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RV-2 AC clutch locks up after getting hot

Posted By: AKcharger

RV-2 AC clutch locks up after getting hot - 06/24/22 01:52 AM

I had the ENTIRE AC system refurbished...EVERYTHING. System runs fine, pressures about 30 PSI low side and 185 high side. after about 15 minutes f I drive it the clutch starts to lock up (belts NOT slipping) and pressures bounce around 85 Low side and 150 high side. has anyone seen this and have an idea what's wrong??
https://youtu.be/OwhaJn5edt8
Posted By: NITROUSN

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 02:21 AM

I don't think that clutch is working correct. It is not staying engaged and thats why the low pressure is going up.
Posted By: PhillyRag

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 03:04 AM

How does the pulley portion seem when you spin it, without belts on it?
Posted By: GMP440

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 03:13 AM

Yes, I have seen and experienced this a couple months ago. The clutch plate is not gripping the pulley. Had this happen a few months ago on a Denso compressor on my 91 Ford Crown Vic. The clutch plate was not gripping the face of the pulley and was slipping making that same noise. I fixed that by getting a clutch and pulley from another denso compressor that was on an 89 Lincoln Town Car that was in a salvage yard. Everything has been good ever since.
To rule out the compressor, turn the engine off , turn the key on for power to the accessories, then, with a gloved hand just turn the clutch, rotating the compressor. If it turns freely, the compressor is not locked. Then only thing left is the clutch plate losing it's grip.
Also, as someone stated remove the belt and spin the pulley to make sure that is rolling free.
Posted By: moparx

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 02:54 PM

isn't there a procedure to break in a new clutch, once one replaces it ? shruggy
beer
Posted By: stumpy

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 03:19 PM

Not that I've ever heard of but I don't know everything. whistling
Posted By: 440lebaron

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 03:28 PM

as i recall the clutch has a shim adjustment, small washer on shaft 3/8 5/16 dia??
Posted By: 4406bbl

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 06:01 PM

I would say it is overcharged and burnt the clutch. Is it 134 or r-12 freon? There is a break in procedure for those, switch on off 10 times when it is a new clutch, I think that is a joke, a way out of warranties for the reman companies. In the 80s clutches were smoking all the time, that was their way out of warranties, what was actually happening on some mopars is the a/c switch could not pass enough current to hold the clutch reliably and they would smoke it. It could also be the coil behind the pulley is weak. When you change your clutch install a jumper wire straight to the battery and run it that way until charged and cooling, then try the original wiring, if it squeeks on the original you know your dash switch is bad. Anyway some cars were real bad about it, a 20 amp dual pole toggle switch, a fuse and some wire is your friend, I don't trust 50 year old dash switches if the clutch is smoking.
Posted By: NITROUSN

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 07:23 PM

Originally Posted by 4406bbl
I would say it is overcharged and burnt the clutch. Is it 134 or r-12 freon? There is a break in procedure for those, switch on off 10 times when it is a new clutch, I think that is a joke, a way out of warranties for the reman companies. In the 80s clutches were smoking all the time, that was their way out of warranties, what was actually happening on some mopars is the a/c switch could not pass enough current to hold the clutch reliably and they would smoke it. It could also be the coil behind the pulley is weak. When you change your clutch install a jumper wire straight to the battery and run it that way until charged and cooling, then try the original wiring, if it squeeks on the original you know your dash switch is bad. Anyway some cars were real bad about it, a 20 amp dual pole toggle switch, a fuse and some wire is your friend, I don't trust 50 year old dash switches if the clutch is smoking.


His pressure readings would show if it was overcharged. Which they do not. I agree he could try 12 volts direct to the clutch to eliminate all the rest of the electrical system. For what it is worth I have never seem much clutch failures as the old rv2 was fairly reliable.
Posted By: crackedback

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 08:44 PM

Originally Posted by 4406bbl
I would say it is overcharged and burnt the clutch. Is it 134 or r-12 freon? There is a break in procedure for those, switch on off 10 times when it is a new clutch, I think that is a joke, a way out of warranties for the reman companies. In the 80s clutches were smoking all the time, that was their way out of warranties, what was actually happening on some mopars is the a/c switch could not pass enough current to hold the clutch reliably and they would smoke it. It could also be the coil behind the pulley is weak. When you change your clutch install a jumper wire straight to the battery and run it that way until charged and cooling, then try the original wiring, if it squeeks on the original you know your dash switch is bad. Anyway some cars were real bad about it, a 20 amp dual pole toggle switch, a fuse and some wire is your friend, I don't trust 50 year old dash switches if the clutch is smoking.


