4x4 ESOF vacuum problem....'01 F350
#1
05-28-2009, 05:11 PM
4x4 ESOF vacuum problem....'01 F350
New to the forum and thought I'd start off with a ESOF problem I've been having...
I drive a 2001 F350 CC 4x4 7.3l....I have read through a few searched threads and cannot get a definite answer....so I figured I'd give my scenario and see what the masses think.
In auto hubs.....I turn ESOF on....light delayed a little but reads 4x4 and 4x4 low....I do not hear the 4x4 HI engage however I can hear the clunk in 4x4 LO. Does not appear to be in 4x4 in HI but is engaged in Lo.
In manual hubs, truck engages in 4x4 high and low. Hear distinct engagement. Truck does fine driving
I use my 4x4 on occasion at the deer lease. I also run my 4x4 HI after every 5-7L oil change from the front of my subdivision to the back when I return from the change just to keep it "used".... its about 800 yards and I don't get over 25mph. This recent episode just showed up a short time ago and I've been putting it off.
The passenger front hub was replaced at 190K.....driver front hub still going strong as far as the bearings go. No problems switching from auto to manual at the hubs.
Did some initial testing and here is what I have found to date:
After thinking my AC hadn't or wouldn't switch to defrost, it did when I started jacking with the ESOF switch. It did however kick back down to the dash vents eventually. Now when turning the switch to 4x4 Hi, all I heard was a click and the axles after a minute were still free spinning. I placed it in neutral, pushed on brake, moved it to 4x4 Lo and heard the tell tale clunk....however the axle was still spinning freely......
Now when I do this in the street on a long straightaway in the subdivision, I can feel the truck in 4x4 Lo after the clunk above. However I feel no clunk/engagement in 4x4hi ....
My vacuum pump is also kicking on and working....and seemingly every time I start the truck. I would think this would not be necessarily good.
OK...some more tests......
Vehicle off....
Pulled solenoid lines off to hear a gushing of air coming out. Turned vehicle on, vacuum pump on, 4x4hi on and no vacuum felt from solenoid. AC goes to defrost. Hooked back up and AC went back to vents. 4x4 hi "click" but hubs spin freely.
Vehicle on...
Lines looked to have black particles coming off them and turned my hand jet black. No noticeable leaks/cracks but the lines will be replaced either way as they are rotting. Cut off inch on both sides just to see if that would solve problem. Nothing.
Pulled vacuum lines individually to add golf tee to check vacuum. Did driver side hub with tee first and there was no switching of AC. Replaced drivers side line and plugged passenger side hub with golf tee.... after 30 secs the AC switched to defrost.
Plugged both lines with golf tees and AC went to defrost.
Next some tests while moving...Switched hubs to manual on straightaway in subdivision. Switched ESOF to 4x4 Hi and the axle kicked in immediately. Same for 4x4 lo in neutral. Making sure I didn't turn in 4x4, I did this for a couple of straightaways in my subdivision with no problems. 4x4 seems fine when hubs are manually locked in.
Switched hubs back to auto and son of a gun, the 4x4 hi works....Did this numerous times turning 4x4 off when I had to turn. Got in a long straightaway and put it in 4x4 lo. It too worked. Drove it for 30-40 yards and switched out.
Here's the kicker...after switching it out of 4x4 low, it would not go back into 4x4Hi again.... I made another block and was unsuccessful getting it back into 4x4 hi. The switch would click and the light would come on but the axle did not lock in like earlier....
Replaced the rotting vacuum lines from frame to hub and had the same results. I am leaning toward a bad or intermittent vacuum solenoid/valve assembly, but haven't been able to confirm it. Any other thoughts? or tests to run?
Sorry I'm so long winded....I've just been do a ton of research and tests to get this fixed....thanks and I appreciate any feedback.
I drive a 2001 F350 CC 4x4 7.3l....I have read through a few searched threads and cannot get a definite answer....so I figured I'd give my scenario and see what the masses think.
In auto hubs.....I turn ESOF on....light delayed a little but reads 4x4 and 4x4 low....I do not hear the 4x4 HI engage however I can hear the clunk in 4x4 LO. Does not appear to be in 4x4 in HI but is engaged in Lo.
In manual hubs, truck engages in 4x4 high and low. Hear distinct engagement. Truck does fine driving
I use my 4x4 on occasion at the deer lease. I also run my 4x4 HI after every 5-7L oil change from the front of my subdivision to the back when I return from the change just to keep it "used".... its about 800 yards and I don't get over 25mph. This recent episode just showed up a short time ago and I've been putting it off.
