A/C questions upon installation of compressor

[JerryHughes]

Oh, one more thing. On Wolfman's spec sheet, it says to tighten the bracket bolts on the compressor (front to 40 ft. lbs and rear to 19 ft. lbs.) but I'm not sure which ones he is referring to. There are six bolts, three large and three smaller, that hold the compressor to the bracket, not to the engine. Do I tighten the large bolts to 40 and the small to 19? Thanks,

Jerry

[OldNuc]

Nothing has an easy answer.

Front bracket to block = 40 ft-lb those are the big ones
Rear bracket to the block and head = 22 ft-lb those are the little ones

A/C compressor-to-front bracket = 36 ft-lb
A/C compressor-to-rear bracket = 19 ft-lb

Or, for most of us, big ones 35-38 ft-lb, and little ones, 18-20 ft-lb. The torque wrench is only +/-4% on a very good day.

[JerryHughes]

Originally Posted by OldNuc

Nothing has an easy answer.

Front bracket to block = 40 ft-lb those are the big ones
Rear bracket to the block and head = 22 ft-lb those are the little ones

A/C compressor-to-front bracket = 36 ft-lb
A/C compressor-to-rear bracket = 19 ft-lb

Or, for most of us, big ones 35-38 ft-lb, and little ones, 18-20 ft-lb. The torque wrench is only +/-4% on a very good day.

Thanks, OldNuc. What has me confused is that they refer to the "back" and "front" but the bolts are to the left or one side of the compressor or the other when looking at the compressor from the front of the car. I'll just tighten the "big" ones to 36 and the small to 19. Thanks!

Oh, and do you think two ounces of oil in the compressor would be right when I only got out a hair over one ounce??

Jerry

[JerryHughes]

Well, I ended up only putting 1 1/4 ounces of oil in the compressor. If someone thinks that is too little, I should be able to add more to the drier to compensate----thinking that that oil distributes itself evenly throughout the whole system??? Thoughts?

Jerry

[OldNuc]

Yes it does. Somewhere it tells you to drain the dryer and replace the oil removed plus a guess for what is on the desiccant. I assume that you did this also.

[JerryHughes]

Originally Posted by OldNuc

Yes it does. Somewhere it tells you to drain the dryer and replace the oil removed plus a guess for what is on the desiccant. I assume that you did this also.

When the drier gets here in 10 days, I will do that. Still can't imagine how you get a good guess off the "innards" of the drier but I'll probably end up with about an ounce---maybe two. But that drier is the one I installed only a few months ago---just before my clutch went bad and at that time I only added one ounce of oil so it will be interesting to see how much I do get back.

Installing the compressor was easy. Only time consuming thing was trying to line the six bracket bolts back up!! Oy, I had a few choice words for those. But it all came together. Couldn't use my torque wrench on the three large bolts because of lack of room so I guess-timated.

The suction line doesn't seem too secure, moves up and down easily even though I used 12 ft. lbs. to secure. I guess I won't know if it's going to leak until the pump is hooked up. Thanks for the info, OldNuc.

Jerry

[fdryer]

Desiccant absorbs water only, no oil. What ever you drain from the drier, use only that amount, no more. The same for the compressor, whatever was drained out, use only the same amount to put back in. Your system is a good example of how oil was distributed throughout the entire system. It would be difficult to prove how oil was distributed unless you're willing to competely flush the entire system and attempt to measure what comes out. The condenser and evaporator coil retains oil as well as the lines and filter/drier. To put in more than whats measured is on the verge of over filling. The only exception to this would be if a catastrophic discharge of refrigerant occurred and a large amount of oil was discharged by evidence in the immediate area. Then you'd have to assume a complete repair with replacement of whatever's necessary and flushing the remaining parts to start over as if a new installation is attempted. A full amount of oil would be distributed for giving the compressor a good chance of immediate lubrication. Unless you have seen evidence of large amounts of oil loss it would be better to follow guidelines. The rules still apply; overfilling of oil leaves less room for refrigerant or you wind up with higher pressures than anticipated because of more oil than necessary that now crowds the closed volume of the system, including the full amount of refrigerant. One or two more ounces oil takes up that much more volume within the system and now filling it with R134a also will cause higher pressures especially the low side as there's less room for expansion to lower temperatures whereas the right amount used will result in the right low pressure readings that translates to correct cooling. Getting creative can cause you some loss of cooling when you're concerned about oil amounts.

