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Aftermarket AC system using V7 compressor Pages: 12

ActiveEd on Wed July 04, 2012 12:48 AM User is offline

Year: 1987
Make: Toyota
Model: LandCruiser HJ60 Diesel
Engine Size: 3980cc
Refrigerant Type: R-134a
Ambient Temp: 97
Country of Origin: Canada

I've got an '87 Toyota Land Cruiser that I imported from Canada to Arizona last year, and now that it's getting hot I'd really like to have a working AC system. This truck is pretty much just a big station wagon, lots of glass, lots of space to cool. It's got a 2H diesel engine that was never offered in the U.S. so it can be tricky to find parts for. The truck is 24 volts which adds to the trouble. I've spent over 6 months trying to find a factory AC compressor bracket and 24 volt AC control computer and had no luck at all.This is one of the reasons I'd like to build my own system. Even though it's a diesel, the engine only has 100 hp and 170 pounds of torque so I want the system to be as efficient as possible. I already have some of the parts and I just want to make sure my plan is reasonable before I throw any more money at it, so I'd really appreciate any comments or suggestions. Since this post is ridiculously long I'll underline my questions so they stand out.

Compressor and bracket

After reading on this forum for a couple weeks I decided to go with a variable displacement compressor because it seems more efficient and will allow me to eliminate the AC computer. I initially got a Sanden SD7V16 from a VW Jetta but I couldn't find a v-groove pulley for it. So I read the forum a bit more, gave up on the SD7V16, and instead got a GM Harrison V7 from a 2.2L S-10 pickup. Chose the S-10 model thinking it would be easier to make a bracket for that style vs the V7 from a different car. I put a v-groove pulley from a V5 compressor on it with no trouble. I have a 5 amp, 28 to 14 voltage converter (TI TPS5450) to power the clutch from my 24 volt system. Let me know if that clutch needs more than 5 amps.

The truck idles at 650 RPM and with the pulleys I have the compressor will be spinning at 1.625 times the crankshaft speed, so at idle the compressor will be at 1056 RPM. A factory AC system would idle-up the engine to 950 but I'm not going to include the idle-up in my design. I have a hand throttle I can use to boost the RPM at idle if necessary. Driving around, the RPM is usually between 2000 and 2500, so the compressor will be at 3250 – 4062 RPM. (1) Will the compressor be turning fast enough to operate efficiently with this pulley ratio?

The V7 compressor was originally used in an orifice tube system. I read that the quantity of oil in a TXV system will be less than that in an orifice tube system. GM recommends 9 oz oil for this compressor in a system with 28 oz R-134a. (2) Should I add 9 oz of PAG 150 oil to the compressor, or should I use less because it's now in a TXV system? Does the quantity of oil vary as a percentage of the refrigerant charge?

Since the charge quantity is critical to the successful operation of the control valve in the variable displacement compressor, but there is no support for aftermarket applications, and from what I understand gauges don't help much when charging a variable compressor system, (3) how should I determine system charge? In the U.S. spec Land Cruiser, the R-12 charge was 1.4 - 1.7 lb. Some people recommend 20 oz. for 134a retrofits on this vehicle.

As mentioned above, the TXV I have is for R-12. The V-7 compressor control valve is for R-134a. I'm not sure what color / temperature control valve is in the compressor I have but I assume the control valve is going to operate at a different pressure than the R-12 TXV I have. Since I live in Arizona and the humidity is typically under 20%, I'm not real worried about freezing up the evaporator. (4) Will the system perform better if I swap the V7 control valve to the 37.5 PSI control valve? If not, what control valve will work best with the TXV I have?

Making a bracket to mount this compressor is tricky. The front mounting ears seem to be rotated about 1.5 degrees from vertical, and the rear mounting holes seem to be rotated about 3.5 degrees. I'm having trouble getting the compressor mounted so that the control valve is pointing straight down, it's off by a degree or so. I've measured the front mounting ears at 110mm between bolt centers. The rear mount holes seem to be spaced in no logical way. (5) Anyone have a source for a generic steel bracket for the V7 compressor, or at least a link to a diagram of the mounting holes? This is where I'm at so far: I drew it up in Sketchup, then cut it out of 6 x 6 x 3/16" square tubing, which is turning out to be not as square as I hoped. Pictures of the rough bracket are below. Any advice on bracketry would be great.

