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2005 f-150

PostPosted: Tue Aug 09, 2016 8:07 pm
by nc-fordguy
Greetings all

2005 f-150 5.4

I've replaced the compressor, condenser, accumulator/drier and oriface tube and charged the system to specification.

Ambient temp was around 90 degrees with 90 percent humidity. Guages are reading 50 low and 140 high.

The compressor is not cycling(old one did cycle), warm air coming out of registers (78 degrees) and the high side pressure line gets to hot to touch. The battery was removed to access and change the accumulator/drier.

I'm out of ideas at this point.

Suggestions what to do/look for now?

Re: 2005 f-150

PostPosted: Tue Aug 09, 2016 8:35 pm
by Tom Greenleaf

First off it just looks like charge isn't correct - too low but not so fast.

Did you spin this compressor, vacuum and get at least most of the charge in before running it? That can be missing from steps to charge when ready. Unknown rebuilt or new if info isn't with them with suggestions.

What equipment do you have to know charge is or thought to be correct? Bottle and scale or machine that puts in specified charge automatically?

If you have that and trust it see how much comes out now if it's what it said it put in. If not it leaked so some connection or anything still could leak that fast new stuff and all.

So need to really know charge is correct and if not why. Then I think you have to blame the compressor,


(add in info) This info is here up top but here's the link to it......... > ... Procedures < Full of good info on charging <

Re: 2005 f-150

PostPosted: Wed Aug 10, 2016 8:24 pm
by Nacho
Orifice tube not properly seated or installed backwards.

Re: 2005 f-150

PostPosted: Wed Aug 10, 2016 10:58 pm
by nc-fordguy
Oriface tube installed correctly.

Compressor is a re-manufactured "Murray" brand I got from O'reilly auto parts. The freon was installed via manifold gauges and a scale. I did not spin the compressor.

Both of my trucks a/c systems died at basically the same time. The other being a 2003 7.3 powerstoke. I repaired the 2003 first and followed the same procedures on the 2005. The 2003 a/c is working just fine. This in part adds to the confusion on the issue with the 2005.

I'm guessing I got a bad remanned compressor?

Re: 2005 f-150

PostPosted: Thu Aug 11, 2016 6:04 am
by Tom Greenleaf
OK - What did the old "O" tube look like debris wise? How are you so sure it's now correct - same question?

Not spinning oil thru a new (reman or new) and charging slowly if so you are burning up a compressor dry of oil trying to draw/suck in refrigerant. You must have pre-lube and as much charge into a well held vacuum FIRST before starting up and letting the vehicle suck in the finish amount of gas.

Oil doesn't move until there's enough charge to cool some in a system. You can just have a couple ounces in most systems and enough static pressure to allow compressor to think there's enough pressure to try and it should shut right down or "cycle" off when pressure is found too low or if thermally sensed out of spec.

Engine off into a vacuum you should get quite a bit of a charge in with source container warm enough counts and how full it is or it will equalize quickly.

IDK - almost all systems are late to shut down from new vehicle if just a low charge from any leak for any reason I find. If you catch them they can last forever but it's temperate where I am yet easily spike over 100F many time this year for example just not for long.

I simply can't know brand by brand reman or new what a compressor had actually had done to it or how long ago so they are spun with oil before even installing to prevent instant burn up for lack of lubrication.

You don't have much time to get enough charge in is what I'm saying.

Hope that it is the "O" tube. You seem sure but pressures are not consistent with it or perhaps charge being correct.

That or compressor just can't "compress" nor draw in well from low side already or never was right. Debris found now would be a bummer but tell what happened,


Re: 2005 f-150

PostPosted: Thu Aug 11, 2016 8:01 am
by nc-fordguy
Ok, I'll repharase my statement. The O-tube was put in correctly based upon my experience a few other systems I've repaired. It appeared to be at the same depth as the one I removed. The old O-tube had some metal shavings in it and some sort of what appeared to be some sort of fiber that I can best describe as carpet fiber.

