gnathv
Full Access Member
Any idea how much freon you initially charged it with?
Not Cool!
- Thread starter catbird7
- Start date
Air flow over the condenser should be fine as I recently installed it as well as a new aluminum rad. I can't answer for the evaporator because I never opened the plastic case surrounding it. Thanks for the info, I'll pull a little more 134 out and see what happens. We certainly have the weather for testing!
gnathv
Full Access Member
do you have a decal telling you freon capacity? The charts I have say an 87 should be 56 oz r-12 plus 10 oz mineral oil.
Normally 80% r-134a would be 44.8 oz. to clean your evaporator coil, pull out your fan and spray coil cleaner and rinse with hose. Make sure your condensate drain is clear of any junk. Is red orafice tube for 134a freon?
Normally 80% r-134a would be 44.8 oz. to clean your evaporator coil, pull out your fan and spray coil cleaner and rinse with hose. Make sure your condensate drain is clear of any junk. Is red orafice tube for 134a freon?
gnathv
Full Access Member
Change that capacity to 52oz with 10oz oil.
41.8 r-134a.
41.8 r-134a.
needlenose
Full Access Member
A simple condenser check is to heat the system up normally and then run water over it. If cabin air suddenly cools drastically, then you have a condenser cooling problem.
If you have an AutoZone near you, I believe they rent refer scales. The scales will take all the guess work out of charging. Then you can focus on actual problem; if you even have one.
If you have an AutoZone near you, I believe they rent refer scales. The scales will take all the guess work out of charging. Then you can focus on actual problem; if you even have one.
The complete engine (including compressor) came from my previous truck which was an 89 (if that makes a difference)??? I still have the complete 87 engine and the compressor does look different however the hose connections are the same. I do not have a decal showing the R-12 capacity. Regarding the orifice tubes,,,, actually bought both "red" & "blue" orifice tubes and used the "red" simply because that's the color of the old one I removed from the truck. Still have a new "blue" one. I'll remove that blower motor and check for debris when I get the truck back. Right now it's getting a new windshield (that's another story)..........
gnathv
Full Access Member
that will also mask a system restriction.
gnathv
Full Access Member
86-90 are the same capacity. If you are over filled with oil that will restrict flow and decrease freon capacity.
I removed the hose from the high side and sprayed in about half a can of carb cleaner toward the condenser. Then removed the hose from the lowside plus removed the orifice tube and sprayed the other half can toward the evaporator. Then applied compressed air to the high side condenser line (rag over the low side condenser line) which produced a bunch of oily spray. Did the same thing toward the evaporator. Then blew it out with nitrogen and installed new red orifice tube and reassemble lines. Then hooked up vac and vacuumed the entire system, and loaded the r134.
79jasper
Chickenhawk
I don't know much, but sounds to me like a restriction.
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DaytonaBill
Full Access Member
Ganth is right on his posts...
You are overcharged... Only because you have too much oil in it, PAG 46 is the stuff used by our compressors and after checking for restrictions, charge by weight, 41.6 OZ and be sure you purge charging lines after attaching a new can... or you are adding air and moisture to the system...
Double end cap PAG oil is the best to get, that oil resists moisture, or is not as hydroscopic as regular PAG. I get mine from Carquest and it is the premium PAG made by Supercool...
Ok then, about the gauge readings, it reads high on the low side and way too high on the high side... Overcharged by the low side readout and restriction by the high side readout. The high side should be at the pressure as specified by the ambient temp gas chart. 400 pounds would be correct if the outside air was 183 degrees, but it's not... So, restriction... Btw, your blow out safety valve will blow if it gets much higher than that...
Somewhere between the compressor and the orifice tube, you have a restriction and there is only supposed to be 10 oz PAG 46 oil total in the system. 4 oz in the compressor, 4 oz in the accumulator, one oz in condenser and one oz in evaporator...
The high side pressure would correspond to ambient temps of 183 degree outside air... Not possible, that means you have a restriction and from my past shadetree experiences, I could almost bet there is debris in the orifice tube area and may have slipped into the evaporator when old orifice tube was pulled out.
If the compressor that was mounted on the old engine was disintegrating, also known as "black death", you will still have the black tarry residue creeping from the high pressure side of the condenser to the orifice tube area and that black tar will be carrying debris along with it. There is currently no amount of flushing that will remove the stuff and since you have a presently good compressor with the newer engine, that debris filled black death residue is creeping towards your good compressor and releasing debris to be caught by the orifice screen.
That is where I suspect you will find the restriction, there is probably a coating of Teflon shreds and metallic paste coating your new orifice tube by now...
If so, complete firewall forward replacement along with new evaporator is called for... If you do this, I would offer the suggestion of adding inline filters before the orifice tube in the liquid line and another in the suction line, just before the compressor for protection...
All of this is just my 2 cents...
Oh and after all of this, a heater hose cutoff valve, fresh air and blend door gasket replacement and insulating the outside of the fan and evaporator box is next if you truly want to experience the "meat locker" effect...
You are overcharged... Only because you have too much oil in it, PAG 46 is the stuff used by our compressors and after checking for restrictions, charge by weight, 41.6 OZ and be sure you purge charging lines after attaching a new can... or you are adding air and moisture to the system...
Double end cap PAG oil is the best to get, that oil resists moisture, or is not as hydroscopic as regular PAG. I get mine from Carquest and it is the premium PAG made by Supercool...
Ok then, about the gauge readings, it reads high on the low side and way too high on the high side... Overcharged by the low side readout and restriction by the high side readout. The high side should be at the pressure as specified by the ambient temp gas chart. 400 pounds would be correct if the outside air was 183 degrees, but it's not... So, restriction... Btw, your blow out safety valve will blow if it gets much higher than that...
Somewhere between the compressor and the orifice tube, you have a restriction and there is only supposed to be 10 oz PAG 46 oil total in the system. 4 oz in the compressor, 4 oz in the accumulator, one oz in condenser and one oz in evaporator...
The high side pressure would correspond to ambient temps of 183 degree outside air... Not possible, that means you have a restriction and from my past shadetree experiences, I could almost bet there is debris in the orifice tube area and may have slipped into the evaporator when old orifice tube was pulled out.
If the compressor that was mounted on the old engine was disintegrating, also known as "black death", you will still have the black tarry residue creeping from the high pressure side of the condenser to the orifice tube area and that black tar will be carrying debris along with it. There is currently no amount of flushing that will remove the stuff and since you have a presently good compressor with the newer engine, that debris filled black death residue is creeping towards your good compressor and releasing debris to be caught by the orifice screen.
That is where I suspect you will find the restriction, there is probably a coating of Teflon shreds and metallic paste coating your new orifice tube by now...
If so, complete firewall forward replacement along with new evaporator is called for... If you do this, I would offer the suggestion of adding inline filters before the orifice tube in the liquid line and another in the suction line, just before the compressor for protection...
All of this is just my 2 cents...
Oh and after all of this, a heater hose cutoff valve, fresh air and blend door gasket replacement and insulating the outside of the fan and evaporator box is next if you truly want to experience the "meat locker" effect...
Retrofit capacity for an 87 would be 44oz or 2.75 lbs. You want 3.5oz of oil per pound of refrigerant...so put in 10oz.should use ester when retrofitting.pag is OK if you flush everything thing and start over.
Also replace the blue r12 orifice with an orange tube.it has a smaller orifice and works well with r134a
2.0-2.5x ambient temp.look for 250 psi if it's 100f out.