The factory AC system uses an idler pulley to tension the belt. (6) If I can tension the belt by adjusting the bracket, is there any reason to use an idler pulley? I don't have one on my bracket yet but can add one easily.


I've been looking for a parallel flow condenser around 16" x 27" with the inlet on one side and the outlet on the other side because the compressor mounts on the opposite side of the car from the evaporator. The only one I've found says it's a 3-pass condenser. Most of the parallel flow condensers that have the inlet and outlet on the same side say they are either 4 or 5 pass condensers. (7) Does it matter if the condenser is 3 pass or 4 pass?

Some of the condensers I've seen are described as parallel flow, then later in the specs they say they are 6mm parallel flow. I thought 6mm was not as good as a true parallel flow. They have the chambers along the full length of both ends like a parallel flow condenser has. (8) Is there a way to tell by looking at the condenser whether it is a 6mm or a parallel flow?

Evaporator and TXV

I have an evaporator from a U.S. spec truck. It's been cleaned and flushed by a local AC shop. I'm putting new foam seals in it and will try to insulate it as best I can. I took out the TXV and cleaned the contact surface of the bulb and the evaporator and put some thermal paste on them and on the copper strap before reassembling. According to the part numbers I have, it's a 1 ton TXV meant for R-12. The orifice is 0.10". (9) When used with R-134a, will this R-12 TXV give an evaporator temperature as low as a TXV designed for R-134a? If not, which TXV should I use? I read that a TXV for R-134a should be a bit smaller, something like 3/4 ton, and will have a different superheat, though I'm not totally sure how this will affect the system. I was tempted to turn the adjustment in the TXV a quarter turn counterclockwise but did not do it.

Hoses and fittings

I'll need to get hoses made. (10) Is there any advantage / disadvantage to using reduced barrier hose vs the regular barrier hose? I think the smaller diameter of the reduced hose will be easier to route.

The V7 compressor I have has a block fitting, and I got a block for it out of a Firebird. It has the same raised step as the compressor and it seems to bolt up okay, but I'm not 100% sure it's the right block. (11) What does the block fitting look like that fits the back of the V7 compressor? What o-rings or seals does it use? I'm planning to cut the aluminum tubing that comes off the block fitting a couple inches from the block so that I can use the bends in it, and then get standard o-ring fittings welded to it.

The factory Toyota evaporator fittings might be metric. A guy at a shop here said they were, but a guy at another shop said they weren't. I think they might be a standard #5 and a #8 but I don't know for sure. (12) What size fittings do I need for my evaporator?

I read somewhere that it's possible to "trick" a variable displacement compressor into running at a lower pressure by using a larger suction hose but it doesn't totally make sense to me, since it will need to get stepped down to fit the compressor block anyway. (13) What size suction hose should I use, standard or oversize?

(14) Where should I put the service ports? I was thinking of putting them both near the receiver-drier unless there is a better place.

Pressure switches

(15) Which receiver-drier should I use? I read to use the largest one possible, and the OEM receiver-drier is pretty big, almost 12" tall. I'd like to use one with a trinary switch built in so it will be easy to wire an electric fan later. (16) If my receiver-drier has a trinary switch, do I need any other pressure switches in the system? Do the switches have different cutoff pressures, or are all R-134a switches going to cut out at the same pressure? I assume that I don't need a thermistor in the evaporator because of the compressor I'm using.

So that's where I'm at. Please let me know if I'm overlooking anything, or doing something completely stupid. I've never done any A/C work before and only just started reading up on it a couple months ago so have a lot to learn.