The passenger front hub was replaced at 190K.....driver front hub still going strong as far as the bearings go. No problems switching from auto to manual at the hubs.
Did some initial testing and here is what I have found to date:
After thinking my AC hadn't or wouldn't switch to defrost, it did when I started jacking with the ESOF switch. It did however kick back down to the dash vents eventually. Now when turning the switch to 4x4 Hi, all I heard was a click and the axles after a minute were still free spinning. I placed it in neutral, pushed on brake, moved it to 4x4 Lo and heard the tell tale clunk....however the axle was still spinning freely......
Now when I do this in the street on a long straightaway in the subdivision, I can feel the truck in 4x4 Lo after the clunk above. However I feel no clunk/engagement in 4x4hi ....
My vacuum pump is also kicking on and working....and seemingly every time I start the truck. I would think this would not be necessarily good.
OK...some more tests......
Vehicle off....
Pulled solenoid lines off to hear a gushing of air coming out. Turned vehicle on, vacuum pump on, 4x4hi on and no vacuum felt from solenoid. AC goes to defrost. Hooked back up and AC went back to vents. 4x4 hi "click" but hubs spin freely.
Vehicle on...
Lines looked to have black particles coming off them and turned my hand jet black. No noticeable leaks/cracks but the lines will be replaced either way as they are rotting. Cut off inch on both sides just to see if that would solve problem. Nothing.
Pulled vacuum lines individually to add golf tee to check vacuum. Did driver side hub with tee first and there was no switching of AC. Replaced drivers side line and plugged passenger side hub with golf tee.... after 30 secs the AC switched to defrost.
Plugged both lines with golf tees and AC went to defrost.
Next some tests while moving...Switched hubs to manual on straightaway in subdivision. Switched ESOF to 4x4 Hi and the axle kicked in immediately. Same for 4x4 lo in neutral. Making sure I didn't turn in 4x4, I did this for a couple of straightaways in my subdivision with no problems. 4x4 seems fine when hubs are manually locked in.
Switched hubs back to auto and son of a gun, the 4x4 hi works....Did this numerous times turning 4x4 off when I had to turn. Got in a long straightaway and put it in 4x4 lo. It too worked. Drove it for 30-40 yards and switched out.
Here's the kicker...after switching it out of 4x4 low, it would not go back into 4x4Hi again.... I made another block and was unsuccessful getting it back into 4x4 hi. The switch would click and the light would come on but the axle did not lock in like earlier....
Replaced the rotting vacuum lines from frame to hub and had the same results. I am leaning toward a bad or intermittent vacuum solenoid/valve assembly, but haven't been able to confirm it. Any other thoughts? or tests to run?
Sorry I'm so long winded....I've just been do a ton of research and tests to get this fixed....thanks and I appreciate any feedback.
#2
05-28-2009, 05:20 PM
Hotshot
#3
05-28-2009, 07:43 PM
#4
05-28-2009, 08:09 PM
If the hub assy was replaced, was a new hub seal installed? I havn't been able to remove the hub or axle with out destroying the seal. It may look fine.....but wont hold a vacuum. I've been through all this PITA work to keep the auto hubs working on my 99.
You shouldn't hear a "clunk" when engaging 4Hi, only in/out of 4Lo. Sounds like the transfer case is shifting properly, but perhaps there is a vacuum leak in the hubs. Plug one hub vac line and engage 4wd. See if that hub locks. You can reach behind the tire and try to turn the u joint by hand. try this with both sides. See if it works. I use a vacuum gauge to monitor the engagement/disengagement when looking for leaks. Some one will know the proper readings for the two. (takes more vacuum to disengage then to engage).
I also had to replace the vacuum pulse solenoid. This made a big difference. You can PM me and I'll give you my fone# if I can be of more help. Not so good at writing.
You shouldn't hear a "clunk" when engaging 4Hi, only in/out of 4Lo. Sounds like the transfer case is shifting properly, but perhaps there is a vacuum leak in the hubs. Plug one hub vac line and engage 4wd. See if that hub locks. You can reach behind the tire and try to turn the u joint by hand. try this with both sides. See if it works. I use a vacuum gauge to monitor the engagement/disengagement when looking for leaks. Some one will know the proper readings for the two. (takes more vacuum to disengage then to engage).
