Front axle vacuum lines

[Diesel_Fitter]

All,

Just want to verify with someone as I don't have a repair manual yet.

I was changing out the brakes on my 2000 7.3L over the weekend and I notice what I believe is a 4X4 vacuum line near the hub on the axle was disconnected. What looked to have happened was the vacuum nipple rusted and broke in half. I probably should have taken a pic but I was filthy at the time. Can some one confirm that this is indeed the 4X4 activation vacuum line? I tried looking on the ford parts website too but that doesn't help much.

Thanks guys,
Greg

[justinlogue5_0]

Do you have manual lock out hubs? If so I think the lines your talking about are just breather lines to relieve preasure. Some one else will chime in I am sure.

[Diesel_Fitter]

I actually have the electronic 4x4 selector switch on the dash.

Greg

[justinlogue5_0]

I do as well but my hubs are manual. If you don't lock in the hubs it doesn't matter if its in 4x4 or not. The front wheels won't pull unless your hubs are locked in. On a full automatic front end, the hubs are locked in full time but the wheels won't pull untill the front drive shafts turn which is done by locking in the transfer case (turning the knob on the dash). I really believe they are just breather lines which should still be fixed before you go driving through mud and rain puddles.

[flf250sd]

That fitting, with the rusted out nipple, is most likely for your ESOF 4X4 hubs. I had a similar problem, but the vacuum line on the passenger side wheel was torn apart (due to age I believe). I examined the fittings in the hub, and I noticed the nipples were severely rusted, so I replaced them, along with the vacuum lines. At this point in your repair, you may as well do the same. It's not expensive, and it will give you peace of mind. You might want to consider rebuilding the ESOF hubs too.

[zpd307]

that is most likely the vacuum line for your lock outs. the hubs are not always locked in with the auto hubs. the hubs use vacuum to pull in the a diaphram to lock the hubs when the selector switch is turned, on the dash. there are some truly manual hubs out there, but most seem to be the esof hubs, which have the back up manual locking feature.

[justinlogue5_0]

Superduty auto-locking 4X4 hubs - Page 5 - Ford Truck Enthusiasts Forums

This might help you all as well.

[melmount]

just remove the vacuume line and put a plug over the end thats attached by the frame. That way theres not a vacuume leak causing the small vacuume pump to run all the time.

[martiin]

Originally Posted by flf250sd

That fitting, with the rusted out nipple, is most likely for your ESOF 4X4 hubs. I had a similar problem, but the vacuum line on the passenger side wheel was torn apart (due to age I believe). I examined the fittings in the hub, and I noticed the nipples were severely rusted, so I replaced them, along with the vacuum lines. At this point in your repair, you may as well do the same. It's not expensive, and it will give you peace of mind. You might want to consider rebuilding the ESOF hubs too.

I just found the rusted nipples on my 2001 - where did you find replacement nipples - Ford wants me to buy new hubs to replace nipples!

[ttyR2]

I don't know what size the nipples are, but I'd look for stainless steel replacements. If they are anywhere near the size of a brake bleeder nipple, those can be had in SS.