Edited: Wed July 04, 2012 at 12:50 AM by ActiveEd

GM Tech on Wed July 04, 2012 3:26 AM User is offline

Control valve position down is no big deal-- Heck all 3.1L engines run with it at 8 o'clock position (1994 era) - and it is not for the control valve but for internal lubrication and the oil sump in the cranckcase....I put a V-5 on Dad's combine (my own hang on air)- and just adjusted the charge amount to the best cooling and pressures..

Vee-belts will loosen over time- a tensioner would be good- otherwise the flopping belt-- I used aspring loaded tensioner on the combine application..

All GM block fittings on 134a compressor applications through the h-6, v-5, v-7, - r-4 series are the same- they use sealing washers- not o-rings to seal- standard very common...

You only need a low pressure and high pressure cut-out switch ( can be mounted on high side) you don't want to run with no refrigerant, and you don't want high pressure relief valve to activate if cooling fan fails....

The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

ActiveEd on Fri July 06, 2012 1:14 PM User is offline

Thanks for the info. Looks like I'm overthinking this and making it more complicated than it needs to be. I'll throw it together and see what happens.

bohica2xo on Sun July 08, 2012 6:44 PM User is offline

Nice job on the bracket. Best to overbuild with diesel engine impulses.

Your TXV will be fine. The compressor will balance things on it's own - I have never seen one hunt with a TXV.

For reference, here is the performance chart for the V7:

So you will know how much power it can absorb, and your cruise RPM looks like it will be enough to get to the 12kw point - or about 40k btu/h Make sure you have enough condensor & airflow to deal with that.

Use a large receiver, the OEM should be fine. The sight glass will help you determine charge levels.

Should be a great system when you are done. Keep us posted.


"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.

ActiveEd on Wed July 11, 2012 3:00 AM User is offline

Thanks for the chart and the comments. I'm a little worried now that I won't have a big enough condenser. The OEM serpentine condenser had 375 square inches of fin area; the biggest parallel flow condenser that fits has 367 square inches of fin area.

What's the advantage of using a large receiver? The one I got looks like an aftermarket item for a Toyota pickup. It's a little smaller than the original Land Cruiser part and it has no sight glass. I would get a different one if recommended.

I've got most of the system installed now, just need to finish the compressor bracket, hook up some wiring, and run some hoses.

bohica2xo on Wed July 11, 2012 10:52 AM User is offline

Your condensor size should be fine. Parallel flow units have better heat transfer.

The larger receiver makes it easier to charge & maintain the system. You can add several ounces to the system once you pass critical charge, and it just stays in the receiver. A larger dessicant capacity just means more system protection.

What sort of dryer fittings are you set up for now? A sight glass can making charging a custom system easier.

Sounds like you are getting close to finishing things up. Keep us posted.


"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.

ActiveEd on Mon July 30, 2012 1:58 PM User is offline

Just wanted to update on my progress. I went down to AMA and got all the hoses and fittings. They were really helpful with showing me where to route the hoses and with figuring out what size fittings to use (a different shop I went to couldn't figure out what size fittings were on the Toyota evaporator). So I have all the hoses installed. I pulled a vacuum on it and it held for 24 hours with no leaks.

I bolted up the compressor to check the belt alignment and it looks great. Double checked it with a laser line and it still looks pretty great. I got an automatic belt tensioner from a Chevy Avalanche (Gates 38159) and installed it as a backside idler. It looks lined up and square with the compressor clutch pulley but when I put the belt on and crank the engine the belt gets thrown. If I take the tensioner off, the belt stays on but is too loose. I'm really not sure what the problem is. Seems like the tensioner must be out of alignment or too tight. Any other ideas as to what would cause the belt to get thrown off?

GM Tech on Mon July 30, 2012 5:11 PM User is offline

typically belt tensioners are not used on vee- belts-- so I'd switch the tensioner pulley to one that has sides (flanges) like on a 94 Caprice pulley..then no chance of belt coming off-- but it is probably due to fact you don't have the tensioner behind the drive pulley (cranckshaft)-- the fans are producing drag which lifts the tensioner and then throws the belt- when engine is started-- all automatic belt tensioners have to be on slack side of belt- directly behind drive pulley to work properly..

