Question for Ford Mechanics

[Jigstick]

Noticed some humming coming from the front end. Checked the wheel bearings and the usual culprits which were all normal. This lead me to check out the IWE system.

I checked both front IWEs with my suction pump and both hold pressure and disengage appropriately. So those seem good.

Next I went to trouble shoot the vacuum lines. I’m getting good suction on the drivers side line, and the drivers side IWE stays unlocked in 2WD. However the passenger side vacuum line doesn’t have any suction while in 2WD. And is locking up that IWE.

I can’t figure out for the life of me why one side would have suction, but not the other. To me it looks like one continuous run of tubing. If there was a hole anywhere in the vacuum lines wouldn’t both sides lose suction?

What am I missing??

 

[Duc]

Best info I can find;

Everything You Wanted To Know About The IWE System...And Then Some - Ford Truck Enthusiasts Forums

2004 - 2008 F150 - Everything You Wanted To Know About The IWE System...And Then Some - After my recent experiences with the complete IWE system i decided to write up a description of the system and troubleshooting. Hope this helps out some people! Maybe this can become a sticky! When the system...

www.ford-trucks.com

 

[The D]

No experience with this specific problem but there are great diag write-ups online

Just one that I found

Everything You Wanted To Know About The IWE System...And Then Some - Ford Truck Enthusiasts Forums

2004 - 2008 F150 - Everything You Wanted To Know About The IWE System...And Then Some - After my recent experiences with the complete IWE system i decided to write up a description of the system and troubleshooting. Hope this helps out some people! Maybe this can become a sticky! When the system...

www.ford-trucks.com

Edit: Ah, duc beat me to it by a few seconds!

 

[Jigstick]

Yeah I read those last evening when I was trouble shooting. I just can’t figure out why I have vacuum on the drivers side…but not on the passenger. It’s one run of vacuum line, with a single T fitting. I would think if there was a tear anywhere in the line then both sides would lose vacuum. But that’s not what I’m experiencing

 

[JMGlasgow]

There is a new check valve for that system. It is blue and located on the firewall near the brake master cylinder. If it isn't blue it needs to be replaced. Maybe that will help. Or you have a pinched vacuum hose.

 

[JMGlasgow]

 

[Jigstick]

I thought maybe a the line was pinched on the passenger side. So I hooked my pump up to that line right at the IWE and I can’t get suction pressure. So to me it seems more of a leak somewhere than a pinch. What a fucking headache. Looks like I’m going to have to hit up the dealer and order a whole new vacuum line kit…or rig up something generic with generic vacuum hose from the parts store temporarily. Have a 600 mile trip in a couple days and don’t want to drive it with the passenger IWE engaged

 

[Jigstick]

Spent 2hrs replacing the vacuum lines. It’s fixed. No idea where the leak was. I looked all over the old lines and couldn’t find a crack or tear. Very odd.

Dealer didn’t even evaluate the IWE system. They jumped right to telling me the front differential needed opened up for $750 + repairs. I spent about $125 to fix the issue in my garage. wtf

 

[The D]

Spent 2hrs replacing the vacuum lines. It’s fixed. No idea where the leak was. I looked all over the old lines and couldn’t find a crack or tear. Very odd.

Dealer didn’t even evaluate the IWE system. They jumped right to telling me the front differential needed opened up for $750 + repairs. I spent about $125 to fix the issue in my garage. wtf

Unfortunately the dealer techs get the best $$ on customer pay service work, not diag work

This coming from someone who spent a little over 10yrs in a dealership shop(though it was Mercedes not Ford)

 

[rijndael]

It's tough to beat a smoke machine for finding vacuum leaks. There are a few on sale for Amazon Day deals. They start at $75.

 

[Gunfighter14e2]

It's tough to beat a smoke machine for finding vacuum leaks. There are a few on sale for Amazon Day deals. They start at $75.

Shaving cream is cheaper, and the hole where the leak is, very easy to see. Its been used for that almost 100 years.

 

[rijndael]

It’s not easier to see when the leak isn’t reachable without disassembling stuff. Tank filler necks are one good example, and so are things on the top of the gas tank. I’m not going to slather an entire vent system in shaving cream.