2000 f150, 5.4 4x4.
was told by a member here I need o-rings kit for the vacuum lines, I have vent air on deceleration and only defrost on cruising or acceleration. It seems to switch back and forth.
The o-ring kit that I find look like they are for frion lines.

Can someone direct me to the correct kit?
Also, can anyone point me to the location these go?

This morning I switched to heat and found out the heat quit working too. It's cold air and occasionally switches to slightly warm air for a few minutes.

Is this the same problem, or something different?

Thanks

 

If.... That's your problem you just have to match the o-rings up. You're not going to find anybody selling them for that application... It was intent not intended to be repaired.

Good auto stores will often be able to sell you o-rings and match them up from a big kit they have.... Or industrial parts houses like motion industries etc. When I go into my local one the counter guys just give me stuff because it's not worth their time to write it up on sales ticket for a couple of o-rings or small bolts or such that's going to total less than 50 cents

 

Oh ok, great thanks. Now the passenger side windshield wiper quit working as well. 😬 Starting to think I might should dump this truck and look for another.
I understand it's an old truck, but for a whole list of things to go wrong in the first day after purchase, it's not a good sign. Haha

 

Some people maintain their vehicles and fix everything, and even do things proactively. Others run them into the ground never fixing anything when they get some age on them.

There could be a lot of things that need fixing on your truck. It's 23 years old. But these trucks are worth fixing they don't have problems that keep recurring that can't be fixed. The interior doesn't break and fall apart, and rattle.

Most fixes are pretty easy and well-known.

 

That's good to know, it makes me a bit more confident in it, once I get all this stuff solved. 👍
If anything breaks on one of my trucks or quits working properly, or a dash light comes on, it bothers until I figure out what it is and fix it. What really interested me about this truck is that it seemed the same way, whoever had it before really stayed on top of making sure everything kept working properly.

So what made me start thinking it was a mistake getting it was that it went from almost no problems to a list of problems in 24 hours. But as long as that trend doesn't continue I will enjoy it 👍

I understand that problems on a 23 year old truck are expected, that's ok. But I can't keep up with 10 new problems per week. Haha. Hopefully this will calm down a bit after these fixes. Truck gets brake rotors turned today, and oil leak fix at the shop tomorrow. About to jump into the windshield wiper issue and ac/heat after lunch now

 

Update, I guess the system that doesn't have climate control is different, mine doesn't match the one in the video. On the back side I have a simple square box behind the selector ****, which doesn't seem to come off. The nipples that the hoses go on do not seem removable either. Does this type have o-rings inside also, or is this just a sealed system? Not sure if this could still by my leak inside, or if it is in the hose lines somewhere instead. I can't find a hole or leak in any lines. Maybe I need to just buy a whole control panel?
Edit: box is available in stores for 55 dollars, I may try a few more searches on the hoses before getting it. When I took the box out a bb fell out of the box and I have no idea where it came from. So I may end up needing a box anyway now. I'll plug it back in and try it and see if it was anything important I guess. Lol

 

Post a picture of your control panel.

This might or might not be part of your problem, but it's worth watching. There are many like it.

Vacuum and/or blend door.

 

Thanks for the links. I did test the one in the first video under the steering column. It seems to be holding vacuum.
I haven't tested the one in the middle under the radio, but it may be why the air won't get completely hot, and switches between warm and cold randomly. It seems to be electronic and not vacuum, but it could still be broke
The issue with the vents seems to be vacuum related, since it changes with rpm. I have been wondering if one vacuum issue could be causing the vent/defrost and the air temp to both be affected, or if I am dealing with two different issues here, one being vent/def, and the other being temp. I just purchased a new control box that goes on the back of the controller ****, and I'll see if that does anything.
I'll also pull off that lower cover and see what that blend door is doing, it may be a different issue all its own.

 

Can't tell if you have electronic or manual.

The vacuum systems always have a check valve. If things change with engine vacuum it's almost always a stuck open check valve, or a leak in a vacuum line. Or o-rings as already suggested. Pretty sure that there's a vacuum reservoir bottle somewhere also. Not sure where.

 

Found a check valve under the hood by the firewall, tested it and it looks good.
Went ahead and brought the little control box that was attached to the back of the head controller unit to O'Reilly Auto parts, they had one for $55.

This one cannot be taken apart to replace o-rings, so I went ahead and replaced the whole box (pics and part number below). The full climate control systems are the ones that have the o-rings, the basic units just have the sealed box it seems. The box just clips onto the back of the head unit.

It works! O-ring type would have been cheaper, but it was nice to just disconnect one and connect the other and be done, so that's ok.

As far as temperature control, I'm not completely sure yet. When I started driving it still would only blow cold air. I played with the temp **** some and got hot air to come out. Then it started going cold again, so I turned it back and forth again, and it stayed hot from then on.

Along the test drive I changed the temp **** occasionally to see if it would mess up again, but it never did. So I'm not sure what's going on there, but it works at the moment. Not sure why it decided to start working, or if it will continue to work, but if not I think the blend door would be the issue, so at least I know where to start next. 👍