T1N AC, why does it struggle at temps above 90?

[Coast2Coast]

It hard to tell if its even working. Usually around 80-85 you can definitely feel cool air. Has anyone else experienced weak ac in their t1n sprinter? Is there a solution for this? Mine is a 140 cargo van with the divider and tinted glass which helps a little to reduce heat in summer. I keep the door shut so the ac essentially just has to cool off the front. At 100 degrees it is miserable. My freon was just recharged 2 months ago.

[autostaretx]

Cabin air filter?
Cleaned radiator internal grille?
AC compressor not slipping on its belt?

--dick

[Coast2Coast]

Belt seems fine but possibly.. the cabin filter is new

[skydiver007]

Ok I am by no means an expert but here is what I have found and my solution.

My 05 had terrible AC operation at higher temps and it hardly felt like it was working. I hooked up an AC recharger system and fed it more coolant.

This made it worse. My 05 only requires 1.90 lbs of freon. The higher the temp the more pressure in the system. I had overcharged the system. The AC pump will not come on if the pressure is too high. Time to bleed off some freon.

I would recommend you take yours to a technician who knows Sprinters but all I done was drain mine all the way down and then only fill it to where it was in the lowest part of green for the outside temp. If you can measure the freon, only put in what the plate under the hood says.

You should also test it when it is very hot outside to see what the pressure is. THE PRESSURE GOES UP WITH TEMPERATURE. It will also go up if you have low or no air flowing over the coil.

As has been mentioned on here many times, the Sprinters have a cabin air filter. Mine was clogged to no end and has been removed for the time being and on a 2 setting on the dash fan it will blow you out of the van.

Yesterday the temp here reached 105 and I was driving bak from Charlotte NC to Wake Forest and I had no AC for 100 miles. I knew there was freon in the system. Stopped and checked pressure. it was around 70psi at rest. This is way to high for the pump to even come on. I released some more pressure and came down to around 30 psi and she will now freeze you out. The hotter the temps, the more pressure the system will see.

If you have too much freon in the system, the pump will not come on.

[Boater]

As Skydiver007 says it is really important to get the right amount of refrigerant in the AC system, the correct amount should be marked on a plate under the bonnet. There is no way to measure the amount in the system, other then to vacuum purge the system and weigh the gas taken out. A lot of the chain garages in the UK don't bother to purge the system, they just stick in the full charge, giving the symptoms described. To purge properly the system is supposed to be held under vacuum for an hour or so - the chain garages only spend about 30 minutes from start to finish.

I found a local garage that does a full purge, leak test and then re-gasses the system, the result was much better than when I used a while you wait service, and I will be going to them again soon (car doesn't hold it's gas very well, but leak is not traceable).

You shouldn't need a garage that knows sprinters, but make sure you find one that knows AC and talk to them about the diagnostic methods they use. If they are not going to purge the system first and hold it under vacuum (I think it needs an hour but look it up to be sure) before leak testing and refilling, look elsewhere. The garage I use for my car AC (my sprinter doesn't have AC) is a Ford dealership but the car is a Vauxhall (GM).

Jim

[Dougflas]

The amount of time that the system is vacuumed means nothing. What you should do is apply the vacuum and measure the micron level. It needs to be at 500 microns or less before R134 is introduced into the system. To get to that level, it could take 30 minutes or it could take 3 hours depending upon the condition of the drier and oil.

If you're experiencing poor cooling, ascertain that the electric fan is operating. It should cycle under normal conditions.

[autostaretx]

In another thread, people are finding that their AC condensor fans are wired backwards... so the fan behind the radiator is fighting the normal airflow direction.
That has to affect condensor/AC efficiency.

The test is to determine which way the fan is spinning when the AC turns it on (a suggested method is to probe it with a nylon cable tie poked in from the front)
The fix (if it's spinning the wrong way) is to pull the pins from the motor connector and swap them (the pins are held in by side-of-pin locking tangs... these can be gently pushed in and the pin extracted out the bark by pulling on its wire.

--dick

[pyramidhvacr]

Sucking out door air at 100% plus cabin air filter get dirty faster this way. If driving dirt road OMG 1 filter a month. Pull air from over the hot motor in the hood. easy fix 5 min. filter indoor air now. http://youtu.be/mohdU_lgyNw

[hulagun]

Great thread!
And I'm about to order these part$$ to get my AC back in action (the hose blew Labor Day weekend).

- two compressor hoses
- compressor (the original compressor's clutch squeaks at idle)
- drier

Anything else I need to replace while I am in there? Thanks for any advice.

My plan is to locate a top notch local (San Francisco bay area) auto AC specialist to have them handle the R134 recharge part of the job.