I also had to replace the vacuum pulse solenoid. This made a big difference. You can PM me and I'll give you my fone# if I can be of more help. Not so good at writing.
#5
05-28-2009, 08:54 PM
I Plug one hub vac line and engage 4wd. See if that hub locks. You can reach behind the tire and try to turn the u joint by hand. try this with both sides. See if it works. I use a vacuum gauge to monitor the engagement/disengagement when looking for leaks. Some one will know the proper readings for the two. (takes more vacuum to disengage then to engage).
PM sent Tim. After I run these battery of other tests, I may give you a buzz tomorrow evening.
I guess in a nutshell is I am trying to rule out all the easily replaceable stuff before I start dropping money on the hubs and/or axles at this time.
#6
05-28-2009, 09:00 PM
#7
05-28-2009, 09:22 PM
Welcome to FTE! Sounds to me like you are on your way to solving the problem. I think the clunk you are hearing in 4low is just the transfer case and the hubs are not engaging. I would bet that hub you had replaced is the culprit, but I have not dealt with any issues on my ESOF other than sticky hubs on my X when I purchased it.
Let us know how it goes!
Let us know how it goes!
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#8
05-28-2009, 09:35 PM
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I had my passenger side hub replaced and the mechanic just forgot to add the yellow o-ring on the assembly. Not to mention they put the thrust washer on the wrong side and it ate into my knuckle seal.
Ed sells a ESOF reseal kit that includes everything to make sure your hubs hold the vacuum but if its the solenoid or the lines it wont be much help!
Th!nkPartsGuy/FTEPartsGuy
Ed sells a ESOF reseal kit that includes everything to make sure your hubs hold the vacuum but if its the solenoid or the lines it wont be much help!
Th!nkPartsGuy/FTEPartsGuy
#9
05-29-2009, 09:01 AM
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#10
05-29-2009, 09:02 AM
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#11
05-29-2009, 12:03 PM
#12
05-29-2009, 12:39 PM
#13
05-29-2009, 01:12 PM
New to the forum and thought I'd start off with a ESOF problem I've been having...
I drive a 2001 F350 CC 4x4 7.3l....I have read through a few searched threads and cannot get a definite answer....so I figured I'd give my scenario and see what the masses think.
In auto hubs.....I turn ESOF on....light delayed a little but reads 4x4 and 4x4 low....I do not hear the 4x4 HI engage however I can hear the clunk in 4x4 LO. Does not appear to be in 4x4 in HI but is engaged in Lo.
I don't here the clunk when putting it in 4x4 hi. The way this is set-up, you can't go into 4x4low without it being in 4x4 hi. Try this, crank your truck and put the shifter in neutral with the brake on. Turn the switch to 4x4 low, you will see the 4x4 high light come on then you will hear the clunk, then the 4x4 low light will come on.
In manual hubs, truck engages in 4x4 high and low. Hear distinct engagement. Truck does fine driving
The hubs have nothing to do with the transfer case engaging.
I use my 4x4 on occasion at the deer lease. I also run my 4x4 HI after every 5-7L oil change from the front of my subdivision to the back when I return from the change just to keep it "used".... its about 800 yards and I don't get over 25mph. This recent episode just showed up a short time ago and I've been putting it off.
If, when, I race someone, I have it in 4x4 high and go up to 90 mph in 4x4. Just don't engage 4x4 doing over 55 mph.
The passenger front hub was replaced at 190K.....driver front hub still going strong as far as the bearings go. No problems switching from auto to manual at the hubs.
Did some initial testing and here is what I have found to date:
After thinking my AC hadn't or wouldn't switch to defrost, it did when I started jacking with the ESOF switch. It did however kick back down to the dash vents eventually. Now when turning the switch to 4x4 Hi, all I heard was a click and the axles after a minute were still free spinning. I placed it in neutral, pushed on brake, moved it to 4x4 Lo and heard the tell tale clunk....however the axle was still spinning freely......
Again, you are hearing the clunk of the transfer case engaging into low.
Now when I do this in the street on a long straightaway in the subdivision, I can feel the truck in 4x4 Lo after the clunk above. However I feel no clunk/engagement in 4x4hi ....
Another, again, you will not hear the transfer case engage in 4x4 high.
My vacuum pump is also kicking on and working....and seemingly every time I start the truck. I would think this would not be necessarily good.
