Ok, I have a 1988 F-150, with a 302, did the converting thing to R134 about 15yrs ago, and on my third A/C compresser, truck has 445,000 miles on it. The truck cools ok at any speed but idle, I have heard that a 1994, or 1995, came with r134 and work much better. My question, how hard would be to put a newer condencer on my old truck, don't want to get rid of her, she has been around longer than 3 wives and 6 girl-freinds, just kidding, but need more cooling, thanks.


John

 

I am not sure you would even need a new condenser....just a different expansion valve...the oil, the compressor everything is cross compatible....go to a web site... ACKits do t com
I did this change on my 94 acura and it is FREEZING cold with just the expansion valve change and charge of r134....and you only need about 80% of R134 than you did of r12.....so if you used 30ozs of r12, you only need 24 ozs of R134.

Good luck!

 

I have a orfice tube, and when it was done the first time it was done by a A/C shop, that I know is a good one.

 

If your AC system has the remains of 3 (4?) compressors floating around in it, you really should consider flushing the system, replacing the orifice, and replacing the accumulator. That would make a huge difference if it wasn't done after each compressor failure.
Replacing the condenser with a newer Parallel Flow type is doable and a good idea, but requires hose modifications. It may not be necessary as long as the rest of the system is up to par.

Knowing the Low and High side pressures at Idle and 1500 RPM would help immensely to diagnose your problem. Without them everything is just a guess.

Idle/low speed is where R134a conversions have the most problems. R12 condensers are not as efficient as R134a condensers and airflow at idle is the lowest. It's not a good combination. If you have a marginal cooling system, bad fan clutch, missing fan shroud, etc. it can really compound the issue.

The first thing you need to do is replace the old (original?) fan clutch with a new Motorcraft or Hayden HD unit. (No "chain store" cheapies) This will give your system a fighting chance and may even be the solution to your current issue. Then diagnose from there.

Edit: lvmilkman is certainly on the right track, he's just not familiar with the system in you truck. I'll add +10 to his recommendation of www.ackits.com. They are one of my preferred suppliers of AC parts. They also sponsor what I believe is the best Automotive AC discussion forum on the Internet: www.autoacforum.com
The Forum is very DIY oriented and there are a number of AC "professionals" who contribute and offer advice. Check it out.

 

Thanks 101, the condenser was changed on the first compresser, and flush on the others, the orifice tube and dryer was changed the second and third times, new Ford fan clutch last fall.

ps; also the last compressor was a Ford, new one.

 

Was told to buy another fan clutch on another forum, so I did, heavy duty Ford, did not make much difference, here is my info:

ambient temp. 94

static low 85
high 85
Idle low 45
high250
1500 rpm low34
high 300
Mist low25-32
high 165-190
Middle vent Idle 55 to 60
55mph 42 to 48
condenser clean so is radiator.

 

Hmm, those numbers are indicate classic signs of restricted airflow over the condenser. (poor heat transfer).
Have you looked between the radiator and condenser, that's where most debris and gook winds up.
Is the correct fan shroud in place and intact?
Does the fan sit about half in and half out of the shroud when viewed from the side?
Are there any missing air deflectors under he bumper or between the grille and condenser?

What style of condenser is on your truck? Is there a large tube at each end with tubes going across, much like a radiator? If so, some of the tubes could be blocked with debris.

 

How about an electric fan on the front side of the condenser to move more air?

 

I just put a pusher fan on the front of condenser, ppl on the other fourm thinks I have air in system, off today, going to have it evacuated, and rechargered, let yall know what happens then.

 

A new condenser is needed. It is clogged with compressor debris.

 

Thanks for reading, got it going pretty good, had a friend evacuate it, changed drier, orifice tube to a orange one, then flushed out the evap. and condenser, got me a new vacuum pump, my old one used air, in witch my little air compressor could not keep up, so I got a 2.5 cfm from harbor freight, worked good.