89 1500 Drivebelt shaking & Squealing with A/C on

[steelerguy]

Just had my system recharged after replacement of the high & low side shrader valves. It blows ice cold air again but there is a problem after the engine has been running a while & particularly on very hot days (over 105 degrees).

If you look at the drivebelt without the A/C on, everything looks normal. Turn on the A/C & there as noticeable jumping of the belt between the A/C compressor & the lower pulley. The tensioner does not seem able keep up & there is even occaisonal squealing of the belt on accelrating from a dead stop. I have already changed the Tensioner (from Checker) and put on a new Gates Gatorback from Carquest. The jumping looks a little less but the squealing is just as bad.

The belt movement is barely noticeable right after a cold startup. I've never looked at it with the A/C before this problem occurred so I don't have anything to compare it to.

The engine has been running hotter this summer than ever before, sometimes going close to the 3/4 during traffic slowdowns & stops rather than the middle 190 to 210 range it almost always stays at. I do not hear the fan cluth kicking in at start up or when it starts heating up. The thermostat seems to kick in around 190 and you can feel flow in radiator hose to it. Now I'm wondering if the all problems are caused by the overheating. The fan clutch is about 5 years old. My Haynes manual has a checkout of it from what I remember but I think that it is only when the engine is cold.

I'm wondering if I got a bum Tensioner from Checker? Pretty unlikely I would think...but then the new wheel is plastic as opposed to the old hard steel one. I still have the old steel one. Will try swapping the old one out for the weekend and see if it still squeals.

Is my 5-year-old compressor going bad or was there some way that Brakes Plus, who did the A/C work, could have not put enough oil in the system? They only evauated the R-12 freon as far as I know. I have seen lubricant bottles that you can add to your R-12 systems. Anyone tried these? Can they do as much harm as good?

Thanks for your ideas and words of wisdom.

[jveik]

yeah i would make sure the compressor doesn't have bad bearings or bushings or whatever a compressor would spin on. then tighten the belt like none other and try her out

[obxcars]

Originally Posted by steelerguy

Just had my system recharged after replacement of the high & low side shrader valves. It blows ice cold air again but there is a problem after the engine has been running a while & particularly on very hot days (over 105 degrees).

If you look at the drivebelt without the A/C on, everything looks normal. Turn on the A/C & there as noticeable jumping of the belt between the A/C compressor & the lower pulley. The tensioner does not seem able keep up & there is even occaisonal squealing of the belt on accelrating from a dead stop. I have already changed the Tensioner (from Checker) and put on a new Gates Gatorback from Carquest. The jumping looks a little less but the squealing is just as bad.

The belt movement is barely noticeable right after a cold startup. I've never looked at it with the A/C before this problem occurred so I don't have anything to compare it to.

The engine has been running hotter this summer than ever before, sometimes going close to the 3/4 during traffic slowdowns & stops rather than the middle 190 to 210 range it almost always stays at. I do not hear the fan cluth kicking in at start up or when it starts heating up. The thermostat seems to kick in around 190 and you can feel flow in radiator hose to it. Now I'm wondering if the all problems are caused by the overheating. The fan clutch is about 5 years old. My Haynes manual has a checkout of it from what I remember but I think that it is only when the engine is cold.

I'm wondering if I got a bum Tensioner from Checker? Pretty unlikely I would think...but then the new wheel is plastic as opposed to the old hard steel one. I still have the old steel one. Will try swapping the old one out for the weekend and see if it still squeals.

Is my 5-year-old compressor going bad or was there some way that Brakes Plus, who did the A/C work, could have not put enough oil in the system? They only evauated the R-12 freon as far as I know. I have seen lubricant bottles that you can add to your R-12 systems. Anyone tried these? Can they do as much harm as good?

Thanks for your ideas and words of wisdom.

you may have two problems. Is the truck overheating with the a/c off? Check the fan clutch (cold) check that the radiator/condensor/trans cooler are not restricting air flow - dirty. If the compressor is starting to lockup from too little oil in system, the damage is done. If the belt only squeals and jumps with the a/c on its probably the compressor or clutch on compressor. maaabee

[ROBIN LAYTON]

Hi, I would consider that the radiator fan clutch might be the fault . To check it hot ,open the hood with the engine at temp and running then shut the truck off and see if the fan stops turning quickly. It is supposed to. Also it could be the compressor load.

[timssail]

Originally Posted by ROBIN LAYTON

Hi, I would consider that the radiator fan clutch might be the fault . To check it hot ,open the hood with the engine at temp and running then shut the truck off and see if the fan stops turning quickly. It is supposed to. Also it could be the compressor load.

what does a fan clutch sound like when it is starting to fail. Mine I think is the culprit of some weird noises and squeeky belts. How should it behave when cold? any help on this would be great.

[steelerguy]

Originally Posted by steelerguy

Just had my system recharged after replacement of the high & low side shrader valves. It blows ice cold air again but there is a problem after the engine has been running a while & particularly on very hot days (over 105 degrees).

