A/C Improvement ?
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Freshman User
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A/C Improvement ?
Its that time of year again, my sixth in Alabama and the 100 deg F days have come early this year.
My truck, 1985 F350 dually 6.9 4 speed.
Air con info, Low side 40 psi, high side 260 psi, outside temp 100 F.
The vent temp is 60 F parked 50 F at 55 MPH.
I have no previous owner info or contact, the system has R134a ports and refrigerant. The accumulator is black painted steel and looks old and there is no conversion sticker (shadetree job)
Questions
1 Would a flush, replace accumulator, vac and re-charge help?
2 There is no water shutoff valve in the heater pipes. fitting one would ensure that the heater matrix will stay cold, any benefit?
3 Space looks tight in front of the condenser with not much room for a fan. Has anyone managed to squeeze one (or two) in there?
4 Do the evaporator fins on these trucks collect crud, is it easy to get out and clean? or blow it clean in situ?
5 Have i missed anything?
6 How cold does yours get?
Re the above shadetree comment, I will also be working under a large shady tree but the local a/c shop will remove freon for free after all I do buy my tyres from him.
Thanks
Steve
My truck, 1985 F350 dually 6.9 4 speed.
Air con info, Low side 40 psi, high side 260 psi, outside temp 100 F.
The vent temp is 60 F parked 50 F at 55 MPH.
I have no previous owner info or contact, the system has R134a ports and refrigerant. The accumulator is black painted steel and looks old and there is no conversion sticker (shadetree job)
Questions
1 Would a flush, replace accumulator, vac and re-charge help?
2 There is no water shutoff valve in the heater pipes. fitting one would ensure that the heater matrix will stay cold, any benefit?
3 Space looks tight in front of the condenser with not much room for a fan. Has anyone managed to squeeze one (or two) in there?
4 Do the evaporator fins on these trucks collect crud, is it easy to get out and clean? or blow it clean in situ?
5 Have i missed anything?
6 How cold does yours get?
Re the above shadetree comment, I will also be working under a large shady tree but the local a/c shop will remove freon for free after all I do buy my tyres from him.
Thanks
Steve
Logistics Pro
Joined: Dec 2005
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From: Moro Bay, AR
When these trucks get as many years on them as we like to run, the seals on the doors in the A/C box have disintegrated and are useless. I always install a water valve in the heater hoses, it will drop the vent temps as much as 10*. I did this on my 94 F250 yesterday and got a 8* drop just from this mod. The valve I used is for a Ford Ranger, I think a 97 model, Four Season part #74809, I think it was around $30. Install this valve in the heater hoses and "T" the vacuum line into the line running to the fresh air door control located under the hood, right above the blower motor(plastic line is usually white) and it will work automatically.
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Joined: Apr 2005
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From: NC
Steve
your pressures are close for a good conversion. r12 to 134a conversions most of the time dont work so good. bypassing the heater core will help some. hook your gauges back up and spray the condenser with a garden house. if the pressures drop like a rock, and the vent temps should drop too, if your fan cluch is more than 3 years old i would replace it, also the oem condensers dont work too good with 134a, replacing it with a parallel flow condenser will help you out.
Unobvs,
there are no factory pressure readings for ac systems since the pressures will change with air temp. all ac systems are filled by weight, for 1985 its 48oz of r12 86 to 90 is 52oz of r12........ for 134a conversions are usaly 20 to 30% less than r12
your pressures are close for a good conversion. r12 to 134a conversions most of the time dont work so good. bypassing the heater core will help some. hook your gauges back up and spray the condenser with a garden house. if the pressures drop like a rock, and the vent temps should drop too, if your fan cluch is more than 3 years old i would replace it, also the oem condensers dont work too good with 134a, replacing it with a parallel flow condenser will help you out.
Unobvs,
there are no factory pressure readings for ac systems since the pressures will change with air temp. all ac systems are filled by weight, for 1985 its 48oz of r12 86 to 90 is 52oz of r12........ for 134a conversions are usaly 20 to 30% less than r12
New User
Joined: Apr 2007
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From: Bay Area CA
Thanks Diesel250. I charged the sytsem with three pounds yesterday (after pulling a vacuum for 30+ minutes) and was cooled by the results but by no means frozen! Is there a picture-laden post that describes fully the "water valve" trick described above?
