Off Roading Forums banner
1 - 8 of 8 Posts

·
Registered
Joined
·
425 Posts
Discussion Starter · #1 ·
Jeep is a '98 with a 4.0. The compressor was kicking on for a few seconds, then shutting off for about 20 seconds consistently. It was blowing warm air, so I tried the cheap, over the counter refill route. After a large can, the air blew cool for a a few minutes, then went back to warm. I checked for leaks with the gauge, and even after a week it was holding up in the 25-30psi range. I read that the quicky auto parts store cans don't really do much, and I needed to get an evacuate and recharge.

HERE IS WHERE I THINK I MADE A MISTAKE!

WENT TO JIFFY LUBE, yes shoot me now. Nice guy got the Jeep in, told me to have a seat in the waiting area. He said for $129.00, he can do the evacuate and recharge. 20 minutes later the guy comes back, said he couldn't charge it because it has a leak. No problem, I paid $30 for a check, plus through the guy a tip.

I go to pull away, and it feels like my auto tranny is slipping. I notice that the a/c is still on, and I am getting a violent "machine gun" sound. Get it to the next corner, and the engine is covered in green slime. When the compressor is kicking on, its shooting freon from a valve on the center back of the compressor, hitting the firewall. I immediately shut the compressor off, wiped down everything and went home. I googled the problem, and found out that the tech might have added too much oil, and the high pressure release valve was responding to this.

As of last night, a week later, the compressor still kicks on, and still spits freon, so I leave it off.

Is it shot, or do I need to just bring it to someone who knows what they are doing? Did the Jiffy Lube guy screw-up?

Thanks
 

·
Registered
Joined
·
556 Posts
You need a good AC person.
The system basicly has two sides, a high pressure side and a vacuum side.
The problem may be a clogged or broken orfice tube that keeps the pressure on half the system hence your guage shows pressure but will not allow a full cycle of the freon. You will need a manifold set of guages along with some knowledge of the system in order to solve your problem.
If you could visualize your system as a garden hose with the water pressure on, a kink in the hose, and a little kid sucking on the end for water. hope this helps.
 

·
Registered
Joined
·
10,815 Posts
Problem to start with -- "Jiffy Lube."

He probably filled it with too much taco sauce - he learned how to do that at his last job 3 weeks ago.

Look at the fittings (2, hi and lo) where he connected his pump and gauges - he may have twisted the aluminum line when he connected to it, causing the restriction. Or he could have got dirt in, plugging it. It has to be very clean!

Since it held static pressure before he messed with it, where'd the leak come from?

Find a real shop.
 

·
Registered
Joined
·
6,870 Posts
OK,
High Pressure side.
High pressure coolant from the compressor goes off to a 'nozzle', much like an air tank goes through a hose to an air nozzle.

The 'Nozzle' is called an 'Orifice' in an air conditioning system.
High pressure escapes through the Orifice and expands.
(like compressed air gets the nozzle cold on an air compressor...)

During expansion, the expanding coolant absorbs heat from the atmosphere to power its expansion.
(The result is lack of energy in the form of radiated heat, or 'Cold'...)

The 'Cold' (or actually lack of heat energy) is passed to the cabin air in your vehicle by the 'Heat Exchanger' under your dash.

If that 'Orifice' (or Nozzle) gets a piece of crap in it (like from a compressor coming apart internally) you will not get effective 'cooling'.
----------------------

After expansion and heat transference, the expanded gasses are returned to the pump to be compressed again.
-----------------------

If you have 'high pressure side' but no 'low pressure side' , the Orifice is plugged.
If you have low pressure on the 'high pressure side' you have a leak or the system is way over charged.
The 'Snap', 'Snap', 'Snap' you heard is the low pressure cycling switch trying to protect the compressor... Too low of pressure on the high pressure side of the system activating the switch and stopping the compressor...

