My 92 f150 4.9 suddenly has very weak air conditioning. It just doesnt get very cold unless im doing 70 down the highway. And even then it still isnt as good as it usually is. Low side pressure is good (55 psi and its about 90* outside) condenser and evaporator are very clean. No blocks in the return and the evap is making water. I believe the orifice filter/tube is clogged. Where is the orifice located on this truck? Do i need a special tool to remove it? Thanks

 

Just an update, the compressor started making grinding noises intermittently. It grinds for about 30 seconds randomly while driving. Still cooling but weak like i mentioned.

 

Does the compressor cycle on and off a lot? To get to the orifice tube you have to evacuate the system and disconnect the liquid line from the firewall to condensor on passenger side.

Although if your compressor is grinding it would probably be a good idea to replace it and flush/replace your hoses to clean out any debris in your sytem

 

If your compressor is making noise then shut the a/c off and don't use it again til you fix it. If the compressor grenades then you'll have to replace a bunch of other parts when the little bits and pieces get carried downstream.

 

no its not overcycling. I have all the equipment to flush/evacuate the system properly, I service residential and commercial a/c's for a living. I just need the adapter so I can hook up my gauges to the truck. the cars are definitely different than homes and buildings

 

I had that thought but it was so damn hot out I said ***** it and took a chance. I drove the truck 240 miles straight with the air on and it didn't make the noise again and its actually still cooling. the truck is home now so I can leave it until Im ready to correct the problem. thanks for the concern!