<o:smarttagtype namespaceuri="urn:schemas-microsoft-com<img src=" http:="" images.ford-trucks.com="" forums="" images="" smilies="" redface.gif="" border="0" alt="" title="Embarrassment" smilieid="3" class="inlineimg"></o:smarttagtype><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:ApplyBreakingRules/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:UseFELayout/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if !mso]>******** classid="clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D" id=ieooui>*********> <style> st1\:*{behavior:url(#ieooui) } </style> <![endif]--><style> <!-- /* Font Definitions */ @font-face {font-family:SimSun; panose-1:2 1 6 0 3 1 1 1 1 1; mso-font-alt:宋体; mso-font-charset:134; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:3 135135232 16 0 262145 0;} @font-face {font-family:"\@SimSun"; panose-1:2 1 6 0 3 1 1 1 1 1; mso-font-charset:134; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:3 135135232 16 0 262145 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:SimSun;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} </style> <![endif]--><!--[if gte mso 9]><xml> <o:shapedefaults v:ext="edit" spidmax="1026"/> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext="edit"> <o:idmap v:ext="edit" data="1"/> </o:shapelayout></xml><![endif]--> I recently took a 2 hr trip down here in <st1:state><st1>Florida</st1></st1:state> in my 86 F150 with no A/C. By the time I got to where I was going I was so hot and so sweaty I wondered why I made the trip in the first place. I vowed I’d have A/C in my truck and started reading everything I could get my hands on and looking at all sorts of info here too.
Now that I’ve figured it out and the truck is ICE COLD I want to help out all my brothers from other mothers so they can be cool too.


Let's ID some A/C parts...



Then you have your compressor...




...and finally the condenser which is located in front of the radiator.


Oh, your low side valve is near the accumulator and the high side valve is on the that connects to the compressor.


I tried just replacing the compressor and the accumulator, and orifice tube since I knew that was the minimum I could do. No dice. Some people have had luck with it but the more I learned, the more I knew my system had suffered what is called "Catastrophic Failure". It sounds as bad as it is. This happens when the compressor starts to break down and spits metal shavings through the system along with moisture.

The condenser does a good job of collecting the trash in the system before it hits the evaporator but even it has limits on what it can do. This is where our orifice tube comes into play. It's original purpose is to regulate the coolant going into the evaporator however, when the system gets dirty it acts as a filter until nothing can get past it and suddenly you have no coolant flow and NO A/C!


OK


I knew I had a clogged orifice tube so I cleaned it out put it all back together and tried charging it.



Nope.


This is an orifice tube after 15 minutes of running on a dirty system.

 

I read about flushing condensers. Pretty inexpensive if you have the tools. I do not. I don't have an air compressor and I don't have the fancy do-hickey you hook the air compressor to to push chemical flush through my condenser to clean it. Since a new condenser is only $100 I opted for it instead.

To get to it to replace or flush you have to remove the radiator fan shroud, then the radiator and finally the condenser. It's only 8 bolts. Not as difficult as it sounds.
The most difficult bolts to get to, and they're really not that bad are the lower condenser bolts.



Of course good ole Murphy had to come visit and as soon as I snapped the pic of the bolt I broke the clip it screws into. Go figure. Then I dropped the socket i was using in the drained coolant.
Finally got the condenser out! Go have a cold beverage!
I have to go to work and will finish the post tonight but first a couple pics of the new condenser.

 

Most people do not have a vacuum pump to evacuate the system. Where are you getting yours? I always borrow mine from work.

 

You can rent one from Autozone for about $200 on the loan-a-tool program (you get the money back when you return the pump). I opted to buy one from Harbor Freight for $80. They had it on sale that week! Usually it's $90.
Also, if you're going to use the vacuum pump, you need to have the gauges to make sure you're actually pulling a vacuum and not losing the vacuum. Again, loan-a-tool program, I think for $50 or $60 but you get the money back when you return them. I bought those too at HF for $50ish since I figured I would eventually have to do another A/C one day down the road.

 

When I left off I had the old condenser out and the new one ready to go in. I figured since I was this far in I might as well try to clean the hoses so they don't have gunk in them to run through my new condenser. I used mineral spirits to clean the crap out. Some people say you aren't supposed to and some say you can. I'll leave that decision up to you. Do your research and decide for yourself. My air is cold for now so I'm not upset if mineral spirits has any drawbacks...yet.

Here's the new condenser where it belongs.


I decided to check for any debris around the evaporator since everything else in the system was getting attention. After unscrewing all the screws on the outside of the evaporator housing I still couldn't get the cover off. Haynes manual said there was 1 screw, ONE, inside the cab that you had to unscrew in order to remove the cover. After removing the dashpad to try to see it, I found the 1 screw under the heater.
Here's its location so you don't take apart the cab like I did. I hadn't replaced it yet when i took the pic but you see where it goes.


Inside the housing was enough crap to make about 3 good sized bird nests. Glad I did that.
Also the first time I ran the system, back with the old condenser I put 8oz of Pag 100 oil in the system. I split it between the accumulator and compressor. Then I bought 134a from Wally world since its $2 cheaper per 12 oz can than the parts stores.
When I lost the charge and had to open the system again because of the orifice tube blockage fiasco I lost all that oil. I thought I may have retained some but when I turned the compressor upside down to find how much more oil to put in, about an ounce came out. It barely filler the bottom of my Bondo lid.


So I got 8 more oz of PAG 100 oil and split it again between the accumulator and compressor.

OK now it's time to put everything back together.
I have a new accumulator. $35
A rebuilt compressor. $75
A new orifice tube. $2
A new condenser. $100
A new cycling switch. $15
New green o-rings for every fitting. VERY IMPORTANT!
And clean hoses to put it all together.

Just so you know...
I read that if you buy hoses designed to carry R12 and run 134a through them they leak because the 134a molecules are smaller. It's ok to run 134z through hoses that have held R12 since the coolant coats the tube lining or something like that. Hoses designed for 134a have a lining in them that prevents the molecules from escaping.

After I put everything together I hooked the vacuum to the system and it held -30 on the low side for 1/2 an hour. Then I turned off the pump and it continued to hold the vacuum for another 1/2 hr.

Time to charge her up! It took 2 cans to fill the system to make the air cold. It was 93 outside and blowing in the 50's in the cab. The Haynes techbook says an 86 F150 should have a low side pressure between 24-50 and a high side of 160-250.

Tonight coming home from work I blasted the A/C because I haven't had it in so long and the cab was at 59 before I finally gave in and turned it off.

 

I think this deserves to go into the Tech forum.

 

Opinions on this vary also. I am like you, and usually only put the vacuum on the system for about 30 minutes to and hour, but some people like to leave the vacuum pump on overnight. You are getting the air out of the system with the vacuum pump, but what you are also doing is getting the moisture out. Any moisture laying in liquid form inside the system will start boiling and turn into vapor when it's under vacuum. And then it makes it's way out via the vacuum pump. The longer you leave the vacuum pump running, the better job it does getting the moisture out.

 

There is already a good A/C thread in the Tech Tips.

-Enjoy
fh : )_~

 

True although I don't think you have to have the vacuum on for more than an hour. I turned the pump off after 30 minutes to check for leaks. If the system can't hold the vacuum at -30 psi then you have a leak somewhere that needs attention. Better to be frustrated and have to find a leak before you fully charge then to lose the coolant, lose more money, be really frustrated and still have to find the leak.