Thread 2937336

Got a 2004 f150 5.4 litre triton.
It's been wrecked.
It's just kind of a piece of shit. But I love it and use it regularly.

Air would work for 5 minutes or so. Then be ambient temp or warm. Not hot.
Both windows don't work.
I grab a sc recharge kit.

Car off connect to low pressure side
It shows pressure.

Assumed no leak.
Start car, turn ac full blast, recirculating on.
It test right on the edge of low (just shy of 30 psi).

I dump the can in, I shake it rotate it, etc, It never goes above 32 psi.
Can is empty.
Air is working alot better and lasted for a hour long car trip.


What gives? I thought it was supposed to go to 40 psi before it was considered full. I hesitate to get another can to put more in cause the truck is old why didn't the psi ever go to 40? What do I not know that I should.

I'm a contractor not a car guy. Is it normal for a truck to take more than 1 can? Do I have a small leak that doesn't allow the full psi?
What gives? What do I not understand?

Pic related, connected to line circled. The entire can went in aside from a little spray back from the top of the can. It dripped a little.

>>2937336 (OP)
>Is it normal for a truck to take more than 1 can?
probably if its empty from all leaking out. theres usually a tag by the fan cowling that says the charge volume

>>2937339
It's never been recharged.

You think it's worth it to get another can?

>>2937339
Would a leak still be possible even though it tested like 60 psi on the low pressure side while the truck was off off?

>>2937345
its probably a slow leak. i wouldnt worry about it unless you get sick of buying freon
non running pressure doesnt tell you jack shit. hi/lo are what matters

>>2937348
If you care to can you elaborate. I'm handy and as long as I get the general gist I can usually carry myself.
Only the hi low matters?

>>2937352
when the compressor/engine isnt running the pressure equalizes in the sealed system. this has no bearing on the operation
when the compressor is running the low side fill port pressure will give a good clue to the charge level of the system. consider the low pressure the reservoir volume. it needs to be 50-60psi so the compressor is has enough feed to boost the high pressure up to 200 or so. basically the higher the pressure the better it will cool but if it gets too high the coil will freeze over and block airflow thus causing everything to quit working
its more complicated than that but thats enough for my hillbilly comprehension to do backwoods hvac repair

>>2937339
FYI if anyone wants to do this, here is the adapter you need.

>>2937336 (OP)
Visit Ford Truck Enthusiasts forums for any questions on that era F150. You'll find or get specific answers from the many current and retired mechs there regarding any Ford truck. I've used that site for many years for info on many Fords.

Generally the cure for leakers is parts and seal swaps. Condensers pinhole, static seals seep, pump seals wear etc.

My F150s have the same system (1997-2004 era) and the fix was typical for anything that old. I replaced the condenser, pump (which had failed) receiver-dryer, orifice tube and all lines and hoses then pressure test with nitrogen after injecting fluorescent dye to find any remaining leaks.

The nitrogen cylinder (buy used since they're refilled by exchange anyway) and regulator aren't expensive and last a lifetime. Also have a vacuum pump so you can evacuate the system before filling. Compared to labor rates this stuff is a bargain. Check Fecesbook Marketplace for deals but I'd pay retail if I had to since doing all my own vehicle AC work saved me shitloads of money.

Op here. I appreciate you guys. It's a torn up farm truck. I just wanted the air to work. It was a toss up between fixing the windows of air and the air seemed cheaper atm to get me to winter.
>>2937356
Yea. I read to connect the guage to the low pressure side with the engine off and if it reads 0 psi you got a leak and dumping r134a be dumb. I was expecting to have a leak but was surprised when it was just low.
It caught me off guard when it ate the entire can and I was worried I overcharged it.

>>2937367
Should I get a 4 hose manifold set? I read you can place the evacuation hose into a bucket of water.

>>2937375
i've been driving a farm truck for 10 years, AC never worked, always assumed it had a big issue
this summer has sucked so i took it to a shop and was like 'what's up?"
evcuation and recharge, $180
has worked flawlessly for months
feel like an idiot but fuck yeah this is great

>>2937337
Had a similar issue myself with my Honda. I used about half the can. The pressure went up but I felt I was doing it wrong. The seal isn't the greatest with that can. I did help a little but my car ac still struggles on very hot days.

>>2937395
>place the evacuation hose into a bucket of water
dont do that
moisture is the enemy of a working refridge system. it turns everything inside to goo tar
the stop leak shit isnt much better either

>>2937441
I would never do anything I didn't know what it did.

