks for reply, it is appreciated, but as I said in my original post this question is not about the engine cooling system. I am an expert in that area, I have 2 duplicate jeeps with basically all the same hardware, and all of it pretty new........... It is NOT the engine cooling system I am asking about. Please ASSUME it is not the engine coolant system or the engine, radiator etc. PLEASE just focus on the AC question I asked.

Assume I am about 20% below the optimal R-134a charge ( not at the optimal spec, in other words assume about a 6-8 oz leak in last 18 months), not low enough to trip the LP switch or cycle the compressor (my compressor does not cycle at Max AC with fan on high or medium, but will eventually cycle with fan on low if ambient is about 80 F).

Question is can that add a significant heat load to the engine in my current conditions (90 to 100 F ambient, RH about 40%, cloudless day). If so can you can quantify the increased heat load in percent terms. Like does it increase say 20, 30, or 50%?

Ecomike on Tue June 23, 2009 12:54 PM User is offlineView users profile

If you insist on challenging my thesis that it is not the engine, or coolant system, please read the following threads before you try to argue that point further.

http://www.naxja.org/forum/showthread.php?t=999540

http://www.naxja.org/forum/showthread.php?t=998371&highlight=coolant+bottle+renix

http://www.naxja.org/forum/showthread.php?t=998698

http://www.naxja.org/forum/showthread.php?t=952147

Chick on Tue June 23, 2009 4:51 PM User is offlineView users profile

without reading the links you posted, I always get kicked off the site when I copy and paste, the reason it overheats faster with the AC on is the compressor is pumping very hot gas into the condenser which is in front of the radiator, that gets sucked off the condenser and thru the radiator and heats the cooling system faster, which is why we always say you need good airflow thru the condenser even on a properly cooling system.. it's like raising the temp in your radiator faster than the air going thru it can remove it ..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

dynamite196 on Tue June 23, 2009 7:16 PM User is offline

I hate to poke holes in your a/c theory but you yourself stated that the vehicle overheats with and without the a/c, although the a/c does expedite the process. To me, that throws the a/c argument out the window. Of course I do believe the a/c isn't helping matters at this point. This makes sense since the a/c puts a larger load on the engine (through the compressor) and creates more heat flow (through the condenser, as mentioned by chick).
I did scan through a few of your posts and you seem to have replaced pretty much every cooling system component imaginable to no avail; BUT, I still believe this is a cooling system problem, specifically the head gaskets. Needless to say, the vehicle has quite a few miles on it and it's entirely possible that the head gaskets are leaking a little at the coolant passages allowing some of the exhaust gasses to seep into your cooling system causing the overheating. My mother's car had a very similar problem. It ran great during the winter and cooler days but during the hot summer days it would start over heating. A lot of times, if the a/c was turned off the car wouldn't overheat (save for the hottest days, I'm talking 100+ here). There wasn't any coolant loss either, everything pointed to the a/c system being faulty. Eventually, the problem got so bad the car would overheat no matter what (we even pulled the thermostat out and it still overheated). At that point the head gaskets were found defective and replaced. Voila, no more overheating problems since with or without the a/c.
A quick check would be opening the coolant reservoir (not the radiator cap!!) while the engine is running and looking for bubbles. If exhaust gasses are finding a way into your cooling system they have to go somewhere. Check when the engine is cold and also at full operating temperature. If that doesn't yield any results, I would have your coolant lab tested for contaminants (exhaust gasses, oils, etc.) to rule out any possibilities.

Chick on Tue June 23, 2009 8:02 PM User is offlineView users profile

You might want to remove the water pump belt and try wiggling the shaft from the blade end, saw many pumps start to go bad this way without any noise or leaking..Just a thought....

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

Ecomike on Tue June 23, 2009 11:57 PM User is offlineView users profile

Water pump is brand new (not rebuilt). Changing the old, old, old water pump had no effect on the current problem. I have tried 3 new fan clutching, serpentine belt is new, all hoses are new, radiator is fairly new, never used anything but 50/50, old silicate based green formula coolant with deionized water, since I replaced the radiator. Engine head and block looked new and clean when I replaced the water pump and thermostat last week, I found no rust, no calcium or magnesium carbonate scale anywhere, looked like a new head and block.

In the past 4 years, it has always run cooler with the AC on than with it off. The reason being that the when the AC compressor clutch engages it also turns on the electric fan (back up to the primary mechanical fluid clutch drive fan). The electric fan is working, but when I turn on the AC now the cooling system is getting hotter, where as in the past it use to always run cooler with the AC on. In other words, the last four years it ran cooler with the AC on, than off, because the electric fan adding more cooling to the engine coolant system than the heat the AC added to the engine load and condenser to radiator load.

