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Discussion Starter · #1 ·
Hello all. I am starting new thread sorry if not supposed to. I have replaced bad condenser on jeep and in process now of pulling vacuum before refilling condenser oil and putting freon in.

I have manifold gauges blue hose on low side and red on high side with yellow to vacuum pump. I am getting no vacuum at all. Left overnight and nothing.

Oil level on vacuum pump is above the halfway full mark actually almost to full. If i take hoses out I feel suction, just nothing if i connect. Also, nothing goes into low side and nothing comes out. I tried pumping compressed air into it but its like closed off. Also no suction through there either. It's a 91 jeep so not sure if thats the years design how the compressor operates. I have seen videos mainly on 95's ac compressors how to charge, fill with oil and pull vacuum but this one seems to be different. Ideas. Suggestions please. Thanks
 

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Discussion Starter · #2 ·
Also, not sure if this matters but i am using the manifold gauges that just snap on. There is not turning dial on them that some gauges have to depress the shrader valve, but I do think they are depressing the shrader valves in compressor fittings.

I am able to pump air with air compressor using gauges through the high side, but not low side. Another note is this car does not have the service ports on the suction and discharge hoses so i am servicing straight from the compressor valves low and high sides. The vacuum pump I have is the Vivohome brand.

I have put freon in car before and as always, with car on and ac on full blast. Would car need to be on with ac on for ac clutch to engage and pull in through the low side or high side? I believe one is not supposed to charge freon on the high side.

Am I correct on trying to pull compressor oil through the high side? I am trying to add about 2.6 ounces of pag oil into compressor, but I want to vacuum first. Thanks again
 

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First thing I would do is test the vacuum pump. Just put your finger over the end of the hose and turn it on. You can also see if you can pull a vacuum hooked up to the engine at idle. If not, better check those fittings and hose connections
 

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Discussion Starter · #4 ·
Hi yes i put finger on all ends and there is suction. The pump is brand new, first time using it. What I have seen on videos is with vacuum pump on, the blue side manifold gauge is closed off while the red one is open and the yellow one of course from manifold to vacuum pump. The guy then takes off the blue hose at the manifold gauge while leaving the end that attaches to the low side compressor attached and oil is sucked in via the blue side as he was putting PAG oil into ac compressor. When I do the same, there is no suction on the blue hose on the end that attaches to manifold gauge. But if i open the blue side valve and leave that end on manifold, and detach from compressor, I do feel the suction. Its like something is blocking that low side. But then again, the red side seems to be fine as it takes compressed air in. But after leaving that side open all night, no vacuum through there. Maybe both have to be open? Thanks again
 

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the way we always did it was to open all the ports and pull it down that way. That way you pull the whole thing down at once. Then close the valves and see if it holds vacuum
 
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Discussion Starter · #6 ·
Ok. So it turns out this model's compressor has two on-off valves. One on top of compressor by high port for red, and the other, which I missed, right below for low side, blue. They are little shut off valves which you turn opposite way to open and close. Turn left , it closes, turn right it opens. This is to allow freon or other things to be put in compressor. That explains why nothing going in or out of that low blue port. I opened it now good.

They can be turned with 1/4 inch wrench.

Now i pulled vacuuum with both blue and red man gauges attached and open. . Blue side Got to about 31 green area. However, pressure begins increasing almost immediately after closing valves and turning off vacuum.

I pulled vacuum again and closed everything and pulled blue man gauge hose from compressor port and not losing vacuum now. Could it be the man gauge valve and or retro fit valve maybe pressing too far in? It holds vacuum if i pull the blue hose from compressor.
 

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Discussion Starter · #8 ·
Ok, so left it at 30 vacuum overnight isolated no hoses attached. This morning lost all vacuum. Now I'm not sure where leaking from. I done a compressed air test , sprayed hoses, fittings, attachments with soapy water but found no bubbles. Also, I dont lose compressed air pressure.
I have also sparayed with soapy water right after pulling vacuum but no bubbles. Could it be its leaking through port but so slow that not producing bubbles? I also tried closing those two valves mentioned but still lose vacuum. Thanks again.
Yes that's what i am using. I close both valves at the gauges. Begin to loose vacuum though. I just want to eliminate possibility that it's leaking out the ports I guess. Maybe I have rhe wrong idea on how to do that. Thanks
 

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Discussion Starter · #9 ·
Seems the compressor shaft seal may be leaking. I think i got the compressor specs so i can order the shaft seal and see if i can replace. Barely able to read "sanden" and seems the 709T is the identifier as marked on the compressor. I'm waiting for the part. Now as i try to get to the seal, I'm not sure if clutch is supposed to slide off the splines by hand or if special tool required? I looked it up and some say slides off., others use a puller thing. Ideas, suggestions. THANKS.
 

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There is also an O ring for the face you may need to replace. Another for ther rear plate if you want to do the whole thing while you are at it
 

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Discussion Starter · #11 ·
Ok. Good news, I hope, and not sure yet if bad news.
Good is that I got to the seal safely. Autozone had the clutch hub and pulley remover tools for rent. So pretty easy pulling parts out to access the seal. About $110 deposit.
The bad that I'm not sure what to think yet, I didn't see what I expected to see to indicate that the seal was actually bad and leaking. Looking at the felt dust cover right outside the seal, it doesn't look or feel wet. The o ring\gasket between head and housing looked im decent shape. I see oil in the housing area behind the head plate, but is probably normal? Then again, the shaft where the seal sits does look black and i can even say there is a little bit of oil just immediately if where the seal sits on the shaft.
There is also an O ring for the face you may need to replace. Another for ther rear plate if you want to do the whole thing while you are at it
Yea they come with the kit.
 

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Oil in the crank case is normal. If you buy a new Samden compressor, it comes with all the oil for the system in it. It gets pushed out past the rings with use as the crank case becomes pressurized
 

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Discussion Starter · #13 ·
Got the parts and will be installing tomorrow. If it should still leak vacuum, is it possible that the service valve/s are bad? When valves were seated all the way clockwise, that isolated the compressor. But did it expose the schrader valves also? Or were schrader valves taken our of the equation by seating them like that, hence completely isolating compressor from other factors?

Also, is it possible that there is a leak through the actual stems that you turn to back and front seat the service valves? Just thinking ahead. I will post results hopefully seal fixes issue. Thanks
 

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Discussion Starter · #14 ·
Well, new seal did not fix vacuum leak. And this is because leak is coming from the stems on the manual service valves. The ones you turn to back and front seat. Being that system is retrofitted and has sharader valves, I don't need to have those manual valves, right?
 

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I think you are talking about king valves. If you shut them off, then the valves will not be part of the system.
 

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Discussion Starter · #16 ·
Correct. If I shut them fully counterclockwise nothing will go in. Can't vacuum, charge, etc. But in order to even try and pull vacuum It has to be at least fully seated clockwise, which isolates compressor. But by isolating compressor, I would say that the king valves are being exposed; at least the stems are being exposed . That is where I noticed leak coming out of. There must be some kind of seal or something sealing those stems and if wear out then prone to leak. Am I making sense? Thanks
 

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Yes. When I fixed up my Jeep and got a new compressor, I eliminated those valves and had schrader valves put on the hoses. Some new Sanden compressors have the valves built into the head on the back
 

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I had my hoses custom made locally at an auto AC shop
 

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Discussion Starter · #20 ·
Put freon in and seems to be all good. Thanks soo much. Now it Looks like i have a bit more troubleshooting. Ac only blows through defrost vents. Ideas? :)
 
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