I don't know enough about cars to be hooking different fluids or or draining shit this way. Thanks for letting me know it wasn't back following from pressure and that the seal sucks. That explains the drips cause I wasn't exactly gentle.

As long as it works a little better im happy and it does. It's not shooting ice but my truck isn't 130degrees. It's a nice manageable 80


Prior to doing this I was opening my cooler and taking the bag of ice and putting it on my lap.

>>2937407
I meant to respond to you too here
>>2937444

I put 40 $ into it and if it last 2 weeks it be worth it.

It doesn't sound like I fucked up anywhere and I didn't over pressure the compressor. I got a little nervous when it ate that entire can.

>>2937441
I meant, instead of capturing the evacuated refrigerant into a bottle, you can safely empty it to atmosphere by placing the evacuation hose into a bucket of water so refrigerant isn't shooting everywhere.

>>2937484
I didn't evacuate any. I just attached the hose and recharged it. It was low psi on the guage. Like 28. When I emptied the can it was closer to like 32.


Was I suppose to bleed it first? I could connect that line and open the valve. I like in the middle of nowhere.

Op here.
Did I mess up and skip a step? Was I suppose to drain the ac with the engine running before filling it with the r134a?

>>2937489
No you're good

It's a lot easier to tell what's going on with a real refrigerant manifold gauge set like >>2937395. A car's AC system will refuse to run both if it's too low pressure and also too high since they have high pressure cutoff switches. Extremely high pressure/too much refrigerant will display the exact same symptoms as too low from a layman's perspective. Poor cooling, frequent cycling of compressor or the compressor just won't turn on at all. A real manifold reading both high and low pressure simultaneously will instantly tell you which one is your problem.

Being 20+ years old it's very possibly just low. Automobile AC systems have a life expectancy of holding refrigerant and they all leak out through the hoses eventually. 2 decades is about that time. Of course being a 5.4 Triton I'm shocked it's still alive at all especially an early one that'd be my bigger concern. Yeah stop leak isn't "good" for the system but at 2 decades I'd see if it doesn't have a MASSIVE leak and if it doesn't, dump 134a with stopleak in it and send it. It'll likely last until the rest of the truck is ready for scrap.

Everyone should have a basic gauge set that can do home and auto systems. With VC eating the planet air conditioning repairs are getting ridiculous.

The best way to get a system running well in a car is to drain the system (recovery machine at AC shop or a cheeky atmospheric recovery), run a vacuum on it, quickly swap the drier, run vacuum a second time, and then charge to specification weight. I find in a lot of old cars they have moisture or non-condensables that hinder performance. A new drier and fresh vacuum and charge will get your shit blowing absolutely ice cold, assuming no other issues.

>>2937336 (OP)
Hello, my work involves hvac and I've helped a few people repair their vehicle's hvac.
Sounds like you have a leak on the high side, which is why it will hold 30 psi but not more. Most leaks occur in the high side of the system, due to the high pressure and temp. Get a good light and check all of the connections between all of the lines, and where metal transitions to rubber and vice versa. Oil will come out where there is a leak, so look for oil stains on the lines and/or sand stuck to the oil.
If you can't see anything obvious, mix dish soap and water in a spray bottle and spray all the connections and look for bubbles. Bubbles indicate a leak.
To repair leaks, buy an automotive hvac oring kit (green) off amazon. Evacuate the system charge till no pressure. Then unfasten the leaking connection and replace oring. Look up your truck on yt for specifics. Some trucks have gasket washers instead of green orings, so do your research. Replace leaking orings, button everything back up. Then pull down into a vacuum using a harbor freight manifold and vacuum pump. Let sit for several minutes, making sure the pressure doesnt rise, which would indicate you still have a leak. Then recharge your system with the factory charge on your underhood sticker. Lots of tutorials out there to help with any steps you have questions on.

>>2937544
I use dawn and water bubble method to find holes in tires.

Before taking off the low end I unscrewed the high end because I was curious and willing to blow out the system to learn.
I got a super small hiss. Like fraction of a second and there was a o ring around the high connection sight.
I don't know if this is pertinent or helps.


This explains why it wouldn't charge higher.
This now leads me to.
This truck is from 2004. The brake lines are held together with zip ties. The bed is rusted out, it's got 140k miles, only the back windows work and I ripped off the door panels for other repairs.
It's been wrecked and I used the money from the woman hitting me to put a bathroom in my basement home. You need to slam the driver door for it to jump and mount closed.

Is it worth a repair kit or looking for the leak if all I'm trying to do is make sure the cab isn't 120 degrees?

