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low side frost

eagle on Wed August 16, 2006 8:56 PM User is offline

Year: 1983
Make: AMC
Model: Eagle
Engine Size: 258
Refrigerant Type: 134a
Country of Origin: United States

I put in 24 oz - 134a into my system & it ran fine but leaked out by the next day. Compressor wouldn't engage but did when I added 24 more oz 134 to the point of just starting to sweat at the low side tubing at compressor. Now I am dripping fluid by the trans. which I believe is coming from the overflow hose in evaporator housing. Have I got too much 134 in or is the white frosted tubing normal? Have I got a serious leak by the evaporator etc. or can I run this possible overflow out of there by letting it leak?

Chick on Thu August 17, 2006 6:26 AM User is offlineView users profile

You have to find out what is leaking. (and exactly where) If it's just condesate from the evaporator, it's normal and will leak more on days that are more humid. If it's anti-freeze, you have a heater core leak. But..where did the first charge go?? If the refrigerant keeps leaking out, you need to find and fix the leak. It won't leak on the ground like water does, so you may need a professioinal to find it for you..Hope this helps.

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

eagle on Thu August 17, 2006 3:25 PM User is offline

Thanks - I seem to have solved some problems but have (2) questions. My frost problem is gone if I keep the control off HI-Cool. The condensation & compressor failure to cycle are OK now by driving the car in traffic rather in the garage with a fan. My question is that the new compressor makes a loud grinding noise when first starting up when cold. After that only a click from the clutch can be heard when restarting or cycling. Is this possibly an oil problem? I evacuated twice & charged twice. Is there a way to use some kind of dipstick in the compressor to check system oil? Also the inside temp = 42 degrees, outside = 81 degrees. How can it run this good with a low side pressure of 26 psi and high side of 25 psi. Thanks

Chick on Thu August 17, 2006 6:27 PM User is offlineView users profile

it can't, you need to get a better hose set, or be sure the wheels are closed, or try pressing down on the high side port (If R12, then screwing it in further). But since you retrofitted it, I would suggest backing out the shrader valve a bit to be sure it's depressing it all the way. See a lot of this lately with harbor frieght gauge sets, but the cheap screw over old shrader valve R134a fittings can also cause this...

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

eagle on Fri August 18, 2006 4:04 PM User is offline

Well my compressor has quieted down and my manifold hoses are tight & giving me accurate readings. The problem is those readings. I've got 84 psi on both low & high sides when the AC is off. When the AC is on I'm getting 120 psi again on both low & high sides. The low side 120 is at the "retard" mark on the gauge. Does this mean I have too much refrigerant in the system? Thanks.

rbinc on Fri August 18, 2006 5:46 PM User is offline

84 psi equalized with the A/C off is not an issue.

If the clutch is engaged when you measure 120 high and low, and you have at least cool air, I suspect you are opening both valves on your manifold. Both should always be fully closed when you are simply observing pressures. When you connect hoses to service ports, you are connected directly to the gauge; opening high or low valves is only to add or remove from the system. If you have both open, the high is overiding the low pressure in the gauge manifold body and this is why you see the same reading. 120 would be low on the high side, but that is an issue to address later once we are certain you are measuring pressures correctly

Make sure both valves on the manifold are closed and try this again. But if you are reading 120 with both closed, you cannot possibly have cold air. If this is the case(no cold with actual 120 on both sides) we are going to have to start from scratch on the history of your project and what you have done.

Regards

k5guy on Fri August 18, 2006 6:05 PM User is offline

It does sound like the valves are open on the manifold.

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Chick on Fri August 18, 2006 7:30 PM User is offlineView users profile

Quote
Originally posted by: eagle
Well my compressor has quieted down and my manifold hoses are tight & giving me accurate readings. The problem is those readings. I've got 84 psi on both low & high sides when the AC is off. When the AC is on I'm getting 120 psi again on both low & high sides. The low side 120 is at the "retard" mark on the gauge. Does this mean I have too much refrigerant in the system? Thanks.

You say your gauges are working correctly, I have to say they may be, but then you're not working them correctly. Both wheels must be closed to read pressures. It is also dangerous to have the high side open while charging as you can blow the can up in your hand. So get that squared away first. If both wheels are closed, then the manifold set is no good. There is no way you would have "any" cooling with a 120psi low side, period. What brand are the gauges?? How old are they, and most important, are you using them correctly. Turned 'in" to the right closes them...

