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Accumulator fittings...tight quarters!

alchemist_bobtilton on Fri June 27, 2008 7:46 AM User is offline

Year: 1998
Make: Chevrolet
Model: Suburban
Engine Size: 5.7L
Refrigerant Type: 134a
Country of Origin: United States

Guys,
Wondering what tips there might be for taking off the accumulator fitting that buts right up against firewall. Best practice is to try to get two wrenches on the thing (one on the fixed accumulator hex and the other on the evaporator hose fitting (that turns), a 27mm fitting. It's almost impossible to get two back there, let alone one. Any special tools here? also, no way one can torque to specs on this accumulator, given the location?

Thanks-

GM Tech on Fri June 27, 2008 12:00 PM User is offline

If you can't break it loose- don't force it--- Galvanic corrosion has set in and you are better off not to chance it-- you might pull the threads off the evaporator-- and that is a dash pull to replace thge friont evap--- I don't change accumulators unless oil is contaminated.....

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

alchemist_bobtilton on Fri June 27, 2008 1:01 PM User is offline

OK, I won't force it. I put some modest torque on it, but it's really hard to hold the accumulator fixed nut (that would be proper way to do it). However, I was able to easily loosen the other hose connection on the side of the accumulator - it's just the one in back that was problematic. I don't really see what damage I could do to the evaporator, long as I hold the accumulator nut. Threads on the evap are steel, the ones on the accumulator are aluminum. Sprayed just a little PB blaster up in there but couldn't free it last night (turned dark). When I pulled the orifice tube last night, it was clean. Oil was a little dark, but from what I gather on PAG-150, when the system leaks or gets a little moisture, that is typical.

GM Tech on Fri June 27, 2008 1:06 PM User is offline

If galvanic corrosion has set in the steel threads on the evaporator will adhere to the aluminum threads of the accumulator- and tear all the aluminum off the old accumulator- making it impossible to thread onto the new accumulator-- the old accumulator will be void of the threads- because they are in the steel (poorly plated) nut.....it is plated to avoid this issue- but steel and aluminum don't get along- that is why "never-seize" was invented....

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

alchemist_bobtilton on Fri June 27, 2008 1:45 PM User is offline

I see some folks use a Dremel with success, and I've got a surgical type (the extension wand). Thinking about nicking/cutting the accumulator fixed nut to free the evaporator steel nut. This approach works well with exhaust parts, but I hear you on the electrochemical bond betw. aluminum and steel. Not good. Stainless would be even worse. I hate putting a new compressor on without changing out accumulator and o-tube. Sort of like taking a shower and putting dirty underwear on.

kurf on Fri June 27, 2008 7:47 PM User is offline

Hi, I have a 98 Tahoe 5.7, the accumulator is as you described. I have a set of GM Service Manuals and it said not to change it unless it has corrosion or leaking. I changed my compressor, because it was making some noise after running for awhile. After looking at the Orf. Tube I decide against muscling out the accumulator. At this point, the change out worked out well. I tore the old compressor down today just to see what kind of shape it was in, everything looked good to me,no signs of wear or metaltics. The manual also said to add 3 oz. of oil and 8 oz of 134a to see if the noise went away. I didn't do that. I didn't get any oil out of the compressor when I changed it off but after tear down, the compressor looked to have ample lubrication. Time will tell if I did the right thing.
Kurf

GM Tech on Fri June 27, 2008 10:05 PM User is offline

Rest easy - I do it daily.......

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

alchemist_bobtilton on Sat June 28, 2008 12:17 AM User is offline

Great news...used the old dremel and notched a couple of lines on the accumulator nut. Apparently enough to break the evap hose nut loose. Threads look good, just a little crud. Folks talk about Never-Seize. Haven't used it, but Loctite might make something similar. Where can you get this stuff?

Thanks-

mhfd112 on Sat June 28, 2008 9:18 AM User is offline

I always use anti - seize. I think it is made by loctite. It is in a gray bottle. One bottle will last long time.

I have ran into the same problem you had a couple of times. I use a small hacksaw and cut a line across one of the flat sides of the nut. Worked good both time.

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