The Dakota is currently our only vehicle my pregnant wife can drive, and the AC decided to crap out. I was in the driveway today with 125 degree heat index trying to find the leak, but not having any luck. It did sound like the high press port was leaking a few days ago. I replaced the caps and recharged then (with a shot of dye), but its leaked again. Today I replaced the high press port schrader valve, but the AC is still not holding vacuum very well. It drops from ~25 down to 15-20 in maybe 5-10 minutes, then tapers off but still loses. I can't seem to find any dye residue leaking out. I have my gauges hooked up while its under vacuum so I don't think the leak is related to the service ports.

Is there an easy way to put eyeballs on the evaporator to see if any dye shows up there?

Any common problem areas for leaky AC on these trucks?

Thanks
Keith

 

Nothing that normally wears except for O-rings and seals. Yes use the Dye and the UV light at night. No way to see within the evap core without tearing all apart.

 

Ok.. I just picked up a seal kit and have an accumulator on order. I pulled a vacuum of abt 25 on Friday night and it had dropped to 15 as of this morning, about 36 hours later. Where ever it is, it's a slow leak. It was dark when I did the dye check, and I couldn't see anything.

Anyone tried a variable orifice tube? We have a lot of stop-n-go traffic around here. Based on the claims I've seen, it should help in this situation.

Keith

 

Did you use the UV dye with a UV light?

 

yep, even used the special glasses.

Keith

 

Went throught same thing with mine earlier this summer. Mine turned out to be the evaporator. No easy way to get to it. You have to pull the whole ventilation system out from under the dash. On the plus side I noticed the leak I had on the heater core as well while I had it all out and replaced that too.

 

Yesterday I replaced all of the o-rings and the two flat seals on top of the compressor. I did not go into the passenger compartment, so if there are seals in there, they didnt get replaced. The accumulator I bought wasn't fitting right. I compared to the old one and the pipe going towards the firewall was off by maybe 25 degrees. I was about to take it back, when I remembered they had to special order that one. So, put it in the vise and bent it. Also installed a variable orifice tube. Pulled a vacuum of abt 25 this afternoon. Two hours later, it hadn't budged - a promising improvement. If its still holding tomorrow, refrigerant is going back in.

Keith

 

The only way to check the evaporator that I know of without pulling it is to partially charge the system and then stick a sniffer into the vents and turn the blower on and see if it gets set of with leaking refrigerant.
Sounds like you might have fixed the problem though.