So far there is absolutely no sign of a head gasket leak. The Jeep engine guru ( at NAXJA) on my particular engine says he has lost all the coolant on his engine many times, and pegged the gauge at well over 260 F on the freeway, with out warping a head, or cracking a head or block. This is the old, way over build, over designed, solid cast iron head and block, AMC 4.0 L, straight 6 engine, 1987. It has never lost any coolant, and does not bubble or foam. Note that it is a closed system, with a clear plastic bottle that would show air bubbles easily if the head gasket was leaking.

I can run it at idle in the driveway, in park for 60 minutes non stop, at 100 F ambient, with the electric fan bypassed to run all the time, and hold about 175 F leaving the radiator and 205 F leaving the thermostat housing. (those are todays results, at 90 F ambient, a little better with the second new clutch, as the first new clutch was working one minute and then not the next, I got lucky and caught it playing hooky earlier today, working one minute and not the next, brand new clutch!

But at 90 F ambient, driving 25 miles at 50 mph, with AC on max, it got to 220 F at the thermostat housing and 185 F at the radiator outlet (with the new clutch, which I pre tested on the stove with boiling water this time). If I stopped to simulate 5 pm stop and go traffic with AC still on it would have gotten hotter and probably overheated, especially if it had been between 2 to 5 pm at 100 F instead of just 90 F.

I will be checking the AC pressures next. It would be nice to have some idea what the high and low pressures should read on this system (stock, R-12, 1987) with R-134a, at say 90 F and 100 F at about 40% RH, ambient air. I realize it is going to be a range.

Other than an AC problem, I am leaning towards upgrading the radiator to a 2 row, copper/brass rad. While I have gotten away with an el-cheapo radiator for 4 years, specifically a one row, 1.5" row, aluminum radiator with plastic tanks, I don't think I have pushed it this hard in 100 F weather , with a completely properly working O2 sensor, ECU system, and a working AC system set up with R-134a, all at the same time. I have tended to drive my diesel jeep in the summer the last 4 years, and the gasser in cooler weather. In fact I just completed the R-134a conversion in August last year I think.

Chick on Wed June 24, 2009 6:43 AM User is offlineView users profile

Ok, your high side pressure shoulod be around 2.2 to 2.5 times the ambient temp with a stock R12 system.. Since it was operating OK for some time, no refrigerant added, if you find the high side pressure higher than normal, then air flow is the problem. I know this sounds crazy, but I have fixed cars where the electric fan ran backwards drawing heat from the radiator over the condenser.. Never saw it on a jeep, but as long as your grabbing at straws, check that out...hope this helps..

PS since this is a sealed system, have a leak down test done on the radiator and cooling system, as if you do have a head gasket problem, it's obviously very small... The answer is out there, just have to keep looking until you find it..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

HECAT on Wed June 24, 2009 6:44 AM User is offline

Quote
Originally posted by: Ecomike
Other than an AC problem, I am leaning towards upgrading the radiator to a 2 row, copper/brass rad. While I have gotten away with an el-cheapo radiator for 4 years, specifically a one row, 1.5" row, aluminum radiator with plastic tanks, I don't think I have pushed it this hard in 100 F weather , with a completely properly working O2 sensor, ECU system, and a working AC system set up with R-134a, all at the same time.


I read the comments about this "cheap" radiator in the links you provided. Given all the testing and upgrades that you have done; I would agree that replacing the radiator should be the next step


-------------------------


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FLUSHING TECHNICAL PAPER vs2.pdf 

Cussboy on Wed June 24, 2009 9:30 AM User is offline

Quote
Originally posted by: Ecomike The Jeep engine guru ( at NAXJA) on my particular engine says he has lost all the coolant on his engine many times.

I think it's time to find a new Jeep "guru".


Quote
Originally posted by: Ecomike The Jeep engine guru ( at NAXJA) on my particular engine says he has .... pegged the gauge at well over 260 F on the freeway, with out warping a head, or cracking a head or block.


I think it's time to find a new Jeep "guru".






Edited: Wed June 24, 2009 at 9:31 AM by Cussboy

Ecomike on Wed June 24, 2009 10:48 AM User is offlineView users profile

Quote
Originally posted by: Chick
Ok, your high side pressure should be around 2.2 to 2.5 times the ambient temp with a stock R12 system.. Since it was operating OK for some time, no refrigerant added, if you find the high side pressure higher than normal, then air flow is the problem. I know this sounds crazy, but I have fixed cars where the electric fan ran backwards drawing heat from the radiator over the condenser.. Never saw it on a jeep, but as long as your grabbing at straws, check that out...hope this helps..