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Thanks guys, but please keep em comming. I will report back after doing the water valve addition this weekend, just had a look for the pneumatic motor above the heater motor, thanks for that tip i was going to fit a manual valve but the ranger valve is a slick idea.
Many thanks, keep em comming guys I am sure I am not the only one who wants max cooling performance this summer.
Steve
Many thanks, keep em comming guys I am sure I am not the only one who wants max cooling performance this summer.
Steve
Logistics Pro
Joined: Dec 2005
Posts: 4,644
Likes: 55
From: Moro Bay, AR
Originally Posted by unobvs
Thanks Diesel250. I charged the sytsem with three pounds yesterday (after pulling a vacuum for 30+ minutes) and was cooled by the results but by no means frozen! Is there a picture-laden post that describes fully the "water valve" trick described above?
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New User
Joined: Apr 2007
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Outside air temperature and even humidity play a big role in A/C performance. Steve, your numbers look good. Air duct temperatures and high and low side pressures should be read with A/C on MAX, high blower speed and engine at 2000 RPM.
Anyone adding their own refrigerant, please remember that the cans are 12 ounces, not one pound. So if your system calls for 3 pounds, you will need 4 cans.
The evaporator can get covered with crud and may need to be cleaned eventually. You would know it's time by a noticable decrease in air flow volume from the vents.
Hope this helps.
Ron
Anyone adding their own refrigerant, please remember that the cans are 12 ounces, not one pound. So if your system calls for 3 pounds, you will need 4 cans.
The evaporator can get covered with crud and may need to be cleaned eventually. You would know it's time by a noticable decrease in air flow volume from the vents.
Hope this helps.
Ron
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Thanks for the pictures, I fitted the valve this evening and got the vac lines working.
But the line's going to the heater matrix are still very hot even when the system is set to max?
Could I have a faulty valve? It did not seem to seal when i blew through it while holding the actuating arm closed.
Any ideas?
Thanks
Steve
But the line's going to the heater matrix are still very hot even when the system is set to max?
Could I have a faulty valve? It did not seem to seal when i blew through it while holding the actuating arm closed.
Any ideas?
Thanks
Steve
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Freshman User
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The ford ranger does not cut off al the water flow th the heater. I have bypassed the heater for now and am getting 40 F on max and 45 on norm at mph on a 95 F day.
Plan to replace fan cluch, and maybe fit a pair of two port heater valves one in each line if that fails it will have to be manual valves.
Is it risky shutting off the water in the heater line? many cars do this.
thanks
Steve
Plan to replace fan cluch, and maybe fit a pair of two port heater valves one in each line if that fails it will have to be manual valves.
Is it risky shutting off the water in the heater line? many cars do this.
thanks
Steve
Junior User
Joined: Jun 2005
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Hooking up the hot water bypass works great and the part is available off both Ranger and Explorer. For those T-ing into the outside air vacume motar keep in mind that this only applies vacume (bypasses water flow) when the selector is in the OFF or MAX AC position. I Tee mine into a vacume port in the summer and disconnect it in the Fall. Might try to find/hookup vacume switch when I get time.
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Bummed Out
Not a good day for my truck.
The alternator belt had been jumping in its pulleys so I bought all four belts this all went well even with the stripped alternator thread (easy fix) BUT upon setting the power steering belt I could hear a hissing noise comming from the condenser! Come to think of it the pipe was at a funny angle before i started work.
Oh "BOTHER" says I in my native London accent, I need a ******* condensor!!!!
More questions.
Does the condensor come out from the grill size or is it a radiator out job?
Is a parallel condensor that much more expensive or even required?
Just when I had 40F air at the vents
Bummed out but always greatful for your help
Steve
The alternator belt had been jumping in its pulleys so I bought all four belts this all went well even with the stripped alternator thread (easy fix) BUT upon setting the power steering belt I could hear a hissing noise comming from the condenser! Come to think of it the pipe was at a funny angle before i started work.
Oh "BOTHER" says I in my native London accent, I need a ******* condensor!!!!
More questions.
Does the condensor come out from the grill size or is it a radiator out job?
Is a parallel condensor that much more expensive or even required?
Just when I had 40F air at the vents
Bummed out but always greatful for your help
Steve