I went for a hour long trip, it would usually "cut out"(stop being cold and being ambient) in 5 minutes. It kept a cool, not cold, flow the entire hour and I wasn't sweating my balls off.


Your awesome.
>>2937532
I agree. I cna build a house foundation to roof. With that knowledge tell me the basics and where to go read or learn better. Obviously youtube. But I don't know what knowledge I need.
Imagine a electrician telling a home owner to go learn about 3 phase.
Useless knowledge for 90% of people but it is electrical.
Im getting older and really need to zone in to learn.

>>2937493
I feel better knowing I'm not going to blow it out and have 0 air next time I use the truck.. Thanks!


You can see in Pic related it's not cleaned or like well maintained. I will park where I'm working and open all the doors and work off the tailgate.

>>2937407
I read this alot and feel it so hard cause I went that entire heat dome with no ac sitting on bags of ice when 40$ got it working well enough.

>>2937597
Slowly leaking schrader valves are super common. The black caps that go over them have an oring that usually seals well as long as they're tight enough. The hiss means the cap did it's job. For your system to lose performance that quick, I think you have a larger leak somewhere else. If it's an oring or hose, those are cheap, just use amazon desu. The biggest cost will be tools, not parts. For tools I recommend going to Harbor Freight if you're close buy, or buy off amazon. Good news is, once you buy the tools you'll be set for any vehicle with hvac issues. R134a, your refrigerant, is very cheap in 12oz cans from autozone. Get the ones without stopleak. Refrigerant is a standardized chemical compound so brand does not matter. Around $12 iirc. You can use the hose from that name brand kit you bought to charge.
For and torque specs or other specs, use the site charm.li it has OEM procedures for vehicles up to 2013, insanely valuable resource. Good Luck!

>>2937343
>It's never been recharged.
>You think it's worth it to get another can?
>>2937343

Get some with the stop leak. It was low because it leaked out. They sell stuff to seal leaks. It might take a few cans. The proper fix is to put some leak dye and find the leak and replace the hose. Then put under vacumn. Put the right amount of oil in the system and charge it the right amount of oz by mfg data.

>>2937616
>r143a
>cheap
It was half the price 5 years ago. I remember the cost of a can at Walmart well because in the late 2010s I had a shit box that would need 1 can a month in the summer to keep the AC cool and it wasn't worth fixing the leak. $4.88 a can. Shit's $9.98 now. Guarantee there's no justification for the price increase they just jacked up the price because fuck you everything else is more expensive so we'll charge more too.

>>2937616
Having worked construction, if a tool is 200 dollars and I need it once I just "rent" it from home depot and return it.
This information is helpful. I'm not a car guy but I'm handy.

Is it worth trying to fix? I was just gonna get the windows fixed so they opened and use the ac till winter this year. I'm. It trying to dump money into it.
It's at the end of its life.
If it holds 32 psi and works well enough should I Jie leave it one unless it drains out?
>>2937621
I used the shit with stop leak because it was the can I grabbed and I was under the impression 134a was 134a.

It did have stop leak stuff in it. I hope I didn't make it harder to find my leak.

>>2937625
Just wait till you see the price of r1234yf, the replacement for 134a from 2019+. Shit is ridiculous. I guess it seems cheap compared to the new stuff.

>>2937627
Up to you if it's worth it. If the leak is an oring or line and you rent all the tools, the repair could only be ~$40-60. If it's on the condenser it will be more. If the leak is on the evaporater I would say forget it.

>>2937692
Yeah I'm not buying 1234yf. 134a and 1234yf are exactly the same except for a very, very slight change in the oil used to lubricate the compressor. Same pressures within margin of error. You can put 134a into a 1234yf system without a single issue.

>>2937336 (OP)
Doesn't this stop leak stuff destroy your system after a while?

>>2937726
yes it will.
it will either wreck the filter dryer, a easy to replace part, but still a PITA
OR it will gum up the orifices inside the compressor... in which case you're buying a new compressor.

Never use any kind of stop leak if you can about your care.

One place for a leak that EVERYONE always misses is the electronic pressure switch, it's a switch that senses pressure of gas and lets the AC pump run.
No gas pressure = pump does not run.
Problem is the sensor is ALWAYS the lowest grade plastic shit possible and as the plastic has aged the refrigerant will eat a hole through the sensor.

seen so many people get ripped of having new coils or pumps installed to fix their AC when all they needed was a $10 sensor.

>>2937360
>1"-20 thread female to npt coupling
can confirm
currently 100 in my west coast liberal utopia. i should go set up the cash only hoopty ac recharge station for some fun money