2000 Ford F250 Diesel air cond problems
 

Just started todaynever have had a problem ever--heat/ac/fresh air all work -Air Cond and heat or vent ONLY come out of the DEFROST ducts not the floor or dash vents---checked pump it hums (maybe running but no vacuum is it bad?)checked hoses all seem to be connected under dash by glove box as well as engine compartment no loose hoses-- truck DOES NOT have Electronic air cond it has manual AC is there any ideas any one has?? Thanx FED 387

Re: 2000 Ford F250 Diesel air cond problms
 

ck for vac on the black hose coming in the cab. if no vac there ck the pump for vac.

Re: 2000 Ford F250 Diesel air cond problems
 

that makes sense kinda what I was thinking---No problem with heat or cold when the temp is adjusted it gets hot & cold--I never paid any attention to the pump before does it kinda vibrate a little while running ? or what--It definitely IS running just not sure if its making vacuum---any way to test it and how much vacuum is normal?? thanx for the reply

Re: 2000 Ford F250 Diesel air cond problems
 

checked the hose nothing real apparent ---the pump was running while the engine was running ---how long is the pump supposed to run??---how much vacuum is this pump supposed to pull-- might just be a "worn out" pump hell its 15 years old-- just do not want to spend $45-60 bucks for a pump when its "only" a cracked leaking hose

Re: 2000 Ford F250 Diesel air cond problems
 

The search I found stated the vacuum pump should produce 17-21" of vacuum. If the damper is in defrost is also a sign of not enough vacuum. A cheap hand operated vacuum pump will diagnose a bad hose or damper diaphragm, and could be used to show what the vacuum pump is pulling. What is the brake pedal like?

Sean

Re: 2000 Ford F250 Diesel air cond problems
 

thanx guys--we are gonna replace the pump tonite with a known good pump see if that fixes it---all the hoses look pliable not rotted or chafed etc. Will let u know what it was--FED 387

Re: 2000 Ford F250 Diesel air cond problems
 

Is the truck a 4x4? If it is and it has the electronic shift on the fly (esof) it probably has bad hub seals which allow dirt to enter the vacuum lines and wear out the pump. Like Sean said it should be at least 15" of vacuum. Hope this helps.

Re: 2000 Ford F250 Diesel air cond problems
 

TWO WHEEL drive !!!

Re: 2000 Ford F250 Diesel air cond problems
 

OK finally got around to replacing the pump with a known good pump--- still sameo sameo still defrost only---pulled the glove box out looked under there nothing looks bad---possibly the "selector" is bsd???---without tearing the whole dash apart anyone got any other suggestions?? Thanx FED 387

Re: 2000 Ford F250 Diesel air cond problems
 

I just checked and the A/C compressor is also engaged in any position except off-- not matter which position the selector is in EXCEPT off the a/c compressor is running

Re: 2000 Ford F250 Diesel air cond problems
 

My 2001 F350 dsl dually had a canister on left side facing motor near ac box on the firewall the bottom of it had a pinhole that caused a leak so ac didn't come out of vents but defroster only= the canister is about the size of a quart bottle with vacuum lines running to it hope this helps bobby

Re: 2000 Ford F250 Diesel air cond problems
 

Yep know exactly where it is thought about checking that too-- with all the vibration and the age of the truck makes sense the plastic finally gave out ---how did you locate the pin hole what test did you use???

Re: 2000 Ford F250 Diesel air cond problems
 

Kind of right behind the battery, mine I could see the pin hole , all u have to do when u pull off is pull vacuum or blow air into it, u can by pass the canister with the vacuum hoses to see if cures the problem then search for leak in tank

Re: 2000 Ford F250 Diesel air cond problems
 

OK--so far I have replaced the pump and the reservoir with a known good pump & reservoir--- chased down all the vacuum hoses none appear to be chafed or worn--- how about the control selector on the dash anyway to test it ? or do they just "go bad" looks like its all plastic so no way to take it apart the hose is fastened to the selector not hanging or anything- changing it from any position to another( vent/AC/heat/defrost) changes nothing STILL ONLY DEFROST !!!-- looked under the dash/glovebox area nothing appears out of the ordinary there---any suggestions other than replaceing the selector knob---truck is 2 wheel drive and has AC---thanx FED 387

Re: 2000 Ford F250 Diesel air cond problems
 

Run a vacuum line directly from the pump to the damper actuator. Or buy a hand vacuum pump and do the same. Eliminate each device. But if you start at the actuator and it moves and stays in position it should be ok. The rubber diaphragm may be cracked and is leaking.

Sean

Re: 2000 Ford F250 Diesel air cond problems
 

SEAN-- OK --so where is the diaphragm located??

Re: 2000 Ford F250 Diesel air cond problems
 

It's attached to the blend damper, somewhere under the dash.there could be more than one actuator. Looks like this.

http://www.oreillyauto.com/site/c/de...+door+actuator

Re: 2000 Ford F250 Diesel air cond problems
 

OK got it will check that out too--thanx FED 387

Re: 2000 Ford F250 Diesel air cond problems
 

This is for reference only as it is for a Ranger, but a picture is worth a 1000 words.

http://www.ford-trucks.com/forums/at...ntid=517&stc=1

Re: 2000 Ford F250 Diesel air cond problems
 

OK Sean--- how do you know wether its a good one or a bad one? by using a hand actuated pump its supposed to move correct if it doesnt move its bad right---these things are a little pricey dont want to buy a 1/2 dozen til I hit the right one!!! --Thanx FED 387

Re: 2000 Ford F250 Diesel air cond problems
 

With pneumatic actuators we apply pressure, and with a pressure above what is above the actuators spring pressure it will move. In this case its vacuum, but the same principal. With the 17-21" w.c. rating of the vacuum pump, the actuator should stroke to the full position, and remain there. With what you are describing chances are if you apply 17-21" of vacuum directly to the actuator, if it moves and stays fully stroked, it is fine. Work backwards from there until you find what is damaged or unhooked. It could be as simple as the vacuum line is disconnected or cracked at the actuator.

Sean

Re: 2000 Ford F250 Diesel air cond problems
 

Sean-- thanx got my Sat AM all set up for doing this--Regards FED 387

Re: 2000 Ford F250 Diesel air cond problems
 

OK --found it!!!! the insulatution they put around the battery over time had worn a TINY !!!!!! pin hole in the seam of the vacuum reservoir cannister--- even under water it rarely bubbled--- so I siliconed it for now but I have a BRAND NEW cannister coming--- the one we used that we thought was good had an even smaller leak but it did leak---

Thanx to all that rfesponded--- FED 387