With the engine off, you will lose vacuum, and the pump should come on every time you turn the key to start the truck.
OK...some more tests......
Vehicle off....
Pulled solenoid lines off to hear a gushing of air coming out. Turned vehicle on, vacuum pump on, 4x4hi on and no vacuum felt from solenoid. AC goes to defrost. Hooked back up and AC went back to vents. 4x4 hi "click" but hubs spin freely.
If you pull the vacuum line off the solenoid, you will have a vacuum leak not pressured air. And without vacuum in the system, your air will default to the defrost setting, because you don't have vacuum to hold the door open.
Vehicle on...
Lines looked to have black particles coming off them and turned my hand jet black. No noticeable leaks/cracks but the lines will be replaced either way as they are rotting. Cut off inch on both sides just to see if that would solve problem. Nothing.
Pulled vacuum lines individually to add golf tee to check vacuum. Did driver side hub with tee first and there was no switching of AC. Replaced drivers side line and plugged passenger side hub with golf tee.... after 30 secs the AC switched to defrost.
Plugged both lines with golf tees and AC went to defrost.
Your golf tee may not be sealing good enough. Also, you can pull both vacuum lines off the hubs, but if you don't turn the switch to 4x4 giving signal for the seloniod to send vacuum to the front hubs, the vents will not go to the defrost.
Next some tests while moving...Switched hubs to manual on straightaway in subdivision. Switched ESOF to 4x4 Hi and the axle kicked in immediately. Same for 4x4 lo in neutral. Making sure I didn't turn in 4x4, I did this for a couple of straightaways in my subdivision with no problems. 4x4 seems fine when hubs are manually locked in.
Switched hubs back to auto and son of a gun, the 4x4 hi works....Did this numerous times turning 4x4 off when I had to turn. Got in a long straightaway and put it in 4x4 lo. It too worked. Drove it for 30-40 yards and switched out.
Here's the kicker...after switching it out of 4x4 low, it would not go back into 4x4Hi again.... I made another block and was unsuccessful getting it back into 4x4 hi. The switch would click and the light would come on but the axle did not lock in like earlier....
Replaced the rotting vacuum lines from frame to hub and had the same results. I am leaning toward a bad or intermittent vacuum solenoid/valve assembly, but haven't been able to confirm it. Any other thoughts? or tests to run?
Sorry I'm so long winded....I've just been do a ton of research and tests to get this fixed....thanks and I appreciate any feedback.
I drive a 2001 F350 CC 4x4 7.3l....I have read through a few searched threads and cannot get a definite answer....so I figured I'd give my scenario and see what the masses think.
In auto hubs.....I turn ESOF on....light delayed a little but reads 4x4 and 4x4 low....I do not hear the 4x4 HI engage however I can hear the clunk in 4x4 LO. Does not appear to be in 4x4 in HI but is engaged in Lo.
I don't here the clunk when putting it in 4x4 hi. The way this is set-up, you can't go into 4x4low without it being in 4x4 hi. Try this, crank your truck and put the shifter in neutral with the brake on. Turn the switch to 4x4 low, you will see the 4x4 high light come on then you will hear the clunk, then the 4x4 low light will come on.
In manual hubs, truck engages in 4x4 high and low. Hear distinct engagement. Truck does fine driving
The hubs have nothing to do with the transfer case engaging.
I use my 4x4 on occasion at the deer lease. I also run my 4x4 HI after every 5-7L oil change from the front of my subdivision to the back when I return from the change just to keep it "used".... its about 800 yards and I don't get over 25mph. This recent episode just showed up a short time ago and I've been putting it off.
If, when, I race someone, I have it in 4x4 high and go up to 90 mph in 4x4. Just don't engage 4x4 doing over 55 mph.
The passenger front hub was replaced at 190K.....driver front hub still going strong as far as the bearings go. No problems switching from auto to manual at the hubs.
Did some initial testing and here is what I have found to date:
After thinking my AC hadn't or wouldn't switch to defrost, it did when I started jacking with the ESOF switch. It did however kick back down to the dash vents eventually. Now when turning the switch to 4x4 Hi, all I heard was a click and the axles after a minute were still free spinning. I placed it in neutral, pushed on brake, moved it to 4x4 Lo and heard the tell tale clunk....however the axle was still spinning freely......
Again, you are hearing the clunk of the transfer case engaging into low.
