'99 4WD Ranger. . .What are these connections for???

[atomicjoe23]

First. . .what is this metal tube going into the hub for???

This is on the passenger side hub and the metal tube is all corroded (to the point of breaking) and the plastic tubing is all dried out, hard, and brittle. . .gonna try to fix it, but it would be nice to know what it's for as well. . .my guess is for 4WD hubs to be locked in???

Second, there is this un-used sensor right next to the front ABS sensor QD's on both the driver and passenger side of the truck. . .what are they for???

Thanks!!!

 

[JoshT]

You are thinking right about that tube being for 4WD system. The 98, 99 and some 2000 models came from the factory with what are known as pulse vacuum hubs (PHV for short) which uses vacuum to lock in the hubs when in 4WD. That is the tube which supplies the vacuum to the hub.

Think you can get a better shot of your front hub? Does your 4WD actually work? I don't just mean does the light come on, but does the front actually engage and spin the wheels or do you know? The reason I ask is I suspect someone removed the vacuum lines because it doesn't look to me like they came loose on their own. I am suspicious as to whether you have the factory set-up on the front end. There are a few ways to make the 4WD work with loss of vacuum (a common failure on these). These include modifying the factory hub, replacing them with manual lockouts , and swapping components with a later model.

As for the plug, well I'm not sure. Can you get a better picture of that as well, maybe I should say broader or better angle? If I remember I'll look under my truck tomorrow and see if I can spot anything. No promises though, I seem to be forgetting thing a bit more lately. Guess I got to many things going with work, school, and trying to figure out how to build the other truck.

 

[atomicjoe23]

Thanks JoshT. . .I will try and grab some better pic's tomorrow. . .

. . .I bought the truck from the original owner and I can guarantee that he didn't modify the vehicle (I've known him for about 5 years now. . .and I can promise you he didn't mess with it). . .

. . .both hubs look the same. . .the vacuum line (that's what it is, I traced it back. . .I just wasn't positive what it was for) was still connected to the metal tube going into the hub prior to yesterday, I'm not gonna say that it was air-tight, but it was connected. . .when I touched it the tube just kinda crumbled away and voila. . .no longer connected (same thing happened to the intake manifold heater tube on my '79 F-150. . .fixed that by going to an Edelbrock Performer manifold and carb). The 4WD was working the last time I tried it out. . .I will have to see if it is working tomorrow after work, betting the passenger side isn't, but the driver's side is. . .

 

[James86]

The last pic is on the frame right? You don't have foglights do you..... I have the same plugs and no factory foglights on my 99 4WD.

 

[atomicjoe23]

Yeah, it's on the frame just behind the front bumper. . .no foglights and that would make sense.

 

[treeguy]

As for that corroded vacuum connection, that is not on purpose. Mine looked the same way when I was investigating last summer why my 2000 4WD would no longer engage. It turns out that they last about 10 years before they need replacing (I made an improvement to the pressed in type Ford wanted $80 for the replacement tube, I used stainless). I would get it fixed ASAP. It turns out that water can leak in there and rust up your expensive hub assembly (the part the CV joint slips into), thus requiring a costly replacement & you will get a functioning 4x4 again. Just my .02 cents!

 

[atomicjoe23]

Yeah, I ended up fixing that almost as soon as found. . .shortly after posting up on here; good thing to because then it snowed and I needed 4WD to get home!!!

 

[treeguy]

Nice! What method did you use to fix it? What are your thoughts on these vacuum assisted hubs?

 

[atomicjoe23]

Only a small portion of the hard line was corroded so cut the hard line off behind the corroded area, deburred the end of the hard line, replaced the vacuum line with a slightly longer piece of vacuum hose and hooked everything back up.

As far as the hubs go. . .they seem to engage and disengage fairly quickly and after a winter of snow I can say they definitely work, but I haven't really pushed them through anything more difficult than about one and a half feet of snow at this point.