The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

mk378 on Mon July 30, 2012 5:23 PM User is offline

I'd agree, never seen a spring tensioner on a vee belt-- they need to be pulled tighter than that. Like the stock one with the jack screw and lock nut arrangement. You could probably even put that on the power side though you may experience more bearing wear.

Another possibility could be to move the compressor back and run everything off of one belt, adjust tension in the usual way by moving the alternator.

Edited: Mon July 30, 2012 at 5:25 PM by mk378

bueller on Mon July 30, 2012 7:19 PM User is offline

Also, when using a tensioner like you are with a v-belt, you're probably going to go through belts like one every two weeks if you're lucky. We had a 60's ford p/u here in the shop using the same system you have and it's chewing through belts in less than a weeks time. We're building him a bracket so the compressor has a slide adjustment.

bohica2xo on Tue July 31, 2012 12:46 AM User is offline

Backside idlers are not common on V belts, and can be a problem. They can work, but it is more common to tension a V belt from the inside.

It appears that the idler is on the slack side of the belt. A spring tension, slack side idler works well on the inside of a V belt - we used spring tension idlers in Corvair fan drives with great success. It does take a lot of travel & a fair bit of force. Deutz Diesel also used a spring tension idler on the inside of the V belt for the cooling fan drive on the F5L912 diesels.

You might consider replacing the idler with a V belt pulley like a Gates 38003 or 38004 Mopar used those on a lot of cars. the 004 is 90mm OD, the 003 is 118mm OD. Either one could be used with a spring arrangement or solid adjustment. Should fit on your spring unit, then re-position for inside the belt tension.

One thing I do see is the size difference in the two grooves on the water pump pulley. If the drive ratio for the front groove is not exactly the same as the back groove in relation to the crankshaft pulley, it will toss belts no matter what you do. Check to be sure the drive locations have the same ratio between crankshaft & water pump.

A rigid backside idler can be made to work, but is very hard on belts.


"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.

GM Tech on Tue July 31, 2012 11:16 AM User is offline

In a pinch- I'd get rid of the tensioner- and get a shorter belt and "roll" it on so it is tight enough. may take a couple of tries- but vee-belts are cheap...

The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

ActiveEd on Tue July 31, 2012 3:07 PM User is offline

Thanks for all the comments and suggestions. It's unanimous that my tensioner setup is no good! However, I adjusted the alignment of the tensioner a tiny bit and now the belt stays on. Well, it stays on at idle and up to 1200 RPM or so. I haven't driven it around or tested it beyond that.

I'd much rather use a grooved pulley tensioner with a jackscrew on the inside of the belt but I don't have much space to work with. The factory setup uses this style of tensioner but I wasn't able to find one. The aftermarket tensioners all look too big, and there are absolutely no A/C system parts in the junkyards near Phoenix at this time of year. If anyone knows of a low profile tensioner for a 1/2" belt, please let me know. I found a couple for 3/8" belts but no 1/2". The tensioner that's on it now can only use a 60mm pulley because part of the tensioner arm reaches across the outside edge of the pulley, so I can't just swap the flat pulley to a vee pulley.

I read somewhere that a backside idler would be okay, though not ideal, and would wear the belt faster. Apparently it's common on lawn tractors. I had no idea the belt could only last two weeks like bueller said. That's crazy. I was thinking it would at least go for a year or two. After I took the photos I put a Gates Fleetrunner HD belt on it which wasn't cheap but I was hoping it would be more durable. The belt is pretty tight even without the tensioner. I have to loosen the bolts on the compressor bracket and move it a bit to get the belt on.

To address the other comments: the tensioner is on the slack side of the belt, although it isn't right next to the crankshaft pulley. The belt goes around the crankshaft pulley, then goes about 45° around the waterpump pulley before it gets to the tensioner. The belt turns clockwise when looking at it from the front. This compressor is supposed to turn clockwise, right? There is a size difference in the pulleys on the waterpump and also on the crankshaft but the ratios are the same. The idea of running the A/C and the alternator off one belt is interesting. On this car I think the drive ratio would be wrong for the compressor, but it's something to think about.