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

NickD on Sat August 19, 2006 6:59 AM User is offline

With the typical low side gauge showing -15 to 0 to 250 PSI and the high side showing 0-500 PSI, if both are showing 84 PSI, have to say that both gauges are tracking excellently. -15 PSI is about the same as 30*/Hg to avoid confusion.

If both or even one valve is open, what is the yellow hose doing at this time? If not connected, and either one or both valves opened, refrigerant would be pouring out. When just checking pressures, leave the yellow hose in the box, but make damn sure both valves are closed before connecting them. I mean you want to check pressures, not dump your charge in about 2 seconds.

Guess I would have to see with my own eyes what is going on, just doesn't make any sense why the static pressure would increase with the engine running unless the compressor is not rotating, and the heat of the engine is increasing the static pressure.

With the posted pressures looking at an ambient range of 95 to 170*F that looks about right, willing to bet the compressor is not rotating.

eagle on Sat August 19, 2006 2:43 PM User is offline

Thanks alot for your help on this one year project guys. Almost done but not quite. Today I started the engine & while it warmed up I put a thermometer in the far right AC outlet, closed the hand valves on the manifold gauge set - removed the yellow service hose from the manifold & purged the other two. I then connected the two hoses to the low & high side valves in the suction & discharge lines - tightened down the valves in the hoses to open the schrader valves & got the following readings: 74 psi Low & 73 psi High. I then turned on the AC to Max. cooling with blower on low. Readings went to 17 psi Low & 133 High. Thermometer temp. inside the car went down to 42 degrees with outside temp @ 80 degrees. When I shut the AC off both gauges went to 59 psi & eventually went to 74 psi. Condensation pours out of the evaporator core at 6 drops per second inside the garage with AC running. Outside after a 5 minute ride & stopping the car it takes 2 minutes to start pouring out condensation again. Compressor cycles off for 20 seconds with AC in AC position, not Max AC position. I'm really only concerned about an overcharge. Although the evaporator core was rebuilt (new inlet pipe & pressure tested to accept 134a) it is still 23 years old & designed for R12. I don't want to put extra pressure in it. I worked with 4 cans of refrigerant - didn't get it all in there - thought I had a leak (no way) - suction tubing sweating but not the compressor - but I still feel I must have 3 cans in there. I hate to take it all out & start over again - its too close to being perfect as far as the 42 degrees goes. Are the above readings acceptable or do they indicate an overcharge? Thanks

Tennessee_Timmy on Sat August 19, 2006 3:42 PM User is offlineView users profile

hi side pressure of 133 with ambient temp of 80. your hi side ought to be roughly about 2.3 X ambient temp.

so, nope, don't believe you're overcharged.

your original post mentioned your 134 leaked out in a day. looks like it's doing it again.


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Good Luck 2 ya,
Timmy

rbinc on Sat August 19, 2006 6:42 PM User is offline

Unless you have lost a significant amount of refrigerant connecting and disconnecting your gauge set in the last 24 hours, you have lost 10 pounds of pressure when the system is equalized (A/C off - static pressure low and high after 10 minutes) at the virtually exact same ambient temperature, your system is most assuredly leaking.

It doesn't appear that you have a means for recovery, so you really should take it to a shop. Have it recovered, have dye injected and re-charged. Purchase a UV detection kit while they are charging with dye. Drive it as long as you can the same day with the AC on max. At least 25 miles. Go home and use the UV lamp and the instructions with the kit to find the leak. You are leaking fast enough that you should find an area where the dye shows up under inspection. Inspect every component of the system including every square inch of the condenser. Inspect hoses, fittings, drier, compressor (fittings, clutch and body), etc.. If you find nothing aqnd the compressor still engages and you have cold air, drive another 25 miles with max air and try again. The only place where UV inspection won't help is the TXV and evaporator, because they are enclosed in the housing. But you could indeed have a leak there as well. If you find a leak(s), take it back to the shop, have it recovered again, go home, open the system and repair the leak. Then it's back to the shop for an evacuation, go home and charge it yourself. You'll see by this process why we have an average of 10K in tools just to make any money doing this every day.

