AC NOT COOLING - 1982 300-SD - Page 3 - PeachParts Mercedes-Benz Forum

nyko46 · #31 06-21-2011, 07:41 PM

Quote:

Originally Posted by leathermang

Yes, that is more in keeping with standard procedure for the R4..
however, you should measure the amount you try to put into the R4 and if it will not take and keep that much... add that amount not put into the compressor back so the total amount in the system is correct.. it will then distribute itself around as it wants to based on the physics of the inner workings..... if that is the case.. compressor not holding the amount you expect to add... then I would put half the extra oil into the evaporator so that is it downstream of the Txvalve and upstream of the compressor. The other half of the ' extra' I would put into the rec-dry if it will fit...

Now we are in the same page.
Question: Since the evaporator lines after the TEX are upside down (facing down) how to add oil into the evaporador?
Is my Four Season #58-228 a R4 compressor?
I know that it have the same construction style than the original Delco from MB 1982 - 300SD and fit properly in the car.

engatwork · #32 06-21-2011, 07:43 PM

The way I do it is that I put the correct amount of oil in a measuring cup and start adding it at the different sections as I am buttoning them up. Typically, I will try to get at least an ounce in the compressor. Add a little oil into the inlet port and turn the center part of the pulley by hand, add a little more oil and turn again. I suspect you can eventually get to the point where it would be pumping out of the discharge side but I don't know what quantity it takes to do this. The main thing is to make sure you have gotten some oil in it and you have turned it by hand alot (20 to 30 turns come to mind). You will spill some if it is overfilled when you go to re-install it. I put the remainder of the oil into the system as I put it together.

In regards to the above post hook it up with the exp valve and hoses and get to the first place where you can hold the end of the hose in the vertical position. This is where you can add oil.

I'm pretty sure that you are not going to get exact amounts in the various areas. The key thing is to get whatever you have measured out into the cup into the system. It will get distributed when the freon starts flowing.

leathermang · #33 06-21-2011, 07:53 PM

Good description Jim...
I was just trying to get his attention after he posted THIS :

"After getting the new compressor drained, I will put 8 oz of PAG 150 in it and that is it. As informed by other guys from this site, oil ONLY in the compressor even with the system completely cleaned and empty."--Nyko46

Which of course was a total misreading of what had been suggested.

nyko46 · #34 06-21-2011, 07:53 PM

Quote:

Originally Posted by engatwork

The way I do it is that I put the correct amount of oil in a measuring cup and start adding it at the different sections as I am buttoning them up. Typically, I will try to get at least an ounce in the compressor. Add a little oil into the inlet port and turn the center part of the pulley by hand, add a little more oil and turn again. I suspect you can eventually get to the point where it would be pumping out of the discharge side but I don't know what quantity it takes to do this. The main thing is to make sure you have gotten some oil in it and you have turned it by hand alot (20 to 30 turns come to mind). You will spill some if it is overfilled when you go to re-install it. I put the remainder of the oil into the system as I put it together.

In regards to the above post hook it up with the exp valve and hoses and get to the first place where you can hold the end of the hose in the vertical position. This is where you can add oil.

I'm pretty sure that you are not going to get exact amounts in the various areas. The key thing is to get whatever you have measured out into the cup into the system. It will get distributed when the freon starts flowing.

Thanks, Jim;
It was very helpful.
I believe if I use a seringe with division in CC with will work to add oil in the evaporator/TXvalve, condenser, receiver, and compressor, don't you think?
My receiver was recently installed and I am planning to use the same one after flush the system. Do think it will work properly?

leathermang · #35 06-21-2011, 07:56 PM

No, you need to replace the receiver...that is standard procedure as a safety device for moisture which may have saturated this one when system is opened up. It is very important as an acid/oil -moisture blocker.

SD Blue · #36 06-21-2011, 08:02 PM

Sorry for the confusion, and the misunderstanding, if you are changing any of the other components you can add the rule of thumb amounts of refrigerant oil anywhere in the system.

However, if you are changing the compressor, you need to add oil (the specified amount listed in this link: R4 compressor A/C system OIL charge Per WIS: 83-520) directly to the suction port of the compressor. This is to prevent a "dry start" of the compressor. Then, the remaining oil can be added anywhere else in the system.

From my understanding, and since there was an oil "overcharge"and a re-opening the system to flush, replacing the receiver/drier sounds like money ahead thinking to me. I haven't seen anything in writing saying it is absolutely mandantory but there are probably folks here, with far more experience, that may have different opinions. I would hate to think that a $25 rec/drier caused a premature failure after all the work you've done so far.

nyko46 · #37 06-21-2011, 08:04 PM

Quote:

Originally Posted by leathermang

No, you need to replace the receiver...that is standard procedure as a safety device for moisture which may have saturated this one when system is opened up. It is very important as an acid/oil -moisture blocker.

After system opened, even new receivers MUST be replaced?

leathermang · #38 06-21-2011, 08:07 PM

That is STANDARD procedure since the part is cheap but IMPORTANT...just as SDBlue just said in his last paragraph.... you are spending a lot of money and time redoing this... and for so little money you would not want it to last only a couple of years instead of the 6-8 it should without any attention...

