Clutch not engaging, but there is lots more

Jag987 on Wed July 31, 2013 9:10 PM

Year: 1995
Make: Dodge
Model: Ram 2500 truck
Engine Size: 5.9 DSL
Refrigerant Type: R-134a
Ambient Temp: 85
Pressure Low: 35
Pressure High: 210

Disclaimer: readings and temperature are to my memory, they may be off just a little.

This truck came in just for a recharge. Customer had done something with the turbo and had removed a hose and accumulator for about a month. They were capped off, but unsure of how good and stated no oil had been lost. They only wanted it to be recharged and refused to change accumulator at the time. So I pulled a good long vacuum and it held so I recharged to spec. Vent temp was 40 so I moved on to the next job.

A couple of hours latter I was standing next to this truck again and could HEAR a leak. I opened the hood and quickly determined it was one of the connections going to the evaporator...then the line from the accumulator blew off practically in my hand. Needless to say I found the leak. It was a snap spring type connection that must not have been put back on all the way when my customer re-installed it. I then added 2 ounces of oil and reconnected. it was a bear to get it to snap in so I am quite sure it was not properly installed. Vacuumed again and recharged. Pressures rose back up to about where they were earlier but the vent temp was now 70!!! The ambient temp had risen about 5 degrees to about 90. And then the customer showed up to get the truck and it gets even better. Next the vent temp starts going up and I get really confused until I see the gauges equalize and see that the compressor is not turning.

I shut it off and turned it back on a few times and the clutch does not engage so I climbed underneath with a metal wench to see if the clutch is energized. It sucked the wrench right up to it and as soon as it made contact, the clutch engaged, pressures went back to where they were and vent temp back to about 70. I turned the ac on and off several times and each time to only way it would engage is if I tapped on the clutch. The air gap looked very wide, I did not put a feeler gauge on it (customer standing over me wanting to go) but would guess it was the width of 2-3 business cards.

My questions:

Could the clutch be worn out to the point it is slipping accounting for good pressure, but low refrigerant flow so low cooling?
The parts book show a SD7H15 compressor, does the clutch have shims or should it just be replaced?
How stupid was I for even taking the job without replacing the accumulator under the circumstances?
And would that be the first step to get the temp back down?

Thank you everyone and stay cool!

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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!

mk378 on Wed July 31, 2013 11:43 PM

That is very typical when the gap is too wide. Engages OK when cold, but not after the coil warms up. It's not that it's slipping, but just failing to re-engage after the first time it cycles off.

Jag987 on Thu August 01, 2013 7:32 PM

What about the huge difference in cooling? Once the clutch is engaged it does not cycle and did take a full charge? It makes me upset and frustrated because it will be about a week until I can work on this truck again.

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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!

wptski on Thu August 01, 2013 7:47 PM

Deleted

Edited: Thu August 01, 2013 at 7:50 PM by wptski

Chick on Thu August 29, 2013 7:41 PM

Quote
Originally posted by: Jag987
What about the huge difference in cooling? Once the clutch is engaged it does not cycle and did take a full charge? It makes me upset and frustrated because it will be about a week until I can work on this truck again.

Heat and humidity determine weather it will cycle or not..Adjust the clutch gap, and if it cools, don't fix what isn't broken.. Not sure it that truck has a cycling switch, if it does, then it won't cycle if the pressure stays above 30 - 35psi on the low side.. if it drops below and the comnpressor doesn't cycle, change the cycling switch..Hope this helps..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

Jag987 on Thu August 29, 2013 11:56 PM