PS since this is a sealed system, have a leak down test done on the radiator and cooling system, as if you do have a head gasket problem, it's obviously very small... The answer is out there, just have to keep looking until you find it..

Thanks but it is running R-134a now, not R-12, correct me if I am wrong but doesn't R-134a run a little higher pressure on the high side than R-12?

Not sure I follow your e-fan running backwards fix comment. But note that the Jeep E-fan sits behind the radiator and sucks air through the radiator, it does not sit in front of the condenser, and does not push air front to back through the condenser and radiator..

TRB on Wed June 24, 2009 11:30 AM User is offlineView users profile

Have you listed your high and low side pressure readings on a hot/humid day? Both idle and 1500 rpm would be nice. This vehicle uses a long but skinny condenser. The heat load from this condenser with R134a will be on the higher end. I won't convert and use the OEM condneser on this vehicle.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

bohica2xo on Wed June 24, 2009 4:42 PM User is offline

Quote
Originally posted by: Ecomike



In the past 4 years, it has always run cooler with the AC on than with it off. The reason being that the when the AC compressor clutch engages it also turns on the electric fan (back up to the primary mechanical fluid clutch drive fan). The electric fan is working, but when I turn on the AC now the cooling system is getting hotter, where as in the past it use to always run cooler with the AC on. In other words, the last four years it ran cooler with the AC on, than off, because the electric fan adding more cooling to the engine coolant system than the heat the AC added to the engine load and condenser to radiator load.

You just answered your own question right there. The engine has the capacity to put much more heat into the cooling system than the A/C does. It cooled just fne with the A/C on for years. A/C just moves heat around. If any changes you made to the system doubled the btu's pumped into the condensor, you would have see a corresponding improvement in cabin cooling.
.

Quote
Other than an AC problem, I am leaning towards upgrading the radiator to a 2 row, copper/brass rad. While I have gotten away with an el-cheapo radiator for 4 years, specifically a one row, 1.5" row, aluminum radiator with plastic tanks, I don't think I have pushed it this hard in 100 F weather , with a completely properly working O2 sensor, ECU system, and a working AC system set up with R-134a, all at the same time. I have tended to drive my diesel jeep in the summer the last 4 years, and the gasser in cooler weather. In fact I just completed the R-134a conversion in August last year I think.

Ummmm Yeah. No emissions controls, O2 etc. All of that changed, and it is the A/C's "fault"? A 4 year old "el cheapo" radiator? Ok sure.

4.0L jeeps blow head gaskets just like any other engine, and just as frequently as any other iron I-6. They are not mystical, bulletproof or anything else of the sort.

Do the usual checks. Air path through the condensor stack. Combustion gasses in the coolant. Thermostat opening - even if it regulates temp it may not be opening fully.

If you really think it is the A/C, then posat the results of a full load test for us:

Doors open, cabin fan on highest speed. Engine rpm 1500+. Run for 5 minutes to stabilize the system, and record the High side and Low side pressures while still spinning 1500 rpm. Post the pressures, ambient & vent temperature.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Edited: Wed June 24, 2009 at 4:45 PM by bohica2xo

Ecomike on Wed June 24, 2009 5:23 PM User is offlineView users profile

OK I ran the head gasket leak test, blue fluid that turns yellow if the head gasket is leaking. It is a 2 minute aspiration bubbler test. I ran for 15 minutes, cold, then hot, and at idle and at 3000 rpm, never turned blue. There is NO head gasket leak.

With no AC, after 20 minutes of block tests, resealed the coolant system, ran it for another 10 minutes, ambient at 100 F, and it peaked at 189 F at T-Stat housing and 159 F and radiator exit, so the newest, new clutch is helping just a bit, maybe 3- 5 F cooler, but this was in park, not in drive and not in stop and go traffic after a long drive, so I would expect it to have gone to about 200/170 F with no AC based on prior tests.

So now for the AC pressure data.

It was 120 F inside the car, initial conditions, 100 F outside, about 40 % RH (Max- we are on an extreme dry weather no burn alert, no rain in about 7 weeks, hitting 100 year record highs here this week).

With AC fan on medium, system on Max AC, I got 44/290 PSI in the first minute at idle.

Switched to high fan (Max AC), at idle, got 48/295

Let run a few minutes, then got 30/320 peak at about 2000 RPM (apx), still on High fan-Max AC.

Coolant temps rose to 170/215 F (radiator outlet/T-Stat engine outlet), 5 minutes late it was up to 188/222 F at idle.

5 minutes later it was 45/290 AC pressure (PSIG), inside temp of jeep had dropped from about 120 F to about 85 F.

