Rebuilt Denso AC Compressors
05-27-2016, 09:10 PM
#1
Burning Brakes
Thread Starter
Rebuilt Denso AC Compressors
So I've changed all the o-rings on my ac system except the one on the compressor itself. I converting to 134a.
My plan is to have the system evacuated and vacuumed.
Then I will replace the dryer and compressor with the new units.
Then I will have the system filled.
My question is my compressor comes filled with the correct oil. Other than installing it on the car and taking it to the mechanic to get filled do any parts need to be moved over. The instructions are generic and say you may or may not need to move over the valves.
My plan is to have the system evacuated and vacuumed.
Then I will replace the dryer and compressor with the new units.
Then I will have the system filled.
My question is my compressor comes filled with the correct oil. Other than installing it on the car and taking it to the mechanic to get filled do any parts need to be moved over. The instructions are generic and say you may or may not need to move over the valves.
05-28-2016, 12:31 AM
#2
Burning Brakes
Thread Starter
Well I might have spoken too soon. There are 2 o-rings going to the expansion valve. Evidently the expansion valve is in another impossible to reach location. I have half the mind to just leave it be and risk the rings are ok, but te thoroughness in me just wants to do it right.
I've heard it can be reach being the glove box. But pictures I'm finding behind the glove box don't show the valve anywhere. Is it in something else and if so how and what do I do to get to it?
I've heard it can be reach being the glove box. But pictures I'm finding behind the glove box don't show the valve anywhere. Is it in something else and if so how and what do I do to get to it?
05-28-2016, 02:14 AM
#3
Rainman
Rennlist Member
Rennlist Member
Early car the expansion valve is under the dash on the side of the evaporator fan assembly.
Takes about 10-20 minutes to remove the whole assembly from the car if the system has already been drained.
When you drop the evap assembly you'll see the lines going to/from it near the back.
Late car the TXV is kind of under one of the "grates" on the blower fan area under the hood...some people have been able to just cut open the grate and reach down to it.
Takes about 10-20 minutes to remove the whole assembly from the car if the system has already been drained.
When you drop the evap assembly you'll see the lines going to/from it near the back.
Late car the TXV is kind of under one of the "grates" on the blower fan area under the hood...some people have been able to just cut open the grate and reach down to it.
05-28-2016, 06:50 PM
#5
Proprietoristicly Refined
Rennlist Member
Rennlist Member
So I've changed all the o-rings on my ac system except the one on the compressor itself. I converting to 134a.
My plan is to have the system evacuated and vacuumed.
Then I will replace the dryer and compressor with the new units.
Then I will have the system filled.
My question is my compressor comes filled with the correct oil. Other than installing it on the car and taking it to the mechanic to get filled do any parts need to be moved over. The instructions are generic and say you may or may not need to move over the valves.
My plan is to have the system evacuated and vacuumed.
Then I will replace the dryer and compressor with the new units.
Then I will have the system filled.
My question is my compressor comes filled with the correct oil. Other than installing it on the car and taking it to the mechanic to get filled do any parts need to be moved over. The instructions are generic and say you may or may not need to move over the valves.
https://rennlist.com/forums/924-931-...ce-needed.html
Flush the condenser also.
GL
J_AZ
05-29-2016, 01:25 PM
#6
Burning Brakes
Thread Starter
Read some of the last posts on this thread:
https://rennlist.com/forums/924-931-...ce-needed.html
Flush the condenser also.
GL
J_AZ
https://rennlist.com/forums/924-931-...ce-needed.html
Flush the condenser also.
GL
J_AZ
Couple questions:
You say in your post on the other thread that you do not flush the compressor or the expansion valve. So where do they hook up the lines to flush the system? Do you have to unhook the expansion valve for them to attach a line to to flush it or is there another port?
After the system is flushed when I install the new compressor, I should first drain the oil it came with, attach it to the car along with the new dryer and have the system evacuated and then the proper amount of oil and 134a added. Is this correct?
05-29-2016, 03:45 PM
#7
Proprietoristicly Refined
Rennlist Member
Rennlist Member
You do not flush the entire system (unless you have had a very serious compressor breakdown---AKA--black death.