The reason for tightening mounting bolts carefully is to avoid stressing the compressor body and inadvertently creating undue load that can translate into a compressor leak.

If you like, go over to http://ackits.com and sign in as a new member and enquire, describing exactly what you're doing. Nothing like advice from the pro's there dealing with a/c issues exclusively. If you're waiting on the drier then you can wait some more before installing the compressor for some better advice on a forum devoted to a/c issues.

[JerryHughes]

Originally Posted by fdryer

If you're waiting on the drier then you can wait some more before installing the compressor for some better advice on a forum devoted to a/c issues.

Thanks for that advice, fdryer, but the rebuilt compressor is already installed. I thought the reason for tightening the bolts to a certain spec was to make sure you didn't strip the aluminum. Oh well, maybe I'll hit it lucky on that one.

The suction line is the one I'm worried about right now. The line itself moves, I mean that I can actually feel the line move even though it's bolted. I hope that changes when there is pressure put on the line. I won't fill the system until the drier gets here of course. I called Saturn to ask if the diameter of the two O-rings that are on the compressor are the same and he said that even though the two rings are different sizes, one larger than the other, the actual diameter of both rings are the same. So I'm fairly sure I have the correct rings. Again, won't know until I fill the system. Thanks again for the help.

Jerry

[JerryHughes]

[QUOTE=fdryer;1317548]
If you like, go over to http://ackits.com and sign in as a new member and enquire, describing exactly what you're doing. Nothing like advice from the pro's there dealing with a/c issues exclusively. QUOTE]

Just F.Y.I. I've been a member at ackits in the past and the info I have gotten from you is just as reliable if not more, than the info I've gotten from that site! Thanks again,

Jerry

[JerryHughes]

I've read that the compressor needs to be rotated about 10 times before operation to clear oil from the cylinders. But should this be done only after the system has been pressurized or can I do that now just by spinning the clutch with the V-belt off? But I don't think that spins the compressor. Should I string a line from my positive battery terminal to the electric conneciton on the compressor to close the clutch gap---then rotate the clutch to move the compressor oil? Thanks,

Jerry

[JerryHughes]

Originally Posted by JerryHughes

I've read that the compressor needs to be rotated about 10 times before operation to clear oil from the cylinders. But should this be done only after the system has been pressurized or can I do that now just by spinning the clutch with the V-belt off? But I don't think that spins the compressor. Should I string a line from my positive battery terminal to the electric conneciton on the compressor to close the clutch gap---then rotate the clutch to move the compressor oil? Thanks,

Jerry

I just answered my own question. According to what I've just read, AFTER the system is pressurized, all I need to do is hand turn the CLUTCH about 10 times before I turn the engine on. Thanks,

Jerry

[OldNuc]

Take a hold of the clutch disk and rotate it that will do the job. the armature disk out in front with the 3 knobs. normally you do that while you are drawing the vacuum for something to do while the pump runs.

[JerryHughes]

Originally Posted by OldNuc

Take a hold of the clutch disk and rotate it that will do the job. the armature disk out in front with the 3 knobs. normally you do that while you are drawing the vacuum for something to do while the pump runs.

Thanks, OldNuc. An email said I will get my drier this Saturday, then it's just fill.

Jerry

[JerryHughes]

One last question. When pulling the suction line out of the old compressor, it was pretty tight and I had to wiggle it back and forth while pulling, to get it out. I didn't look into the suction hole on the compressor but on the edge I saw the old O-ring. I left it in the old compressor when I returned it to Pep Boys for the core.