Beyond that, take it to a shop and have it fixed by a pro. Without all of the equipment we use every day on jobs like this to quickly identify problems, the above is the best and cheapest scenario for the DIYer that I can reccomend at this point.

Best of luck.

eagle on Sun August 20, 2006 10:14 AM User is offline

Thanks again. there is a reason I'm doing it myself. After doing all the installation labor myself, I took it to a big name shop known in Chicago & suburbs for evacuation & charge. They told me the compressor was bad - wouldn't turn on therfore system couldn't take a charge. They wanted $400. I took it home & put a new one in for 1/2 the cost. I took it back & they said it was better but wouldn't stay on long enough to take a charge. They said I needed a new expansion valve or receiver/drier. New expansion valves can't be gotten for an '83 but if I was lucky they could come up with & modify an old one they may have. I told them there is a new oine in there now & the drier is rebuilt. They said driers' can't be rebuilt. Nonsense. They are simply cut open - desicant material replaced & rewelded again. I took it home & found thse shop had bent one of the male prongs of the low pressure switch down 90 degrees & reinstalled the female coupler ontop of it. I tried to bend it up but it broke. I replaced it & the compressor went on immediately & stayed on later when I started charging it myself. The shop was simply determined to get $400 out of me instaed of $140 for an honest recharge. I had given them $50 on account so that's all they will get. I purchasec a leak detector but it hasn't shown any leaks in the engine compartment. If I have opne I'm really not going to enjoy going back into that instrument panel again, I had to drop the steering wheel & remove everthing in front of it & cut open the loom of wires to get everything out of there I needed. This car never had AC before. I think it may be smart to hook up the gauges & let the car sit and watch the daily numbers & go from there.

k5guy on Sun August 20, 2006 11:51 AM User is offline

I would find another shop and get the $50 back.

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eagle on Tue August 22, 2006 11:42 AM User is offline

Are there any DIY'ers out there who have used one of the mastercool U/V Leak Detection products offered by Arizona. I'm determined to find this leak myself. I get the impression that after I have the remaining refrigerant recovered, I can inject dye into the system and then recharge and look for a leak. I can see I'll have to have the evaporator core accessible but the radiator side of the condenser will be a problem also. I've got a feeling my problem is with one of these two. I do have an electronic leak detector and as long as I have to open the dash, I suppose I should use it first around the evaporator housing etc. before using one of the U/V products.

theoilwelldoctor on Mon August 27, 2007 3:58 AM User is offline



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Jeff
Tucson, AZ

theoilwelldoctor on Mon August 27, 2007 4:53 AM User is offline

Hi eagle,

Think you are getting some good advise from the forum. I would take my business elsewhere.

I had a similar problem with my old Jaguar. I was lucky but managed to find the owner of a shop in Tucson that was interested in helping me fix the problem.

What I wound up doing was having him evacuate and recharge the system after making his recommended mechanical changes myself. Between the two of us, we solved the problem and I saved some $. All he was charging me for was his base charge of $50.00 per visit. BTW, he recycled my R12 and I was only charged for what leaked out (I guess that was unusual too). Anyway, the final result was a system that was working as it should. The caveat was knowing the repairs were done right.

I have a newer Jaguar now and both of us have spent considerable time finding the leak. Turns out to be the condenser and I plan to buy a parallel flow condenser from the host of this forum when I get back.

Mind you, all this work was done in the winter as the shop owner has to pay the bills in the busy season (all he does is auto ac). He couldn't afford to fool with an old perfectionist with a temperamental car during the summer months when most of his profit is made.



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Jeff
Tucson, AZ

mk378 on Mon August 27, 2007 9:39 AM User is offline

A leak that large should be not too hard to find with a good electronic detector. You don't have to have a full charge to use it.

The Mastercool kit is good to have but if you want to get started right away you can buy a can of 134a with UV dye included and use it to top up the remaining charge. Dye only works while the system is running with a full charge, so do that. Often it can be seen in the daylight if it's a big leak, or buy the UV light separately. The UV light is best used in the dark or indoors and the yellow glasses are quite useful to protect your eyes and improve visibility.

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