Now when I do this in the street on a long straightaway in the subdivision, I can feel the truck in 4x4 Lo after the clunk above. However I feel no clunk/engagement in 4x4hi ....
Another, again, you will not hear the transfer case engage in 4x4 high.
My vacuum pump is also kicking on and working....and seemingly every time I start the truck. I would think this would not be necessarily good.
With the engine off, you will lose vacuum, and the pump should come on every time you turn the key to start the truck.
OK...some more tests......
Vehicle off....
Pulled solenoid lines off to hear a gushing of air coming out. Turned vehicle on, vacuum pump on, 4x4hi on and no vacuum felt from solenoid. AC goes to defrost. Hooked back up and AC went back to vents. 4x4 hi "click" but hubs spin freely.
If you pull the vacuum line off the solenoid, you will have a vacuum leak not pressured air. And without vacuum in the system, your air will default to the defrost setting, because you don't have vacuum to hold the door open.
Vehicle on...
Lines looked to have black particles coming off them and turned my hand jet black. No noticeable leaks/cracks but the lines will be replaced either way as they are rotting. Cut off inch on both sides just to see if that would solve problem. Nothing.
Pulled vacuum lines individually to add golf tee to check vacuum. Did driver side hub with tee first and there was no switching of AC. Replaced drivers side line and plugged passenger side hub with golf tee.... after 30 secs the AC switched to defrost.
Plugged both lines with golf tees and AC went to defrost.
Your golf tee may not be sealing good enough. Also, you can pull both vacuum lines off the hubs, but if you don't turn the switch to 4x4 giving signal for the seloniod to send vacuum to the front hubs, the vents will not go to the defrost.
Next some tests while moving...Switched hubs to manual on straightaway in subdivision. Switched ESOF to 4x4 Hi and the axle kicked in immediately. Same for 4x4 lo in neutral. Making sure I didn't turn in 4x4, I did this for a couple of straightaways in my subdivision with no problems. 4x4 seems fine when hubs are manually locked in.
Switched hubs back to auto and son of a gun, the 4x4 hi works....Did this numerous times turning 4x4 off when I had to turn. Got in a long straightaway and put it in 4x4 lo. It too worked. Drove it for 30-40 yards and switched out.
Here's the kicker...after switching it out of 4x4 low, it would not go back into 4x4Hi again.... I made another block and was unsuccessful getting it back into 4x4 hi. The switch would click and the light would come on but the axle did not lock in like earlier....
Replaced the rotting vacuum lines from frame to hub and had the same results. I am leaning toward a bad or intermittent vacuum solenoid/valve assembly, but haven't been able to confirm it. Any other thoughts? or tests to run?
Sorry I'm so long winded....I've just been do a ton of research and tests to get this fixed....thanks and I appreciate any feedback.
It's hard to know without being in the truck to see how you are testing this.
#14
05-29-2009, 02:18 PM
I don't here the clunk when putting it in 4x4 hi. The way this is set-up, you can't go into 4x4low without it being in 4x4 hi. Try this, crank your truck and put the shifter in neutral with the brake on. Turn the switch to 4x4 low, you will see the 4x4 high light come on then you will hear the clunk, then the 4x4 low light will come on.
Yes....this is the way it is...sorry for my miscommunication and lack of knowledge of the particulars.
I can however hear a difference between my 2x4 and my 4x4hi front when the hubs are on Manual. This is what I cannot hear when the hubs are in Auto.
Again sorry for my lack of knowledge of the particulars. The transfer case engages and the axles spin freely in AUTO. I am told they should not be able to spin freely. In manual hub they do not spin.
OK so the reservoir does not hold this air in? Good to know.
Your golf tee may not be sealing good enough. Also, you can pull both vacuum lines off the hubs, but if you don't turn the switch to 4x4 giving signal for the seloniod to send vacuum to the front hubs, the vents will not go to the defrost.[/quote]
I turned it to 4x4 high and the vents went to defrost with lines plugged. Golf tees were seated fine.
Thanks again miller.
#15
05-29-2009, 02:50 PM
What I don't understand, is, it will work sometimes and not work sometimes. Lets try something else, disconnect the electrical connection on the solenoid, turn it to 4x4 and see if the air defaults to defrost. By disconnecting the solenoid, it will not send vacuum to the front vacuum lines. If thats ok, then you have a hole/crack in one of the vacuum lines going to the hubs. The only way the air will go to the defrost is if there is a vacuum leak. This is a strange one, but I think it can be fixed.