My initial diagnosis with manifold guages with the old system still intact showed a low side of 50 and a high side around 300. This led me to believe of a blockage in the system. The old system slowly lost it's ability to cool at idle and slow speeds and got progressively worse. This is why also replaced the condenser as well. I also during the repair ran some flush through the rest of the lines that were not replaced.

I evacuated the new system with a vacuum pump for about half an hour (robinair 2 stage pump 5 cfm pump. I let the gauges monitor the system for around another half an hour to check for a loss a vacuum. It held consistant at 28 HG. I then added 36 ounces of freon. 5 ounces of oil was added to the compressor to bring the total to spec at 8 ounces.

I did talk to by friend who works at 0'riellys and he did state he does see compressors come back sometimes and he's going to warranty the compressor and replace the reon that is wasted.

My concern here is not the replacement costs as there is none, but more so if there was something I did not correctly do. It's a PITA to remove the compressor as it is accessed from under the truck and Transmission lines and wiring have to be relocated plus being a Contortionist to reach your hands in place.

Re: 2005 f-150

PostPosted: Thu Aug 11, 2016 11:00 am
by Tom Greenleaf
OK - Still didn't answer if you were able to get adequate gas (refrigerant) into this before running it.

Compressor if failed might have done the same bull as the last one and find some junk at "o" tube again or oil dumped out of compressor. Kinda means all those parts new now aren't so good and by rights should go again!

Try this anyway while intact: Check static pressure vs this chart with real accurate temps known, cold engine just to see if temp matches pressure or close. Chart............

This could show you lost refrigerant already. A known good touchless infrared thermos would really be needed to know temp then you know pressure and vs verse with known contained gas.

If off it's not impossible to have leaked badly - gauges while charging or the system new parts or not. Stinks.

Nothing is easy to get at and lucky you could undo stuff without breaking the next item down the line and might have so rule out leakage and even with a free exchange compressor may not solve this without possibly needing all you did again and more if a leak on something not replaced but connected.

Current pressures suggest it's doing something and really would expect a lower low if low charge which is why Nacho (total pro at this stuff) suggested an issue with "O" tube so quickly and makes some sense.

Spin compressors with oil before installation. I can't have a clue how long it sat or what was done before suddenly engaging if totally dry is harsh instantly.

Belt it tight - right? Not slipping at belt or clutch from a mess or anything else to throw off the diagnosis?

Just in general quality of parts is disappointing and I've been done with this stuff and general work for quite a while now just what I need for myself and in no time parts stink IMO.

Any which way this could be a real bummer and starting whole thing over again, contortionist acts and all.

Good luck. Test what you can while intact then choose your approach based on best info you can gather,


Re: 2005 f-150

PostPosted: Thu Aug 11, 2016 9:24 pm
by Nacho
If you did everything correctly, things point to a defective compressor.

Re: 2005 f-150

PostPosted: Fri Aug 12, 2016 2:54 am
by nc-fordguy
Had some time tonight and went out to the shop.........

Now the compressor is locked up' Back to square one again.

I did pull the orifice tube out and it was oriented in the correct direction.

Re: 2005 f-150

PostPosted: Wed Aug 17, 2016 6:29 am
by nc-fordguy
Well I got the new compressor in and for gp I replaced the orifice tube. The old compressor was locked up locked up like an ancient chastity belt.

Now it's not holding vacuum which I suspect is at the compressor seeing how it's accessed under the truck. The 100 plus degrees days hasn't really motivated me to get back under the truck

Re: 2005 f-150

PostPosted: Wed Aug 17, 2016 7:03 am
by ACProf
I didn't see any info on the Orig OLD compresssor before you replaced it.
I also didn't see any indication that you flushed out the system before installing the new parts.
Q: Was the orig compressor operational or had it failed?

I would be VERY interested to know why the replacement compressor locked up.
If its because of ingestion of metal debris in the system from the last compressor failure, you could expect the same results from this second replacement.

Hope I'm wrong!


OK, I went back and resd the earlier posts. You said you did run some flush through the system that wasn't replaced.

Wish you good luck with this second compressor.