But when installing the new O-ring over the suction line, I installed it all the way down on the tube. And when pushing the line back into the new compressor, it went in really easily. Is there a chance I left something in the suction hole on the old compressor? As I mentioned in another post, even though the current suction line is torqued down, the line seems a little loose and can be moved back and forth. Or will this tighten up when the system is under pressure? Does the O-ring expand inside there? Thanks for any input.

(And I'm going to go back and loosen then re-tighten the three large bolts that I wasn't able to get my torque wrench on. Then I won't tighten them so hard.)

Jerry

[fdryer]

Something isn't right as there shouldn't be any movement of the line; correct me if I'm wrong here but the line should have a swaged(?) shoulder about 1/2" in from the end of the line for the O-ring to rest on. As the line goes into the female coupler end of the compressor the O-ring should be felt as its squeezed between the outside diameter of the male fitting and the inside diameter of the female fitting with oil as lube. As the two ends fit together the loose nut is screwed onto the fixed fitting forcing the fittings together tightly, now compressing the O-ring as it seats between one flat of the male fitting and the other flat of the female fitting. This tight fit as the nuts are tightened becomes the pressure-proof seal. The O-ring sandwiched between two shoulders and the I.D./O.D. of both aluminum tubes. There shouldn't be any looseness at all and I think this will be a leak as the vacuum pump is turned on. Check this against the high pressure fitting. They should both feel the same when tightening/loosening. I think the O-ring may be the wrong size, the compressor fitting is oversize, or there might not be a completely tight fitting with a space. Although not correct, there may be room for two O-rings? Just writing the previous sentence is wrong. Are the two fittings pushed together as snug before running the nut on?

[JerryHughes]

Originally Posted by fdryer

Something isn't right as there shouldn't be any movement of the line; correct me if I'm wrong here but the line should have a swaged(?) shoulder about 1/2" in from the end of the line for the O-ring to rest on. As the line goes into the female coupler end of the compressor the O-ring should be felt as its squeezed between the outside diameter of the male fitting and the inside diameter of the female fitting with oil as lube. As the two ends fit together the loose nut is screwed onto the fixed fitting forcing the fittings together tightly, now compressing the O-ring as it seats between one flat of the male fitting and the other flat of the female fitting. This tight fit as the nuts are tightened becomes the pressure-proof seal. The O-ring sandwiched between two shoulders and the I.D./O.D. of both aluminum tubes. There shouldn't be any looseness at all and I think this will be a leak as the vacuum pump is turned on. Check this against the high pressure fitting. They should both feel the same when tightening/loosening. I think the O-ring may be the wrong size, the compressor fitting is oversize, or there might not be a completely tight fitting with a space. Although not correct, there may be room for two O-rings? Just writing the previous sentence is wrong. Are the two fittings pushed together as snug before running the nut on?

No, the two fittings pushed together are not snug before turning the nut. Please refer to my make-shift drawing of what I think the male end looked like before I assembled. (attachment) The "horn" shaped end looks funny and exaggerated so I may have that wrong. But there is a groove at the very end where the O-ring seats and that's where I put it, all the way down into that groove. Does that drawing look wrong?

Oh, and would you know if the two O-rings that go on the two compressor lines are the same diameter? Not the overall size but the size or thickness of the O-ring wall? The two I got from the Saturn dealer are the same thickness whereas you would think that the O-ring that goes on the suction line would be thicker. Thanks,

Jerry

[fdryer]

Once again, I was somewhere else with the a/c fittings thinking of an older style of attaching hose ends securely instead of GM's new (to me) fittings. I had to look again at the fittings and realize what your drawing displayed, a manifold type of fitting instead of what I referred to. I would think that the two fittings on the compressor are designed for two reasons; to thwart mistaking one for the other and have two different O-ring sizes. Although I cannot say for sure if there are two O-ring sizes I would be concerned about the suction fitting moving so easily. It shouldn't have any movement at all, like the high pressure side. I would remove the fitting and examine it closely for the wrong O-ring, large nick preventing seating of the two mating pieces, etc.. Saturn may have given you the wrong one as it would be something easily overlooked unless the place you went to does compressor replacements on a regular basis. Then the stock room clerk would know not to sell you the wrong part. An omission. It happens.

