A/C and/or Vacuum problem?
Thread Starter
|
Freshman User
Joined: Oct 2006
Posts: 37
Likes: 0
Tips and Techniques for Conversion?
The Indie shop suggested using "denatured alcohol", do I have take particular precautions with this method? I was planning on using a flush gun kit with an air compressor.
Lubing the O-ring is done with straight PAG oil (no UV dye in it)?
Any limit on the amount of lubing, or because PAG oil is in the system anyway, the more the merrier [I am wondering whether on the first attempt I didn't lube the o-rings enough causing some of the leaks?]
Is a sniffer more sensitive than a UV dye and a light?
Is the nut between the accumulator and the high-pressure line known to go on hard, or did I mess up and miss align the threads?
Fan and hosing down the condensor: Do you do that to simulate the cooling efficiency at driving speeds?
Rick
TX F-150
Lubing the O-ring is done with straight PAG oil (no UV dye in it)?
Any limit on the amount of lubing, or because PAG oil is in the system anyway, the more the merrier [I am wondering whether on the first attempt I didn't lube the o-rings enough causing some of the leaks?]
Is a sniffer more sensitive than a UV dye and a light?
Is the nut between the accumulator and the high-pressure line known to go on hard, or did I mess up and miss align the threads?
Fan and hosing down the condensor: Do you do that to simulate the cooling efficiency at driving speeds?
Rick
TX F-150
Last edited by TX F-150 4x4; Oct 25, 2006 at 11:55 AM. Reason: grammar
Tuned
Joined: Feb 2003
Posts: 495
Likes: 0
From: Cincinnati, Ohio
I think either cleaning agent will work fine. The flush gun kit sounds like a good way to go.
PAG oil on the o-rings only just enough to coat the whole ring. You can buy the PAG in bottles at most auto parts stores.
Don't know about the sniffer versus the UV dye and light. Both probably work well.
I have had that nut be difficult a number of times and found by lubing the threads with PAG makes it go on easier. If you are reusing a fitting, I think corrosion from the moisture is what makes it tough. You should be able to start and hand tighten that nut before you have to use a wrench.
Fan helps keep the temperature down and there by reducing head pressure. Hosing down the condensor will do the same but with a lot more drop in temperature and pressure, helps to mix the R-134 in the condensor to remove the heat.
Hope this helps.
John
PAG oil on the o-rings only just enough to coat the whole ring. You can buy the PAG in bottles at most auto parts stores.
Don't know about the sniffer versus the UV dye and light. Both probably work well.
I have had that nut be difficult a number of times and found by lubing the threads with PAG makes it go on easier. If you are reusing a fitting, I think corrosion from the moisture is what makes it tough. You should be able to start and hand tighten that nut before you have to use a wrench.
Fan helps keep the temperature down and there by reducing head pressure. Hosing down the condensor will do the same but with a lot more drop in temperature and pressure, helps to mix the R-134 in the condensor to remove the heat.
Hope this helps.
John
Thread Starter
|
Freshman User
Joined: Oct 2006
Posts: 37
Likes: 0
Conversion Techniques
Thank you very much for all the excellent info.
All the parts are in, picking them up tomorrow noon. I hope by Sunday to post favorable results on the conversion.
Rick
TX F-150
All the parts are in, picking them up tomorrow noon. I hope by Sunday to post favorable results on the conversion.
Rick
TX F-150
Thread Starter
|
Freshman User
Joined: Oct 2006
Posts: 37
Likes: 0
Eureka! AC is coooold again, brrr
Sorry I'm late with the results, away at work.
Anyway, I replaced, under warranty, the compressor, accumulator, liquid line, orifice tube, high pressure line. Upon suggestion from "jtmerritt" I also replaced the condensor.
The evaporator core was cleaned with a compressed-air flush-gun kit (from Napa parts) and 1-qt. of cleaning solution. To make sure no residue was left in the core (from the solution) I did a secondary flush with de-natured alcohol (my indie shop uses that one).
When lubing o-rings and replacing lost oil I recommend using oil w/o dye. You will inevitably spill some of it, and it could throw off your post-installation leak test. Also lubing the threaded fittings with a bit of oil, helps; especially the big 1-1/4" nut from the accumulator to the high-pressure line.
