IWE

I know it's not HEF material, but does anyone have a diagram or link to one for a 2013 F150 four wheel drive vacuum system. My hubs did the tell tale grinding when the vacuum drops going up hill. I changed the little one way valve on the fire wall, but it didn't solve the issue. I was going to ask for a printout when I was at the dealer, but was positive that was the problem, as I had the same issue with an older truck. They have made a few changes to my model, including a different check valve, and different location. Got to get it fixed so I don't ruin my hubs, and driving around in four wheel drive really sucks on the drive pave.

Is it one or both giving you problems? And I can tell from your post you understand how they work. Vacuum disengages them, lack of vacuum and they default to engaged. One or other bad accuator and loss of vacuum will allow them to grind. Or just a leaking vac line or hose.

sled dog said:

Is it one or both giving you problems? And I can tell from your post you understand how they work. Vacuum disengages them, lack of vacuum and they default to engaged. One or other bad accuator and loss of vacuum will allow them to grind. Or just a leaking vac line or hose.

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I can't really tell which side it is, and I haven't really taken the time to jack her up and check it out. I had the same issue with an 04, and replaced the one way valve on the firewall, problem solved. My 13 has a different valve, but I replaced it, it's less than 20 bucks. Same issue. It's fine if I leave in 4 wheel drive. I looked on line, but they just talk about that same valve. Shitty part is, that I gave my vacuum tester away this fall, because I had no use for it. But yeah it's kind of like the vacuum wipers on my old Willys jeep, they used to get really slow when you were under load. I'm thinking something might have happened when I put the winter tires on. I service my front brakes when I swap tires to try and keep my calipers from sticking. Might have knicked a line

I finally found a picture on a ford parts lookup site

I've heard those bellows fail often.

lantraxco said:

I've heard those bellows fail often.

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The guy I buy my aftermarket parts from said he sells a pile of hubs for those trucks

cuttin edge said:

My hubs did the tell tale

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I'll admit ...yet again, that I read this 3 times before I really understood what "hubs" you were talking about. I should really have more coffee in the mornings before I get on here.

Vetech63 said:

I'll admit ...yet again, that I read this 3 times before I really understood what "hubs" you were talking about. I should really have more coffee in the mornings before I get on here.

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Well, sometimes my wife refers to me as "The hubs" I wonder what that means? LOL

It's going to make me run out and get a new vacuum tester. Thumb test Vacuum at source, vacuum at the solenoid, vacuum at both right and left hubs. Jack up right side. Engine off, no vacuum, hub engaged. Start engine, hub dis engaged. Same for left side. FML! What was wrong with getting out and turning that little plastic thing and locking the hub in.

I had to go to a lighter grease in the hubs to get mine to work properly. They default into gear and as your driving they start to disengage because things warm up and the hubs then will unlock. Sometimes its a hellofa bang when they come out too. This has happened on my 2011, 2015, but im driving a 2020 now, but it hasn't got cold enough to be a problem....yet.

grandpa said:

I had to go to a lighter grease in the hubs to get mine to work properly. They default into gear and as your driving they start to disengage because things warm up and the hubs then will unlock. Sometimes its a hellofa bang when they come out too. This has happened on my 2011, 2015, but im driving a 2020 now, but it hasn't got cold enough to be a problem....yet.

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This one has always worked smooth. I had an 04, and just replaced the one way valve. Problem solved. This one started grinding when you lose vacuum while stepping on the gas. The one way valve is a bit different, but I changed it anyway. Didn't fix the problem this time. I pulled lines off with it running and put my thumb on the line, and I have vacuum right out to the actuators on both sides. Jacked up each side, and they both free up the axle with vacuum on. I'm thinking the one way valve I replaced might be bad, or the reservoir tank is cracked. I had a vacuum tester but gave it away as I hadn't used it in years, and didn't figure I would ever need it again....wrong. Been kind of hanging off on trading, holding out for this mystical new Bronco