You should flush the condenser---the radiator like part in front of the radiator.
One line is from the R/D to the condenser-----this is the TOP line on the condenser.
Unhook this upper line at the condenser if you have bought a aerosol can of flush and inject it here.
The condenser lower line goes to the dash unit--the evaporator, blower, and expansion valve------this line is unhooked at the condenser so you can capture the dirty condenser contamination and the aerosol flush. I hook a spare short hose to the fitting going to a mason jar to capture the flushed fluid.
After the condenser is flushed, put in 2 new "O" rings on the condenser fittings---oil the new "O" rings prior to installation.
I drained the oil that was in the Denso compressor into a shallow pan. I turned the clutch a few times to help empty it. The oil was Esther--a yellowish oil that mixes best with any oil remaining in the system.
To all oil:
Griffiths puts about 8 ounces all into the Denso compressor. Hooks up all components and new "O" rings and turns the Denso clutch 10-12 times to prevent oil saturation on the valves. This will push the oil into the R/D and condenser.
I do it the "tedious" way and put about 4 ounces into the rebuilt compressor, 1+ ounce into the new R/D, and about 2+ into condenser--using the exit hose of the R/D (going to the condenser) and a funnel.
Install all parts with new oiled "O" rings and turn the clutch a couple of times.
Evacuate for at least an hour or longer to remove any moisture. Test to see if it holds pressure. If not, you have a leak.
Freon: Use less R134A ----NOT the same amount as R12. Maybe start with 20 ounces total.
GL
John
You should flush the condenser---the radiator like part in front of the radiator.
One line is from the R/D to the condenser-----this is the TOP line on the condenser.
Unhook this upper line at the condenser if you have bought a aerosol can of flush and inject it here.
The condenser lower line goes to the dash unit--the evaporator, blower, and expansion valve------this line is unhooked at the condenser so you can capture the dirty condenser contamination and the aerosol flush. I hook a spare short hose to the fitting going to a mason jar to capture the flushed fluid.
After the condenser is flushed, put in 2 new "O" rings on the condenser fittings---oil the new "O" rings prior to installation.
I drained the oil that was in the Denso compressor into a shallow pan. I turned the clutch a few times to help empty it. The oil was Esther--a yellowish oil that mixes best with any oil remaining in the system.
To all oil:
Griffiths puts about 8 ounces all into the Denso compressor. Hooks up all components and new "O" rings and turns the Denso clutch 10-12 times to prevent oil saturation on the valves. This will push the oil into the R/D and condenser.
I do it the "tedious" way and put about 4 ounces into the rebuilt compressor, 1+ ounce into the new R/D, and about 2+ into condenser--using the exit hose of the R/D (going to the condenser) and a funnel.
Install all parts with new oiled "O" rings and turn the clutch a couple of times.
Evacuate for at least an hour or longer to remove any moisture. Test to see if it holds pressure. If not, you have a leak.
Freon: Use less R134A ----NOT the same amount as R12. Maybe start with 20 ounces total.
GL
John
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05-29-2016, 05:49 PM
#8
Burning Brakes
Thread Starter
You do not flush the entire system (unless you have had a very serious compressor breakdown---AKA--black death.
You should flush the condenser---the radiator like part in front of the radiator.
One line is from the R/D to the condenser-----this is the TOP line on the condenser.
Unhook this upper line at the condenser if you have bought a aerosol can of flush and inject it here.
The condenser lower line goes to the dash unit--the evaporator, blower, and expansion valve------this line is unhooked at the condenser so you can capture the dirty condenser contamination and the aerosol flush. I hook a spare short hose to the fitting going to a mason jar to capture the flushed fluid.
After the condenser is flushed, put in 2 new "O" rings on the condenser fittings---oil the new "O" rings prior to installation.
I drained the oil that was in the Denso compressor into a shallow pan. I turned the clutch a few times to help empty it. The oil was Esther--a yellowish oil that mixes best with any oil remaining in the system.
To all oil:
Griffiths puts about 8 ounces all into the Denso compressor. Hooks up all components and new "O" rings and turns the Denso clutch 10-12 times to prevent oil saturation on the valves. This will push the oil into the R/D and condenser.