Added R-134a conversion fittings. Don't forget to remove the Schraeder valve from the Lo-side port. Parts for this year truck are both R-12 & R-134a capable, but must be converted via a fitting kit. The Lo-side has a new valve (replacing the one on the accumulator); the Hi-side is just a pass-through fitting.
Make sure the Hi-side fitting is screwed all the way down (w/o stripping it). A single turn of the fitting causes it to rise sufficiently on the thread to prevent the HI-side pressure guage from receiving an accurate high-side reading.
Vacuumed the system to 30", let it sit for ~45 minutes.
Do a leak test before recharging the system. 80% rule on refilling worked for me, remember to make allowances for refrigerant used during leak test.
When recharging bridge the clutch cycle switch with a wire, so it will run the compressor continously.
When finished recharging, let the system stabilize and test the pressures.
First pressure reading:
~80F (TWC) with ~90F cabin temp
Lo 34
Hi 235
Vent 48-50F
Second pressure reading:
~52F outside, with 70F cabin temp
Lo 26-43
Hi 130-70
Vent 40F
Compressor ON-OFF
Ford specifies cabin temp for its pressure and vent discharge tables to be accurate, hence the second reading.
Hi-side conversion fittings are pass-through type for the '91 F-150. A loose fitting will prevent the center-pin in the high-side hose of your guage set from depressing the valve in your high side port. Result: vastly lower Hi-side reading, which could lead to misdiagnosis and unnecessary repairs $$$$.
Thanks to jtmerritt, MazdaRangerGuyinSTL, and projectSHO89 for all your help and advice.
Parts and loaner tools from the local AZ store.
TX F-150 4x4
p.s.: I hope, mentioning what stores I got my parts/tools from is OK?
Anyway, I replaced, under warranty, the compressor, accumulator, liquid line, orifice tube, high pressure line. Upon suggestion from "jtmerritt" I also replaced the condensor.
The evaporator core was cleaned with a compressed-air flush-gun kit (from Napa parts) and 1-qt. of cleaning solution. To make sure no residue was left in the core (from the solution) I did a secondary flush with de-natured alcohol (my indie shop uses that one).
When lubing o-rings and replacing lost oil I recommend using oil w/o dye. You will inevitably spill some of it, and it could throw off your post-installation leak test. Also lubing the threaded fittings with a bit of oil, helps; especially the big 1-1/4" nut from the accumulator to the high-pressure line.
Added R-134a conversion fittings. Don't forget to remove the Schraeder valve from the Lo-side port. Parts for this year truck are both R-12 & R-134a capable, but must be converted via a fitting kit. The Lo-side has a new valve (replacing the one on the accumulator); the Hi-side is just a pass-through fitting.
Make sure the Hi-side fitting is screwed all the way down (w/o stripping it). A single turn of the fitting causes it to rise sufficiently on the thread to prevent the HI-side pressure guage from receiving an accurate high-side reading.
Vacuumed the system to 30", let it sit for ~45 minutes.
Do a leak test before recharging the system. 80% rule on refilling worked for me, remember to make allowances for refrigerant used during leak test.
When recharging bridge the clutch cycle switch with a wire, so it will run the compressor continously.
When finished recharging, let the system stabilize and test the pressures.
First pressure reading:
~80F (TWC) with ~90F cabin temp
Lo 34
Hi 235
Vent 48-50F
Second pressure reading:
~52F outside, with 70F cabin temp
Lo 26-43
Hi 130-70
Vent 40F
Compressor ON-OFF
Ford specifies cabin temp for its pressure and vent discharge tables to be accurate, hence the second reading.
Hi-side conversion fittings are pass-through type for the '91 F-150. A loose fitting will prevent the center-pin in the high-side hose of your guage set from depressing the valve in your high side port. Result: vastly lower Hi-side reading, which could lead to misdiagnosis and unnecessary repairs $$$$.
Thanks to jtmerritt, MazdaRangerGuyinSTL, and projectSHO89 for all your help and advice.
Parts and loaner tools from the local AZ store.
TX F-150 4x4
p.s.: I hope, mentioning what stores I got my parts/tools from is OK?
Thread
Thread Starter
Forum
Replies
Last Post
kontoboy
Audio & Video Systems, Navigation, Satellite Radio & Mobile Electronics
9
Sep 12, 2010 10:58 PM