I'm going to try it as it is for a while. If it eats belts then I'll swap it out for an inside idler with a vee pulley if I can find one that will fit. I'll update after I get it charged to let you know how it works.

bohica2xo on Thu August 02, 2012 1:23 AM User is offline

I just happened to snap a picture of a good backside idler on a customer's machine today. Machine is a Warner & Swasey lathe that was made in the 1940's and sees daily use. The idler is a backside roller with a big spring loading it. He says the belts last for years, even with less than a full set on the machine:

Now, as far as the compressor belt on the OP's truck - I would use one of the Gates part numbers I already posted & fab up a bracket similar to the one pictured below. That is off of a Ford, and is s simple swing bracket with a pivot bolt & a lock bolt. The square hole fits a 1/2"drive. Simple:

For more ideas, look at the Mopar stuff with V belts in the junkyard. Mopar engineers liked lots of belts & idlers. No real need for a jack screw, just a simple swing & lock will hold up just fine.


"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.

ActiveEd on Fri August 03, 2012 3:21 PM User is offline

I charged the system with a couple 12 oz cans last night. Not sure I did it right, since I've never done it before. But here's what I did. I added 8oz PAG 150 oil, spun the compressor a couple times, then pulled a vacuum for about 8 hours at 100°F ambient. Charged the first can in as liquid through the high side. My scale showed 11 oz left the can. Charged the second can through the low side with the compressor on, 4 oz at first to bring the charge up to 15 oz, then 0.5 to 1.0 oz at a time after that until vent temps rose slightly. Scale showed 8.5 oz left the second can; total 134a out of the cans (and hopefully into the system) was 19.5 oz.

I drove it around a bit this morning, ambient temp was 95°F. With the fan on high and the system on recirculate, the lowest temp I saw at the center vent was 33.2°F. With the fan on fresh air, the lowest temp I saw was 46°F. At high idle (950 RPM) the vent temp on recirc will rise up to high 40s, low 50s. After I drove it for about 10 miles I checked the pressures with all the windows down, the fan on high, recirculate:

Ambient temp: 102°F
RPM: 1000 (compressor RPM = 1625)
Center vent: 53°F
Low side: 35 psi
High side: 330 psi

Last night after I finished charging the pressures were:

Ambient temp: 92°F
Humidity: 34%
RPM: 1000 (compressor RPM = 1625)
Center Vent: 45.5°F
Low side: 30 psi
High side: 125 psi

So I guess I'm wondering if that makes any sense. I'm satisfied with the vent temps but want to make sure I haven't done anything that will damage the compressor. Basically worried that I lost a couple oz of refrigerant to the manifold hoses, so the system may be undercharged.

Why would the high side pressure have gotten so much higher? Does this look okay, or should I vacuum it out and start over?

bohica2xo on Fri August 03, 2012 7:45 PM User is offline

How much oil did you put in the compressor sump?


"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 Sat August 04, 2012 7:35 PM User is offlineView users profile

It is essential that this system be fully charged. Failure to complete charge this compressor will result in a reduction of lubricant flow and premature failure of the compressor. I think a better choice for this installation would be one of the Sanden SD7H15 units. This compressor tends to be a bit more forgiving for slightly undercharged systems. An undercharge can result in a reduction of suction pressure at the control valve and this action results the 'de-strokeing' of the compressor. When this happens lubrication migration to critical bearing surfaces is reduced.
Also this compressor should have had a minimum of 3 oz of lubricant added to the case thru the drain plug in the side. Adding lubricant to the suction port may not allow for sufficient lubricant to be introduced into the crank case. Guide Rod bearing failure is often the result.

The installation is great. Good photos. Hope it works well for you.

These images are Guide Rod Bearing failures due to lack of lubricant. The Reed Valve Plate assembly, notice how there are no drains for lubricant to flow into the compressor body.
The Swash/Crankshaft surface damage due to excessive heat/lack of lubricant and Bronze Bushing damage due to this same condition. This photos were taken from the same unit. The technician did not add lubricant to the compressor in the correct manner. The vehicle was out of the shop for one day. True operational time is not known.