5 minutes later, had 35/275 AC, about 75 F average inside the jeep (Jeep needs window tint!!!!)

It got down to 30/240 AC pressure, at 2000 rpm (apx), and 40/275 AC pressure at idle with coolant at 192/235 F at a near equilibrium point.


Ecomike on Wed June 24, 2009 5:44 PM User is offlineView users profile

Quote
Originally posted by: bohica2xo
Quote

Originally posted by: Ecomike

In the past 4 years, it has always run cooler with the AC on than with it off. The reason being that the when the AC compressor clutch engages it also turns on the electric fan (back up to the primary mechanical fluid clutch drive fan). The electric fan is working, but when I turn on the AC now the cooling system is getting hotter, where as in the past it use to always run cooler with the AC on. In other words, the last four years it ran cooler with the AC on, than off, because the electric fan adding more cooling to the engine coolant system than the heat the AC added to the engine load and condenser to radiator load.


You just answered your own question right there. The engine has the capacity to put much more heat into the cooling system than the A/C does. It cooled just fne with the A/C on for years. A/C just moves heat around. If any changes you made to the system doubled the btu's pumped into the condensor, you would have see a corresponding improvement in cabin cooling.

Quote

Other than an AC problem, I am leaning towards upgrading the radiator to a 2 row, copper/brass rad. While I have gotten away with an el-cheapo radiator for 4 years, specifically a one row, 1.5" row, aluminum radiator with plastic tanks, I don't think I have pushed it this hard in 100 F weather , with a completely properly working O2 sensor, ECU system, and a working AC system set up with R-134a, all at the same time. I have tended to drive my diesel jeep in the summer the last 4 years, and the gasser in cooler weather. In fact I just completed the R-134a conversion in August last year I think.



Ummmm Yeah. No emissions controls, O2 etc. All of that changed, and it is the A/C's "fault"? A 4 year old "el cheapo" radiator? Ok sure.

4.0L jeeps blow head gaskets just like any other engine, and just as frequently as any other iron I-6. They are not mystical, bulletproof or anything else of the sort.

Do the usual checks. Air path through the condensor stack. Combustion gasses in the coolant. Thermostat opening - even if it regulates temp it may not be opening fully.

If you really think it is the A/C, then posat the results of a full load test for us:

Doors open, cabin fan on highest speed. Engine rpm 1500+. Run for 5 minutes to stabilize the system, and record the High side and Low side pressures while still spinning 1500 rpm. Post the pressures, ambient & vent temperature.



B.

I just posted my data, but I will need to rerun the tests using your suggested procedure above. That said I think you miss read a few things and have, are jumping to several incorrect conclusions. I think my test data last night and today, point to several possible fixes, and maybe a problem with the AC. Overfilled perhaps? But let me run your verision of the AC test next. I ran mine as I would run the AC at start up, to see coolant temp effects, and Max AC pressures.

TRB mentioned he did not like the OEM condensor for R-134a retrofits? Why????

Ecomike on Wed June 24, 2009 5:47 PM User is offlineView users profile

bohica2xo,

Do you want it on normal or Max AC during the doors open test?

Ecomike on Wed June 24, 2009 6:03 PM User is offlineView users profile

325 / 38 PSIG,
64 F vent temp, (using a thermocouple tip sensor in the vent)
steady after 5 minutes, with AC fan on high,
AC on Normal,
car doors wide open,
100 F ambient.

and engine coolant reading 233 F / 198 F (IR gauge at T-Stat and radiator return )

bohica2xo on Wed June 24, 2009 9:07 PM User is offline

Mike:

You have airflow issues. The refrigerant loop is working just fine looking at that test data. The low side is staying below 40 psi, the high side reflects poor heat transfer to atmosphere.

Your compressor is in good shape. That test duplicates a hot day leaving the parking lot after a heat soak, or low speed off-road operation. 1500 to 2000 engine rpm with virtually no road speed. It happens for real, so it is a good overall test.

Airflow through the heat exchanger stack can be affected by many things.
Dirt & small insects get logded deep in the dens fins common to newer heat exchangers. A deep cleaning can be necessary, even on vehicles here in the desert. USe a strong surfactant like Simple Green or Zep Orange full strength on a cold condensor or radiator. Let it soak for 5 to 10 minutes, and flush it out. You can inspect the air path with a drop light in the fan shroud after dark. You might be surprised at how bad that can get.

Missing seals, gaps between heat exchangers, add-on transmission coolers bad fan clutches etc. are usually number two on the list of culprits. Mechanical damage (flattened fins) is number three.