If you look at the drivebelt without the A/C on, everything looks normal. Turn on the A/C & there as noticeable jumping of the belt between the A/C compressor & the lower pulley. The tensioner does not seem able keep up & there is even occaisonal squealing of the belt on accelrating from a dead stop. I have already changed the Tensioner (from Checker) and put on a new Gates Gatorback from Carquest. The jumping looks a little less but the squealing is just as bad.

The belt movement is barely noticeable right after a cold startup. I've never looked at it with the A/C before this problem occurred so I don't have anything to compare it to.

The engine has been running hotter this summer than ever before, sometimes going close to the 3/4 during traffic slowdowns & stops rather than the middle 190 to 210 range it almost always stays at. I do not hear the fan cluth kicking in at start up or when it starts heating up. The thermostat seems to kick in around 190 and you can feel flow in radiator hose to it. Now I'm wondering if the all problems are caused by the overheating. The fan clutch is about 5 years old. My Haynes manual has a checkout of it from what I remember but I think that it is only when the engine is cold.

I'm wondering if I got a bum Tensioner from Checker? Pretty unlikely I would think...but then the new wheel is plastic as opposed to the old hard steel one. I still have the old steel one. Will try swapping the old one out for the weekend and see if it still squeals.

Is my 5-year-old compressor going bad or was there some way that Brakes Plus, who did the A/C work, could have not put enough oil in the system? They only evauated the R-12 freon as far as I know. I have seen lubricant bottles that you can add to your R-12 systems. Anyone tried these? Can they do as much harm as good?

Thanks for your ideas and words of wisdom.

Update: the squealing was caused by the new tensioner from checker. The wheel was plastic rather than metal. I put the old tensioner back on and got a refund.

I still need to change the fan clutch. It has not been as hot lately (September), so I've been blowing it off.

[steelerguy]

Originally Posted by timssail

what does a fan clutch sound like when it is starting to fail. Mine I think is the culprit of some weird noises and squeeky belts. How should it behave when cold? any help on this would be great.

timssail,

The fan clutch is the round unit that has the fan blades bolted to it that are behind the radiator. On most vehicles, it engages on start up and make a roaring noise until it warms up. It is supposed to come on whenever the vehicle heats up again when the thermostat can no longer keep the core temperature down (usually in slow or stalled traffic on hot days). It uses it's own sensors to detect heat. Robin Layton's advice seems more knowledgeable than my experience. There is also a cold check in the Haynes manual, but I don't know accurate it is. I would be surprised if it caused squeaky belts but then I'm surprised at what I learn all of the time.

Goodluck,

[timssail]

Originally Posted by steelerguy

timssail,

The fan clutch is the round unit that has the fan blades bolted to it that are behind the radiator. On most vehicles, it engages on start up and make a roaring noise until it warms up. It is supposed to come on whenever the vehicle heats up again when the thermostat can no longer keep the core temperature down (usually in slow or stalled traffic on hot days). It uses it's own sensors to detect heat. Robin Layton's advice seems more knowledgeable than my experience. There is also a cold check in the Haynes manual, but I don't know accurate it is. I would be surprised if it caused squeaky belts but then I'm surprised at what I learn all of the time.

Goodluck,

I notice that it does not act like my old 1995 305 fan did on startup ( no roar) I guess if the knocking comes back i will replace that too. thanks for the reply, Regards, Tim

[timssail]

Originally Posted by timssail

I notice that it does not act like my old 1995 305 fan did on startup ( no roar) I guess if the knocking comes back i will replace that too. thanks for the reply, Regards, Tim

Now the belt is quiet and no knocking at all, sounds like the day I bought it. That really makes me Nervous. I did use some belt ease on the back side of the belt.

[steelerguy]

Originally Posted by timssail

Now the belt is quiet and no knocking at all, sounds like the day I bought it. That really makes me Nervous. I did use some belt ease on the back side of the belt.

If you even suspect that your belt is worn or don't know its age, spend the $20 to $30 for a new one. I spend the extra for Gate gatorbacks at NAPA or Carquest. If that belt goes and you can't shut it off immediately, your water pump no longer cools your engine & it's a matter of seconds to warp your head. From what I understand, modern belts only squeal when they're about to go bad.

Use a breaker bar to take load off of the tensioner. Doen't have to be super strong. I cut a 3-foot section of PVC. It'll save your knuckles from being crushed by slips. Take my word for it.

[timssail]

Originally Posted by steelerguy

If you even suspect that your belt is worn or don't know its age, spend the $20 to $30 for a new one. I spend the extra for Gate gatorbacks at NAPA or Carquest. If that belt goes and you can't shut it off immediately, your water pump no longer cools your engine & it's a matter of seconds to warp your head. From what I understand, modern belts only squeal when they're about to go bad.

Use a breaker bar to take load off of the tensioner. Doen't have to be super strong. I cut a 3-foot section of PVC. It'll save your knuckles from being crushed by slips. Take my word for it.

I did replace the belt and the old one looks about the same. I put on a NAPA belt, idle pully, and new tensioner, Like I said the belt is quiet and no noise from anything else at this point. I plan to drive to Florida in 2 weeks and I do not want any surprises. The water pump could be on its way out but no sign of any failure. I will let you know. Oh to remove the belt I just use my hands on this engine. Much easier than the 305.