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

ActiveEd on Mon August 06, 2012 12:13 PM User is offline

Well I'm glad I didn't just add oil to the suction port, those pictures look really bad. I added all the oil (8 oz) to the compressor sump. I was originally planning to add it to the suction port but I read a post from GM Tech that the V5 and V7 compressors have the factory fill of the full quantity of oil put into the crankcase oil fill plug, so I did that. I drained the old oil out first, from the crankcase and from the fittings at the back of the compressor while turning the pulley. The old oil that came out of this "rebuilt" compressor looks pretty brown. Does it sound like I added the oil properly? Or should I have added some to the drier or the hoses?

I think the quantity of refrigerant should be at a good starting point. The original r12 system spec was 650 - 750g. I read to use 80% of the r12 charge when converting to r134. 80% of 700g is 560g (19.75 oz), and I've weighed in 19.7 oz so far. The sight glass is just slightly foamy.

Also, I noticed that one of my radiator hoses touches the side of the dryer. I haven't run the system again since I posted last but I'm thinking that as the car warms up the radiator hose gets really hot and warms up the refrigerant in the dryer causing at least part of the high side pressure increase that I'm seeing. I'm going to try to insulate this or move the drier to a cooler location.

There is some condensation on the fittings for the suction hose, both at the firewall and at the compressor. Not sure if that's a problem.

I can report back with some measurements later, but first wanted to make sure the compressor is oiled right and that I'm not going to wreck it by running it more.

bohica2xo on Mon August 06, 2012 1:21 PM User is offline

The sump on the compressor is the right place for oil. I asked because that is a common mistake. Glad you have been reading here.

Foam in a sight glass is an indication of an undercharge, or really bad condensor airflow. Spray the condensor with a garden hose & watch the sight glass.

Your high side on the daytime test is a little high. Make sure the fan clutch is working & all the shrouds are in place. You can check airflow issues by duct taping the gauges to the windshield & going for a drive. 45 to 50 mph pressures will tell you if the airflow is a problem.

You might be undercharged, but let's see if we can reduce the high side before you add any more refrigerant.


"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.

ActiveEd on Mon August 06, 2012 7:40 PM User is offline

I drove around for about 15 minutes with the gauges attached. Looks like my fan clutch isn't working at all! While driving at 40 - 50 mph I checked the pressures every few minutes and saw:

24 —— 235
25 —— 230
26 —— 225
26 —— 260
27 —— 245
28 —— 230
30 —— 268
30 —— 270

Temperature outside was around 105, full sun; humidity at 20%. Center vent temp at 40 - 50 mph, fan on high, fresh air, was around 55° at first but settled in at 48 - 52°F. Temp on recirculate mode with fan on seemed to swing between 40 and 42°F, the lowest I saw it drop was 39.4.

Whenever I would stop the car at a red light, the pressures would start to rise. Highest I saw was 375 / 47 before I turned off the compressor. What pressure does the overpressure valve open at?

I assume I lose some refrigerant every time I hook up the gauges; do I need to add more to make up for this, or is it a tiny amount lost?

Edited: Mon August 06, 2012 at 7:41 PM by ActiveEd

bohica2xo on Wed August 08, 2012 1:35 AM User is offline

Looks like the system will cool well with the airflow sorted out. 55f vents on outside air with 105 ambient temps is not bad.

Some toyota fan clutches are bolted together, and the viscous fluid inside can be replaced. Consult the FSM, and the fluid used to be available as a dealer only part.

Obviously a pusher fan added in front of the condensor to help idle airflow may be of some value in AZ. Many vehicles of that type has such fans installed as OEM parts for hot climates - was this an option for your toyo?

You do lose some refrigerant with the multiple gauge connections. When you are charging a custom system with no factory charge weight, you can watch the pressures to see where the refrigerant begins to fill the space in the receiver. With the cabin fan on the lowest speed, you can add small amounts to the system. The receiver is designed to store some liquid, so the high side pressures should not change much as the refrigerant fills the space. When it is full, the pressure will climb quickly with a single ounce. Keep notes on how much you add. Once you know where "too much" is, max charge is a couple of ounces less than that.


