Vacuum lines

[barbaroja]

Sorry for bringing this thread back to life. Not many that speak of this matters.

I am trying to figure out where exactly the yellow line connects to. I understand under the battery, there is a valve that works with the EVAP system to detect leaks. MY yellow line got burned so I do not know where it belongs to.

Any help is truly appreciated.

 

[donalds]

Pictures

 

[barbaroja]

This yellowish line

 

[barbaroja]

Nope. Just checked with an endoscope cam and can't seem to find where it goes. Any info is appreciated.

 

[donalds]

Look under the battery tray for a evap purge valve
Must remove the battery tray if you want a good look at it

 

[barbaroja]

Thanks for the answer, Donald. I saw that valve. So it plugs directly to it? I do see some wire connections to the valve but could not find the port. So I am guessing that valve takes both vacuum and electrical to work?

 

[donalds]

There is 3 lines 2 big ones and the one your tracking down
1998 FORD EXPLORER 4.0L V6 SOHC Vapor Canister Purge Valve / Solenoid | RockAuto
Here are some pictures on rock auto

 

[donalds]

Little more info Ford's Evap System: Operation & Testing | MOTOR

 

[barbaroja]

Great! Thanks, Donald, the pictures helped a lot. The port is located under the valve itself.

 

[239]

Anyone know the size of the vacuum lines? Looks like 4 mm to me but I’m wondering if anyone has actually replaced them.

 

[DR98FL]

I replaced the plastic vacuum lines on my 98 Ex with vac rubber hose that advanced auto parts sells. It is in bulk so you can buy what you need. Just match up the size in the store.

Get this kit below and your good to go.

Dorman Vacuum Fitting Assortment Kit 799-355​

The factory plastic lines just pull out of the rubber plugs. Use the new hose and a connector from the kit above.

The factory rubber plugs are also available at advanced auto parts. In a package of different factory connectors.

DR

​

 

[EB4X]

To add to what DR mentioned....I have an older small diameter spool of clear brake bleeder/misc tube which SNUGLY FITS OVER existing broken ends PERFECTLY....like it was made for it--surely still available at local auto parts.....if you're pondering repair spots as an option versus complete replacement.

 

[239]

To add to what DR mentioned....I have an older small diameter spool of clear brake bleeder/misc tube which SNUGLY FITS OVER existing broken ends PERFECTLY....like it was made for it--surely still available at local auto parts.....if you're pondering repair spots as an option versus complete replacement.

I’m chasing an rpm fluctuation at idle so I’m looking for small leaks that may not throw a code yet. Before I go replacing and testing more expensive parts. My plan is to replace all the red vacuum lines down to the vacuum globe. Something must be broken after 22 years.

 

[239]

I replaced the plastic vacuum lines on my 98 Ex with vac rubber hose that advanced auto parts sells. It is in bulk so you can buy what you need. Just match up the size in the store.

Get this kit below and your good to go.

Dorman Vacuum Fitting Assortment Kit 799-355​

The factory plastic lines just pull out of the rubber plugs. Use the new hose and a connector from the kit above.

The factory rubber plugs are also available at advanced auto parts. In a package of different factory connectors.

DR

​

That’s a good idea I’ll definitely consider replacing them that way. I think I may even have that kit from when I fixed my washer hose connections.

 

[EB4X]

I'm having RPM fluctuation as well at idle with some hesitation / surging when accelerating at medium speeds: 20 -- 40 mph that I've been trying to figure out for a while. Starts up and idles fine for a minute then idle starts pulsating/ surging up and down mildly until I put a load on it / put in gear --- if I drive it a few minutes than pop in park the pulsating is gone --but the mild hesitation / surging is always there in that range--not a jerking/ missing like ignition issue but more of a flowing hesitation / surge mix... -- varying on degree from day to day. I didn't find any leaks in my smoke test but didn't block off throttle body so could be "false negative".... might re-do that soon. Threw parts at it which helped / lessened it (compound issue) but not 100% gone. Are you getting hesitation as well when accelerating? Let me know if you resolve yours. (I cleared my CIL with installation of new cam synchronizer - no other CIL's )

 

[239]

I'm having RPM fluctuation as well at idle with some hesitation / surging when accelerating at medium speeds: 20 -- 40 mph that I've been trying to figure out for a while. Starts up and idles fine for a minute then idle starts pulsating/ surging up and down mildly until I put a load on it / put in gear --- if I drive it a few minutes than pop in park the pulsating is gone --but the mild hesitation / surging is always there in that range--not a jerking/ missing like ignition issue but more of a flowing hesitation / surge mix... -- varying on degree from day to day. I didn't find any leaks in my smoke test but didn't block off throttle body so could be "false negative".... might re-do that soon. Threw parts at it which helped / lessened it (compound issue) but not 100% gone. Are you getting hesitation as well when accelerating? Let me know if you resolve yours. (I cleared my CIL with installation of new cam synchronizer - no other CIL's )

My situation is a bit different, at idle my rpms will jump around from something like 725 to 680 all of a sudden then back to the 720 range. It’s not affecting my acceleration and no hesitation or anything like that. It just shakes the truck when it does it so it’s annoying. I replaced the cam synchronizer too on my ohv. I’ve replaced the iac valve and throttle body gasket recently and all of my gaskets down to the heads are relatively new (1-2) years. I’m checking the maf and replacing the vacuum lines.

Do you have a scanner to check your absolute tps position? Mine didn’t throw a code but would change from 19.6 to 18 by itself at idle.

 

[EB4X]

My situation is a bit different, at idle my rpms will jump around from something like 725 to 680 all of a sudden then back to the 720 range. It’s not affecting my acceleration and no hesitation or anything like that. It just shakes the truck when it does it so it’s annoying. I replaced the cam synchronizer too on my ohv. I’ve replaced the iac valve and throttle body gasket recently and all of my gaskets down to the heads are relatively new (1-2) years. I’m checking the maf and replacing the vacuum lines.

Do you have a scanner to check your absolute tps position? Mine didn’t throw a code but would change from 19.6 to 18 by itself at idle.

I performed a test on it and it checked out....later on I replaced it out of frustration ... no change.