MUST is a funny word.... it is your car and you do not have to replace it... I am just saying that if you have read as much over the years as I have... I know of NO Professionals which would take a chance on reusing after opening up the system....

AND in that same way.... you need to keep the new one CLOSED until the very last seconds before you install it in the system... to keep moisture from getting to the new one...

nyko46 · #39 06-21-2011, 08:12 PM

Quote:

Originally Posted by SD Blue

Sorry for the confusion, and the misunderstanding, if you are changing any of the other components you can add the rule of thumb amounts of refrigerant oil anywhere in the system.

However, if you are changing the compressor, you need to add oil (the specified amount listed in this link: R4 compressor A/C system OIL charge Per WIS: 83-520) directly to the suction port of the compressor. This is to prevent a "dry start" of the compressor. Then, the remaining oil can be added anywhere else in the system.

From my understanding, and since there was an oil "overcharge"and a re-opening the system to flush, replacing the receiver/drier sounds like money ahead thinking to me. I haven't seen anything in writing saying it is absolutely mandantory but there are probably folks here, with far more experience, that may have different opinions. I would hate to think that a $25 rec/drier caused a premature failure after all the work you've done so far.

I will agree with you about the receiver/drier because in my case, there was an overcharge of oil in the system. This job alredy gave me too much head ache and I do not want this problem again.
One thing I can say, I learned a lot doing this project never done before.
Thanks to everyone.

engatwork · #40 06-21-2011, 08:15 PM

I replace the dryer whenever I have one opened up for more than about an hour.

The spec listed calls for 2.3 ounces in the compressor. The issue is going to be when you turn it up into the position that it is going to be mounted. Go ahead and try to put that amount in there and spin it by hand alot. You will need to pour it in, spin it some, pour some more in and spin some more. Do this till you get the proper amount in there and then install the compressor. Some of that oil will likely spill out and you will need to try to make it up if it is very much. You have to work kinda fast getting those hoses bolted up.

It took me this long to get into this thread because I had to get to this posting to understand what was going on:

Quote:

Now we are in the same page.

LOL

Good job nyko46. You can get your answers here once everyone is on the same page

.

nyko46 · #41 06-21-2011, 08:24 PM

Quote:

Originally Posted by engatwork

I replace the dryer whenever I have one opened up for more than about an hour.

The spec listed calls for 2.3 ounces in the compressor. The issue is going to be when you turn it up into the position that it is going to be mounted. Go ahead and try to put that amount in there and spin it by hand alot. You will need to pour it in, spin it some, pour some more in and spin some more. Do this till you get the proper amount in there and then install the compressor. Some of that oil will likely spill out and you will need to try to make it up if it is very much. You have to work kinda fast getting those hoses bolted up.

It took me this long to get into this thread because I had to get to this posting to understand what was going on:

LOL

Good job nyko46. You can get your answers here once everyone is on the same page

.

Oil spilling from compressor at the time to have the ports mounted was happen to me when I install it for the first time. Since the ports in the hose side are not much flexible it is hard to connect it without any spill.
Unless there are any other way to install it. I work with my car lifted only by jack stands and there are not much room to work to fast.

engatwork · #42 06-21-2011, 08:28 PM

In that case then just do the best you can, estimate what you spill and add it to the measuring cup when you add it throughout the system.

nyko46 · #43 06-21-2011, 08:33 PM

Quote:

Originally Posted by engatwork

In that case then just do the best you can, estimate what you spill and add it to the measuring cup when you add it throughout the system.

This is a great idea.
I will have my new compressor emptied and will add the 2.3oz of oil and try to install it using a lot care to spill the minimun possible.
Any other idea?

whunter · #44 06-21-2011, 09:17 PM

Refrigerant Capacity

1300 grams = 3.48283 pounds

When you have the system charged correctly, STOP..

NOTE: If the mono valve is damaged or failing to get a solid ground + 12v = the 80° C heat will be blasting directly into the evaporator.

The A/C system can NOT overcome the heater..

As a diagnostic test:
Gently pinch off the auxiliary water pump hose and check the A/c output temperature..

.

vstech · #45 06-21-2011, 09:38 PM

Looks like everyone got you under control.
glad you are going to replace the receiver. it's even better if you have a specific volume nitrogen tank to keep the moisture out of the system so when you FINALLY after everything is assembled, are ready to put in the receiver last, there is minimal air and water in the system for the vacuum pump to remove.
then as quickly as possible take the seals off the receiver and squirt the correct amount of oil in there, then attach the lines securely.
then pressureize with nitrogen and verify leak free.
then evacuate properly.
for me, evacuate properly means to bring the system down to 1500 microns, then break with refrigerant, reclaim that, then evacuate down to 1000 microns, then weigh in the exact amount of refrigerant.

this is why the evacuation step should be performed by a qualified shop. not many home garages have the equipment to do a proper evacuation.
if you don't have evacuation equipment, the car should be delivered with 100 psi nitrogen in it to a shop that can do it right.