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conversion

blaster_works on Fri January 25, 2008 1:29 PM User is offline

Year: 1992
Make: toyota
Model: 4runner
Engine Size: 3
Refrigerant Type: r12
Country of Origin: United States

I have never worked with ac systems before but thougfht i would give it a go.

so i have a 1992 toyota 4runner that the ac has slowly stopped or almost stopped working and i want to convert it to 134a. i have bought a good vacuum pump "20 micron" i have bought an inexpensive manifold with guages, conversion kit, i am going to purchase a new drier.

i am planning on removing the compressor and draining all of the oil out of it. flushing all the lines , evaporator, everthing but the valves. as far as what to flush with. i was going to use lacor thinner or crc brakecleen and thoroly blow it out with compressed air.

Now here is what i havent decided yet which oil should i use . toyota recoments there pag oil but i have read its better to convert to the ester oil????? toyota doesnt even recomend flushing the old oil. they say just add the pag oil and call it good. then they go on to say paint the sight glass black because its going to discolor anyway...

myself i think a semicleaned system "i am not putting cleaner in the pump but may fill and drain with the new oil style" with the ester oil would be the right choice.

then half the oil in the pump half inthe dryier , reassembe, evacuatefor an hour or so test for leakes and charge.....



the only other thing that seames weird is the gauger set i bought from harbor frieght looks like a dual manifold for r12 and 134 so i will have to plug the extra ports , kinda wierd...

GM Tech on Fri January 25, 2008 1:53 PM User is offline

The reason your a/c has quit is due to a slow leak--the easiest way to fix this system is to find the leak---look for oily residue-anywhere in or on your system-- and repair as necessary and then evacuate and re-install R-12 which is still readily available and easily obtainable- just that local shops don't wish to deal with it anymore. You can get your certification online and then buy the R-12 online. I don't ever convert systems- the system was designed for R-12 and it is perfectly legal to keep it R-12. The only reason you are wanting to convert it is to use the less expensive R-134a- but you will soon find out it is actually more expensive to convert the system over (if you do it right) then to repair and use the OEM designed refrigerant R-12.....besides if you don't fix your leak- those cans of R-134a will soon drain your wallet anyway......

-------------------------
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......

Cussboy on Sat January 26, 2008 12:04 PM User is offline

Quote
Originally posted by: GM Tech
The reason your a/c has quit is due to a slow leak--the easiest way to fix this system is to find the leak---look for oily residue-anywhere in or on your system-- and repair as necessary and then evacuate and re-install R-12 which is still readily available and easily obtainable- just that local shops don't wish to deal with it anymore. You can get your certification online and then buy the R-12 online. I don't ever convert systems- the system was designed for R-12 and it is perfectly legal to keep it R-12. The only reason you are wanting to convert it is to use the less expensive R-134a- but you will soon find out it is actually more expensive to convert the system over (if you do it right) then to repair and use the OEM designed refrigerant R-12.....besides if you don't fix your leak- those cans of R-134a will soon drain your wallet anyway......


Well-stated !!

blaster_works on Sun January 27, 2008 10:45 AM User is offline

so are you saying its unusual for a 15 year old toyota to need its first ac charge with out a major leak....... i thought it was normal for systems to leak minute quanities over time.

so where is a good location to get r12 on the internet. i found places to get certified for $15

also how hard is it to find the right adapters to hook my hoses up to the toyota fittings. my hoses say r12 among other things but i havent checked the truck fittings yet.

bohica2xo on Sun January 27, 2008 12:49 PM User is offline

15 years without service or a leak is very good. Normal attrition will usually stop a system before that.

I would replace the dryer, it has done it's job. Have a look at the area tangential to the compressor drive for oil. If you don't find any oil leaks, replace the oil lost in the dryer as per the shop manual, and add a dose of UV dye.

Close it up, pull it down for 15 minutes & close the valves. Stop the vac pump and wait for a half hour. If it is still in vacuum you can finish evacuation & charge.

You should have a sight glass, locate it & clean it before you start charging. The sight glass is a great tool above 80f ambients. If it is cold where you are now, you should charge by weight, and use the sight glass as a reference.

If the fan clutch is 15 years old too, you should replace it as well.

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.

blaster_works on Sun January 27, 2008 7:16 PM User is offline

thank you.
so is the consensus to stay with r12.
if i go the retrofit route i will use ester in case i go back..
thanks again

bohica2xo on Sun January 27, 2008 9:50 PM User is offline

Why would you even consider the retrofit?

According to the toyota TSB for retrofitting that vehicle you will experience a "decrese in system performance"...

A dryer changeout, an ounce of oil, some dye & a fan clutch. A couple of labor hours tops. I would swap the fan clutch while the system was pumping down.

The conversion? Remove the evaporator case from the dash, open it, remove the TXV for a full flush. Flush all of the other components clean & dry. Flush the compressor with clean oil. Six labor hours if you hustle, and you still need a new dryer & fan clutch - for less than optimal performance.

Use an OEM toyo fan clutch by the way. Get a bottle of ND-6 oil while you are at the dealer - .7 ounce is the specified ammount for the dryer change out, but an ounce is a safe bet.

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.

blaster_works on Mon January 28, 2008 10:01 AM User is offline

ok i will stay with r12

so what is the best source of r12.
and typical cost.


clutch fan is fairly new so i will test it but unless it looks bad no reason to change it.

ND6 oil ? i thought it was just mineral oil ? guess that is why i am on this forum.


thanks again...

bohica2xo on Mon January 28, 2008 12:22 PM User is offline

blaster:

ND-6 oil is mineral oil. The dealer has it in 60cc bottles for little jobs like this. If you plan to do more work on R12 systems in the future, you can buy a larger bottle of mineral oil at most auto parts stores. Don't forget to pick up some UV dye as well.

If you have replaced the fan clutch recently, great. Too many people believe the clutch is ok if the engine does not overheat, and we see it here all the time.

R12 prices can cover a wide range, depending on how mis-informed the seller is... If you only need a small quantity you can buy cans from a private seller (online auctions, craigslist, etc.) Or you can buy a 30 pound cylinder from several sources - my local AutoZone keeps them behind the counter. This Place has both 12 ounce cans & 30 lb cylinders for sale at fair prices. Just be careful with online sellers of small cans. Many auction sellers are selling a "replacment" as R12 in the header. Look for "vintage" cans...

I suggest a side tap if you go the can route, simply because it will fit everything.

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.

blaster_works on Mon January 28, 2008 1:04 PM User is offline

Thanks again everyones help.

And thanks to the search function i also see toyota had expansion valve problems and some recalls. so depending on what my guages say i may end up talking with them too.

iceman2555 on Mon January 28, 2008 1:21 PM User is offlineView users profile

Considering the age of this vehicle and since the system is already open...the possibility of future TXV problem.....why not simply replace it now...the labor is not overly extensive.....only extra expense...the valve and your time...
Good luck !!!

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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

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