"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.

ActiveEd on Thu August 09, 2012 1:09 AM User is offline

Thanks for the info on the fan clutch. I opened it up yesterday and put new fluid in it.

I didn't get a chance to drive with the gauges hooked up, but the vent temps at idle don't seem to be rising as much as they were before I worked on the fan clutch. However, after it was warmed up I had it idling in my garage for about ten minutes and the high pressure switch shut off the compressor.

I'm going to do some more to try to improve airflow at idle. I haven't sealed the edges of the condenser to the radiator yet, so will do that tomorrow. I'm not 100% sure the fan clutch is working as it should be; will be testing it tomorrow. I don't have a phototach, so a roll of newspaper I guess?

Toyota does offer a pusher fan for this vehicle. The fan wasn't available in North America, as it was only for vehicles with the rear A/C option. I can get one, but at that point would rather just swap out the clutch fan for an electric fan from a Ford Contour.

I don't think I can work on finding the max charge until I get this airflow issue worked out, but the method you described makes sense and sounds pretty easy. Thanks for the info.

bohica2xo on Thu August 09, 2012 2:49 AM User is offline

Seal up the gaps for sure.

The rolled up newspaper really does not tell you much. If you tripped the HPCO, then you know you need more air flow.

I would add a pusher fan, may be enough take care of things.

The mechanical fan is hard to beat for airflow. Some newer OEM electric fans like the Mk VIII Lincoln fan are good units, but they draw a lot of power. It would be necessary to upgrade the alternator to support the 50 amps needed to run the fan...

How hard is it to get parts for a gray market rig like that?


"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.

ActiveEd on Sat August 11, 2012 12:53 AM User is offline

As long as I keep moving, everything works fine. It was 108°F this afternoon and the vent temps were 52 - 55 on fresh air, fan on high. On recirculate the temps were 40 - 42. On recirculate with the fan on low, I think there may be a problem: lowest temp I saw at the center vent was 16.5°F. That shouldn't happen, right? As I understand it, the TXV shouldn't let it get that cold AND the RCV in the compressor shouldn't let it get that cold. Not sure what to do about it.

My fan clutch rebuild didn't make much difference. I don't think the fan is engaging at all, so the compressor gets cut after waiting at a stop light for a couple minutes. If I turn it down to low fan, recirc., then it can run for a bit longer but I'd like to get this resolved. I will probably rebuild the fan clutch again with a different fluid and see if that makes any difference.

I'm doing some research on the pusher fan but it looks like Toyota only sold a 12 volt version. Instead of the pusher, I'm leaning more toward an electric fan instead of the clutch fan. I was thinking that an OEM electric fan drawing 50 amps at 12 volts would only draw 25 amps at 24 volts, assuming I could find one with dual fans and that I could rewire them in series. My alternator could probably handle that. One issue might be finding a reasonably priced 24 volt PWM fan controller.

Getting parts for this thing hasn't been too bad. It's basically the same as a U.S. spec FJ60, but with a different engine and 24 volt electrics. Most of the engine parts are available in the U.S., as Toyota used this engine in some of their forklifts. Other parts can be had from a couple of the Toyota dealers who are willing to order non U.S. parts, and plenty of stuff is available used through the various Land Cruiser forums.

bohica2xo on Sat August 11, 2012 8:17 PM User is offline

Yeah, I wondered about that low side drift in previous posts. Looks like there is a problem with that control valve. Is this a junkyard compressor?

The control valve is easy enough to service. Recover the system, remove the snap ring & pull the control valve.

As for rebuilding the fan clutch, there is only one fluid for the clutch assembly. It is a really viscous silicone based goo.

You can probably locate a pair of 12v pushers to put out front & wire in series.

The idea of wiring a pair of 50 amp electric motors in series will not work - it will still draw 50 amps, just at 24v.

There may be another clutch that can be used if you can't buy a replacement. The forklifts probably had solid fan drives...


"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.

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