Search found 44 matches

by 69DropTop
Fri Sep 13, 2019 9:51 pm
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

I pinched off one of the heater core lines with a set of vise grips then took the truck out for a spin. I got 42 degree air out of the vent. I removed the vise grips and the temp went about by about 8 degrees :evil: So, I guess that answers the question of why the pressures and everything seem right...
by 69DropTop
Wed Sep 11, 2019 5:06 am
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

Next is to find out why you are reheating the evap air before to reaches the vents. Ok, so do you think the in/out temps seem right and the pressures seem right? I guess you think that heat is getting introduced back into the cool air somehow/somewhere? I didn't get a chance to last night, but I ca...
by 69DropTop
Tue Sep 10, 2019 4:26 pm
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

The liquid line to evaporator was 46 degrees and the evaporator to accumulator was 43 degrees. I took both measurements about an inch from where the lines go into the HVAC box.
by 69DropTop
Tue Sep 10, 2019 11:39 am
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

Heater valves fail. Also check the evaporator for crud. A plugged up air side will give poor performance, and considerable cooling of the suction line. A 10 year old pickup truck may have an evaporator full of leaves / dog hair / mouse nests... At lunch I looked at the heater hoses into and and out...
by 69DropTop
Tue Sep 10, 2019 7:31 am
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

I don't see why the pressure readings wouldn't be accurate. Good point about hot water getting into the heater core. I haven't noticed a hot water shut off valve but haven't looked closely for one either. Do all cars have hot water cut off valves for when the A/C is on? I know my '69 Cougar does but...
by 69DropTop
Tue Sep 10, 2019 6:41 am
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

I posted my pressure readings but didn't get any replies. From the little I know, I don't think the readings are bad but it cools better at idle than when going down the road so that makes me think it could be slightly low still. I put somewhere between 40-42oz of refrigerant in it. I read online th...
by 69DropTop
Sat Sep 07, 2019 2:12 pm
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

I got some low/high side readings. Here were the test conditions: outside air temp 77*, I parked the truck in the sun, opened the doors, set fan on high, set ac on max, had driven truck with a/c on prior to testing, held the engine at about 1500rpm and got 27 on the low side and 190 on the high side...
by 69DropTop
Fri Sep 06, 2019 9:22 am
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

I don't have pressure readings at 1500rpm yet but can get those tonight or this weekend and report back. I do know it was right around 30 at idle.
by 69DropTop
Fri Sep 06, 2019 7:18 am
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

I knew the fan was supposed to be on high and set on max but didn't know windows were supposed to be down or doors open. The sticker calls for 40oz. I put 3 12oz cans in and between 1/3 to a 1/2 of a 4th can. I did have a similar test scenario last night- fan on high, set on max a/c, held throttle a...
by 69DropTop
Fri Sep 06, 2019 6:33 am
Forum: Automotive Air Conditioning Forum
Topic: '99 F250 Super Duty- immediate low side drop
Replies: 22
Views: 11431

Re: '99 F250 Super Duty- immediate low side drop

I installed a new orifice tube last night, vacuumed the system and then charged.  It was about 74 degrees outside.   When I went out for a test drive the best temp I would get out of the vent was about 45 degrees and it went up to 51 when I'm guessing the compressor was off.  With outside air temp o...