There are safety switches in the lines (on modern AC systems) to protect the compressor in the event of low pressure (Low pressure cycling switch = Too little 'Freon') or too high pressure (high pressure cycling switch = Plugged Orifice or kinked line).
------------------------

Since you added 'Freon' and the system cooled down, the system is working, but has a leak.
Most leaks are from degraded 'O' rings between connection points or at the compressor shaft seal.

The 'Goo' it's self is probably an additive put in the system (harmless) by the shop guy to help highlight the leak in the system.
A very little bit of the dye marker goes a LONG way, so it looks much worse than it is...

Some use a highly visible dye you can see with the naked eye, some use an ultra violet dye you can only see with a 'Black' light, There is an Infra-Red version, ect.

The 'Goo' your system is leaking is from a sticking Schrader valve.
(The guy would have had to put in several pints of dye for it to over pressure the system and activate the over pressure burst disk...)

The Schrader valve is a one way valve, just like the one in your vehicle rims to inflate tires through.
That valve is supposed to have a leak resistant cap...
 

·
Registered
Joined
·
425 Posts
Discussion Starter · #5 ·
I pressed in both sides, high pressure air/freon came out. The green goo is only coming from the high pressure valve, no where else. The compressor is still coming on, although it does not sound as healthy as it did prior to going to Jiffy Lube.

I guess the question is...do I need a new compressor, or have it redone properly? Assuming that the "tech" loaded to much freon/oil into my system, and that I shut it down right away, can I assume the compressor's over/underload valve protected it from being damaged?
 

·
Registered
Joined
·
10,815 Posts
Lots of PAG oils are bright green. I wonder if the "auto parts can" you used had extra oil in it - it is possible to put "too much" oil in the system. It won't have enough room for freon in that case.
So many times a tech adds oil when he shouldn't. If the freon just leaked out slowly over time, and oil didn't leak out with it, no new oil should be put in.

Also wondering - many gauge sets need an adapter to connect to the Hi side (especially when the system was R-12, but now is R-134. I'm wondering if he left his adapter on it, and that's what's leaking. Have a close look, it's a little screw-on fitting on the line - it's a fitting on a fitting - both have the schrader valves in them. I seem to lose mine like that all the time. The adapter has a valve in it that pushes on the valve underneath it, making 2 valves in a row. Almost a garanteed leak.


If the place where it's leaking out has the valve on it and it's on the compressor - like a tire valve, that's the Hi side - easy to fix. If it's a plug looking thing on the back of the compressor it's the overload pop-off valve (like a fuse in case the pressure goes way too high,) indicating the system's badly plugged.

I doubt your compressor has gone south.

BTW - clean-up of the PAG oil - spray 409 around - let it sit a moment, hose it off.

Since before you took it in you said it held pressure of about 30 lbs (engine off I assume) for weeks, it probably doesn't have a leak other than that fitting.

Be sure to wear safety glasses - even a small shot of freon in the eye can blind you!
 

·
Registered
Joined
·
1,806 Posts
Hopefully none of the board members work at one, but... NEVER, NEVER, TAKE ANYTHING TO JIFFY LUBE!!!!! I can't even count the number of things I've seen happen as a result of their flunky service techs. Stay away and pay little more for a piece of mind. Sounds like it's time to have someone with a little better rep get your AC system back up and running properly. Who knows what type of oil the jiffy flunky put in, or if he/she even used the correct refrigerant. Sounds hard to screw up, but from what I've seen them dish out... /ubbthreads/images/graemlins/shocked.gif.
 

·
Registered
Joined
·
6,870 Posts
Rich is correct about the adaptors, I used to have a decent collection of adaptors where people had been somewhere else and showed up with adaptors 'Leaking' the freon off...

If they didn't put the 'O' ring cap back on the valve, it's almost a dead give away there is still an adaptor on the fitting threads...
----------------------

Lots of the 'Do It Yourself' kits have the oil already in the cans that come with the hose, so you have to watch for that.
Most of the dyes used are oil mixed, so there is some more oil in the system...

Good idea to take it to a real shop and let them have a wack at it.
Tell them, in detail, everything that has already been done so they don't waste time backtracking.
 
1 - 8 of 8 Posts
Top