[OldNuc]

Originally Posted by JerryHughes

One last question. When pulling the suction line out of the old compressor, it was pretty tight and I had to wiggle it back and forth while pulling, to get it out. I didn't look into the suction hole on the compressor but on the edge I saw the old O-ring. I left it in the old compressor when I returned it to Pep Boys for the core.

But when installing the new O-ring over the suction line, I installed it all the way down on the tube. And when pushing the line back into the new compressor, it went in really easily. Is there a chance I left something in the suction hole on the old compressor? As I mentioned in another post, even though the current suction line is torqued down, the line seems a little loose and can be moved back and forth. Or will this tighten up when the system is under pressure? Does the O-ring expand inside there? Thanks for any input.

(And I'm going to go back and loosen then re-tighten the three large bolts that I wasn't able to get my torque wrench on. Then I won't tighten them so hard.)

Jerry

You have pinched the o-ring between the edge of the compressor housing and the backing piece that holds the tube into the compressor. There is no o-ring grove. It will leak! The way those are supposed to be assembled is you place the 0-ring on the very end of the tube and thew will be a very shallow break in the outer edge of the compressor housing hole. with care you start the o-ring into the housing and let it rill down the tube as it is installed. The o-ring is just rolled between the tube and the hole. Install bolt and torque. Pressure will force the o-ring back to the rear of the ole if it needs to but usually they stay right where they finish up. that is why it was at the end of the tube when you pulled it out. It rolled to the end as you pulled it out. There is no o-ring grove in this system. You should remove the tube and replace the o-ring lube it all up and roll it into place. The trick is to get the tube in the o-ring and the assembly into the hole in the housing at the same time.

[JerryHughes]

Originally Posted by OldNuc

You have pinched the o-ring between the edge of the compressor housing and the backing piece that holds the tube into the compressor. There is no o-ring grove. It will leak! The way those are supposed to be assembled is you place the 0-ring on the very end of the tube and thew will be a very shallow break in the outer edge of the compressor housing hole. with care you start the o-ring into the housing and let it rill down the tube as it is installed. The o-ring is just rolled between the tube and the hole. Install bolt and torque. Pressure will force the o-ring back to the rear of the ole if it needs to but usually they stay right where they finish up. that is why it was at the end of the tube when you pulled it out. It rolled to the end as you pulled it out. There is no o-ring grove in this system. You should remove the tube and replace the o-ring lube it all up and roll it into place. The trick is to get the tube in the o-ring and the assembly into the hole in the housing at the same time.

First of all, thanks fdryer and OldNuc for working with me on this. Very, very much appreciated!!!!

So the groove that I show on my drawing where the O-ring is now seated is NOT for the location of the O-ring. Okay. When I took the old compressor off, I noticed the old O-ring still seated at the very end of the compressor hole and not on the suction line itself. It was very firmly in place and in fact I tried pulling it out with my finger---it wouldn't come out so I just left it in there when I returned that core to Pep Boys.

And when I assembled the other line (exhaust?) into the compressor, I did the same thing. I put the O-ring all the way down on to the line, then assembled and torqued. Should I have done this one the same as the suction line then? When I pulled the old O-ring off that location, it was stuck to the actual line itself, unlike the suction line O-ring that was stuck at the edge of the compressor hole. Thanks,

Jerry

[JerryHughes]

Well then this question comes up. If the O-ring wouldn't be seated until the system gets pressurized, will the suction line still feel "not tight" or be able to be moved a little as it is now---after it's torqued down? Thanks,

Jerry