Fan clutches can be a real headache, and aftermarket stuff can be real crap - as you have seen. Another poster on here recently took his old clutch and locked it up by drilling a hole in it & bolting it through. If you have your old clutch you could do the same to make a test unit for yourself.

You have eliminated the obvious - head gasket, thermostat etc. So, it is either additional heat load (engine timing / mixture, transmission slipping, etc.) or a problem transfering it to to the atmosphere. Given that the A/C is struggling, it looks like airflow is the place to start.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

iceman2555 on Wed June 24, 2009 9:09 PM User is offlineView users profile

Assume what you wish....this vehicle has an inadequate cooling system. The cooling system lacks the adequately transfer the necessary heat. Adding the extra heat of the A/C operation exacerbates the over heating. It is not the amount of refrigerant in the system, the system is undercharged that much. The extra heat/pressure of 134a operating within a 12 system is definitely a consideration. A proper operating cooling system should be able to accommodate this extra heat.
Changing the radiator from the single core aluminum to a two/three core brass/copper unit would be a start. Or simply have the radiator properly cleaned. Not flushed, but the tank removed and a rod job. The fill/inlet locations make it difficult to actually determine in there are restricted tubes within the rad. These rads rapidly loose cooling efficiency when the tube inlets begin to become restricted.

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Ecomike on Thu June 25, 2009 1:14 AM User is offlineView users profile

TRB (and any others),

Please tell me more about your thoughts on the stock R-12 AC condenser, and a possible upgrade need there for 134a, in this weather. Do I need more area on my AC condenser to get my high side pressures lower, or are these numbers I posted OK. Personally I was concerned to see them any higher than 275 PSIG.

I think we all agree the radiator I have could be working a little better, but the one I have is working like a new one (it is internally clean enough to eat off of so to speak, and like brand new, it currently performs just exactly like the new one (3 months old) in my 89 jeep, which has an AC leak, so I have not had the overheating problem with it YET) , but it is not a 2 row, OEM copper/brass rad, so I am pretty sure I am going to upgrade the radiator back to a 2 row, heavy duty radiator, like it had before (this jeep had a factory OEM class III tow package on it, and tanny cooler in front of the condenser). Some of the off road rock climbing Jeep XJ guys, with towing needs, have gone to HD 3 row radiators.

I bought the el-cheapo radiator 4 years ago, shortly after buying this jeep, when I was still unsure of its over all rebuildability after finding cold spots in the 20 year old OEM radiator, and at the time, it had a working R-12 system, and with new coolant hoses and a new clutch, it did not run hot anymore, but it was still running open loop on the ECU while I debugged and fixed all the engine ECU/sensor problems it had. I am finally at the point where most everything else is working, and back to spec, except now the 1 row cheap radiator on top of the 134a conversion, and return to proper closed loop operation, and finally trying to drive it all day in this bloody hot weather are overcoming the cooling system.

Thanks for all the help here so far!

bohica2xo on Thu June 25, 2009 4:05 AM User is offline

Upgrading the condensor is a fine idea. Best to go straight to the top, and use a Parallel Flow unit. There will be some plumbing work, but it is worth the effort.

Parallel Flow Condensor Selection

Use the largest one that will fit, and couple it well to the radiator.

325 psi on a 100f day as a full load test is ok, but it could be better. Your HPCO should drop the compressor before 400 psi. A better condensor will help with the pressures - and the vent temperatures.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Ecomike on Fri June 26, 2009 11:44 AM User is offlineView users profile

I am going to try sealing the sides between the condenser and radiator first, as they have a pretty open gap as I recall.

Also going to upgrade the radiator next.

I will post up the results.

Ecomike on Mon July 20, 2009 5:49 PM User is offlineView users profile

I have bought a 3 row, brass CSF radiator.

I also bought a #640129PL parallel flow condenser that fits the '97 Jeep Cherokee from ackits.com, so it will also fit my '87 Cherokee (after modifying the fittings). I have them both now, but I have not installed them yet. Looking at the new '97 PF condenser from ACkits.com, it is only 1/2 the thickness of my old 87 condenser. It does have thinner tubes, about 1/2 the OD thickness of my 87 serpentine condenser tubes, and the 97 tubes are more numerous, twice as many per foot as my old one. But the fact that it has 1/2 the thickness (front to rear, 1/2" versus 1") was a surprise, and has me a little concerned. Should I be worried that I bought too small a condenser even though it is built for the same engine and body 97, as my 87? I went this route instead of the universal, as the 97 had a PF listed with the proper dimensions ( same height and length, and mounting arrangement as my 87, but designed for R-134a....).

Did I screw up with this order, or are these new style beasts that much more efficient?

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