a/c no go Sometimes

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Jul 25, 2005 | 05:01 PM

whistling69deuce

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a/c no go Sometimes

in my 91 f150 i have the trusty 351 and the untrusty e4od. it has been hotter than the hammers of hell around here and i really would like to have working a/c. when it is working it blows ice cold air that sometimes has steam coming from the vents. then others it is justbowing hot air. i have noticed it is a rpm thing. with low rpm's the air cuts to hot. if you hit the od off button to make the engine rev higher than it goes cold again. is this just a sign of lo freon levels or do i have to dig deeper into the fix like a a/c clutch or even compressor??

Jul 28, 2005 | 07:59 PM

whistling69deuce

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would it be worth changing over to a r134a freon rather than the factory r12? i might just do that to see what happens.

Jul 28, 2005 | 08:16 PM

jamiesan

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From: pennsylvania

Well, how's your belt? low RPM accessory woes are often from a loose belt.Which may be because the belt has stretched or... tensioner pulley is tired. After checking these be sure your electric clutch on the ac compressor is functioning properly. Since you still have R 12 ( which you can't do much with as an amature in my state ..PA) I don't know if there's a refill/repair kit or not. The 134R has a kit that comes with a pressure gague , refridgerant, & stop leak. But if you can still get cold air I wouldn't think that you have a leak, as once the stuffs gone...it's gone.

Jul 28, 2005 | 11:16 PM

rshad

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From: Delaware

Check the gap on your compressor clutch. This sounds like a problem I had with my 97 F-150. It did not work at higher RPM's because it would not grab. If it's like mine it will have a 8mm bolt in the middle of the clutch. take out this bolt, (you do NOT have to remove the drive belt) slide off the clutch face and remove one of the spacers that goes in the clutch right under were the bolt goes. You might have more then one spacer. If you don't (like mine) take out the one and make a spacer out of a washer. I sanded down a washer to get the right thickness and it worked great. The gap on mine is supposed to be between 0.018 and 0.033 in. After I put in the home made spacer I now have a gap of around 0.023 in.

Good Luck,

Ron

Jul 29, 2005 | 07:42 AM

95X15

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From: SC lowcountry

The 88 manual for Ford FS-6 compressor and clutch says the gap is to be 0.021 - 0.036" between pulley and hub.
Sound like you are low on Freon if it is freezing up. Find someone with gauges, license for R-12 and check pressures for the conditions you have at the time. Lots of possibilities.
Best to go with R134 in long run.

Aug 3, 2005 | 10:44 AM

jakeash

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my 92 f150 had a bad vac switch that controled the compressor

Aug 3, 2005 | 10:41 PM

handyman43358

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From: West Mansfield, Ohio

At a low RPM is your compressor clutch turning also? Just because the pulley that the belt is on is turning doesnt mean that the clutch is engaged and the pump is working. Make sure that everything is moving. At WOT I believe that the clutch is supposed to let up and make the compressor stop turning b/c at WOT you obviously need the highest amount of horsepower that you can get out of that engine. I'd grab the throttle linkage and slam er over to WOT for a slight second and see if the pump disengages (just to see if everything is working)