Fuso inadequate AC system fixed

[SkiFreak]

So Kerry... do you think that the valve you installed to bypass the cab heater has had any beneficial effect?

[kerry]

It's too early to tell. I need to go on a long drive on a hot day to know. I just read a thread on another forum where a guy claims that his condenser in a Mercedes 126 which had been converted to R134 was too small to re-liquify the refrigerant above 95 degrees. Below 95 degrees is worked ok but when ambient reached 95 degrees he gained 10 degrees of temperature at the AC vents. Our condensers are not huge. However an inadequate condenser would not account for my experience of inadequate cooling at highway speeds and adequate cooling around town at low speeds. Someone suggested to me that low refrigerant may exhibit these symptoms. I sure would like to know what temperatures other people are experiencing at varying speeds to know if my truck is an anomaly or not.

[kerry]

Here's an interesting post where someone claims they have a problem with the system cycling off:

http://www.justanswer.com/mitsubishi...-mechanic.html

[kerry]

I just heard from Michel. He says the control valves improved the cooling a lot.

[kerry]

OK here's an update with some not so good news and some good news. We're driving east from Denver across Colorado and Kansas. Air temps just over 90 degrees. Coolant shut off valves made a slight difference. Maybe a degree or two cooler at the vents but still 60+ degrees at the vents at speed. Not cool. Stopped at a picnic site for lunch and let the truck idle. Vent temps in low 40's. Soon as we got back on the road, vent temps went up to mid-60's. So I was trying to imagine what might be causing the problems at speed if it wasn't hot coolant flowing thru the heater core. I speculated that maybe the condenser wasn't getting adequate air flow at speed. We stopped in St Francis for fuel and I looked at the condenser. Mine has a rubber flap that extends down in front of the condenser just behind the bumper. I suppose it's there to protect the condenser from road debris but I thought it might be disturbing the air flow at speed so I bent it up and tucked it behind the bumper and pulled out on the highway. Presto, problem solved. Vent temps now at 43-45 degrees at speed! In fact, it was freezing us out. Had to turn it down. I think what is happening is that the rubber flap bends backwards at speed and directs the air under the condensor so it doesn't work. At low speeds it hangs straighter and the fan can suck air up thru the condenser. Anyway, it looks like my problem is solved. I'm assuming that rubber flap is OE. If so, it's a stupid design. So if your AC is not cooling well at speed, get that rubber flap out of the way and see if it improves.

[SkiFreak]

I'm thinking that a nice little picture that demonstrates the problem you have described/resolved would be good.

[kerry]

My camera batteries are dead In these pictures I had, you can see the flap hanging down under the front license plate.

[FG Surfari]

To note, I removed the same rubber condenser surround on my FG when I fitted the larger tires to the truck a few months ago.
As such, you are correct in your find, as the AC in my rig is much colder now.

[DontPanic42]

Since the rubber flap appears to be for protecting the condenser from damage by rocks and other debris, how practical do you think replacing it with a mesh one similar to the wire screen around the transmission cooler? Sounds like a winter project for me.

[kerry]

My wife suggested mesh too. I'm not convinced the protection is really necessary. What do other think? I suspect mesh might even disturb the air flow into the condenser. I've got a standard transmission so I'm not sure what the transmission wire mesh looks like. I think swapping out the rubber for something else would be pretty easy. I think it's just pop riveted to the bracket.