Or do something like this...

[Linked Image]
Posted By: GMP440

Re: RV-2 AC clutch locks up after getting hot - 06/24/22 08:48 PM

Originally Posted by AKcharger
I had the ENTIRE AC system refurbished...EVERYTHING. System runs fine, pressures about 30 PSI low side and 185 high side. after about 15 minutes f I drive it the clutch starts to lock up (belts NOT slipping) and pressures bounce around 85 Low side and 150 high side. has anyone seen this and have an idea what's wrong??
https://youtu.be/OwhaJn5edt8


When you've done all the checks and the clutch is still slipping; take the clutch off and show pics of the clutch face and the pulley face to see the wear on those parts.
Posted By: 4406bbl

Re: RV-2 AC clutch locks up after getting hot - 06/25/22 02:22 AM

Originally Posted by NITROUSN
Originally Posted by 4406bbl
I would say it is overcharged and burnt the clutch. Is it 134 or r-12 freon? There is a break in procedure for those, switch on off 10 times when it is a new clutch, I think that is a joke, a way out of warranties for the reman companies. In the 80s clutches were smoking all the time, that was their way out of warranties, what was actually happening on some mopars is the a/c switch could not pass enough current to hold the clutch reliably and they would smoke it. It could also be the coil behind the pulley is weak. When you change your clutch install a jumper wire straight to the battery and run it that way until charged and cooling, then try the original wiring, if it squeeks on the original you know your dash switch is bad. Anyway some cars were real bad about it, a 20 amp dual pole toggle switch, a fuse and some wire is your friend, I don't trust 50 year old dash switches if the clutch is smoking.


His pressure readings would show if it was overcharged. Which they do not. I agree he could try 12 volts direct to the clutch to eliminate all the rest of the electrical system. For what it is worth I have never seem much clutch failures as the old rv2 was fairly reliable.


His pressure readings at idle do not show overcharge, what are they when the engine is at 2000-3000 rpm? What freon, if 134 it should bubble at the sight glass
I have seen rv-2 systems with bad expansion or epr valves pull the low side into a vacuum... and smoke the clutch.
Posted By: NITROUSN

Re: RV-2 AC clutch locks up after getting hot - 06/25/22 01:11 PM

Originally Posted by 4406bbl
Originally Posted by NITROUSN
Originally Posted by 4406bbl
I would say it is overcharged and burnt the clutch. Is it 134 or r-12 freon? There is a break in procedure for those, switch on off 10 times when it is a new clutch, I think that is a joke, a way out of warranties for the reman companies. In the 80s clutches were smoking all the time, that was their way out of warranties, what was actually happening on some mopars is the a/c switch could not pass enough current to hold the clutch reliably and they would smoke it. It could also be the coil behind the pulley is weak. When you change your clutch install a jumper wire straight to the battery and run it that way until charged and cooling, then try the original wiring, if it squeeks on the original you know your dash switch is bad. Anyway some cars were real bad about it, a 20 amp dual pole toggle switch, a fuse and some wire is your friend, I don't trust 50 year old dash switches if the clutch is smoking.


His pressure readings would show if it was overcharged. Which they do not. I agree he could try 12 volts direct to the clutch to eliminate all the rest of the electrical system. For what it is worth I have never seem much clutch failures as the old rv2 was fairly reliable.


His pressure readings at idle do not show overcharge, what are they when the engine is at 2000-3000 rpm? What freon, if 134 it should bubble at the sight glass
I have seen rv-2 systems with bad expansion or epr valves pull the low side into a vacuum... and smoke the clutch.


Wrong vacuum will never hurt a clutch. High pressures will cause strain and possible failures. Never, never, vacuum.
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