I do it the "tedious" way and put about 4 ounces into the rebuilt compressor, 1+ ounce into the new R/D, and about 2+ into condenser--using the exit hose of the R/D (going to the condenser) and a funnel.
Install all parts with new oiled "O" rings and turn the clutch a couple of times.
Evacuate for at least an hour or longer to remove any moisture. Test to see if it holds pressure. If not, you have a leak.
Freon: Use less R134A ----NOT the same amount as R12. Maybe start with 20 ounces total.
GL
John
You should flush the condenser---the radiator like part in front of the radiator.
One line is from the R/D to the condenser-----this is the TOP line on the condenser.
Unhook this upper line at the condenser if you have bought a aerosol can of flush and inject it here.
The condenser lower line goes to the dash unit--the evaporator, blower, and expansion valve------this line is unhooked at the condenser so you can capture the dirty condenser contamination and the aerosol flush. I hook a spare short hose to the fitting going to a mason jar to capture the flushed fluid.
After the condenser is flushed, put in 2 new "O" rings on the condenser fittings---oil the new "O" rings prior to installation.
I drained the oil that was in the Denso compressor into a shallow pan. I turned the clutch a few times to help empty it. The oil was Esther--a yellowish oil that mixes best with any oil remaining in the system.
To all oil:
Griffiths puts about 8 ounces all into the Denso compressor. Hooks up all components and new "O" rings and turns the Denso clutch 10-12 times to prevent oil saturation on the valves. This will push the oil into the R/D and condenser.
I do it the "tedious" way and put about 4 ounces into the rebuilt compressor, 1+ ounce into the new R/D, and about 2+ into condenser--using the exit hose of the R/D (going to the condenser) and a funnel.
Install all parts with new oiled "O" rings and turn the clutch a couple of times.
Evacuate for at least an hour or longer to remove any moisture. Test to see if it holds pressure. If not, you have a leak.
Freon: Use less R134A ----NOT the same amount as R12. Maybe start with 20 ounces total.
GL
John
One last thing I'm not understanding - if you put the oil in the new freshly rebuilt system and then evacuate the system to draw a vacuum on it won't that suck the oil back out?
05-29-2016, 06:27 PM
#9
Addict
Rennlist Member
Rennlist Member
When you vacuum the system you are removing moisture in the lines. A vacuum drops the atmospheric pressure to allow water to boil at room temperature. As the water boils it changes to a vapor state, and this vapor is drawn out by the vacuum pump. Oil will stay in the system.
I also put the oil in the compressor and then rotate after attaching the hoses. I flush by putting flush into the filter/drier high side hose going to the evaporator and blowing the liquid through the evaporator and expansion valve. I put the low side compressor fitting in a bucket to catch the flush and do this till the liquid looks clean.
I also do the same for the condenser.
I also put the oil in the compressor and then rotate after attaching the hoses. I flush by putting flush into the filter/drier high side hose going to the evaporator and blowing the liquid through the evaporator and expansion valve. I put the low side compressor fitting in a bucket to catch the flush and do this till the liquid looks clean.
I also do the same for the condenser.
Last edited by Charlie; 05-29-2016 at 06:51 PM.
05-29-2016, 06:27 PM
#10
Proprietoristicly Refined
Rennlist Member
Rennlist Member
Condenser sounds great-nice and clean.
Vacuum will not remove the oil. It is designed to only remove moisture and air at the ports.
Vacuum for 15 minutes at first----stop----see if it holds vacuum---if OK vacuum for another hour to remove moisture.
You need a medium size vacuum pump. I use a Harbor Frieght:
http://www.harborfreight.com/25-cfm-...ump-98076.html
($$ less normal coupon of 20%)
....or better.
GL
J_AZ
Vacuum will not remove the oil. It is designed to only remove moisture and air at the ports.
Vacuum for 15 minutes at first----stop----see if it holds vacuum---if OK vacuum for another hour to remove moisture.
You need a medium size vacuum pump. I use a Harbor Frieght:
http://www.harborfreight.com/25-cfm-...ump-98076.html
($$ less normal coupon of 20%)
....or better.
GL
J_AZ