The Diesel Stop banner

1 - 9 of 9 Posts

·
Registered
Joined
·
264 Posts
Discussion Starter #1 (Edited)
I replaced main axle seals, yellow O Rings, and hub O Rings when I did my ball joints about a year ago. ESOF has worked fine since then. However, since I recently noticed fluid dripping from the axle shaft, I suppose I damaged one on the axle inner seals when I did the ball joints.

I had a shop replace the inner seals and now neither of my hubs will hold vacuum. The shop says that all of the seals looked new (which they were) so they did not replace any of them. Please don't bother to ask me about the other ESOF system components. I disconnected the vac hose behind the wheel and used my Mighty Vac and a 3 ft piece of hose to apply vacuum directly to the hub. The problem IS the hubs not holding vacuum.

Any ideas on what the likely cause off this problem might be? I sure hope its not the main axle seals (the big, expensive, hard to replace ones!)

Thanks
 

·
Registered
Joined
·
4,729 Posts
The large seal behind the wheel bearing in the steering knuckle is easily damaged during disassembly ESPECIALLY if the seal has been in the vehicle for any length of time and a lot of effort is required to get the axle out. Additionally, when replacing the seals a special installation tool is required to prevent damage THAT ALSO IS REQUIRED TO SEAT THE SEAL IN THE BACK OF THE KNUCKE when the axle shafts are put back into the axle. The tool not only prevents damaging the seal but it also sets it to the proper depth.

Share this diagnostic tip with your "mechanic:"

A great way to diagnose leaks in the pulse vac system is to employ an emissions smoke testing machine: a tester that produces smoke under calibrated pressure for diagnosing leaks in evaporative emissions systems on gasoline vehicles. Simply place the smoke tester supply hose to the vacuum supply line going to the axle and wait a minute or two. If there is a leak, smoke will be visible which not only verifies that a leak exists it also helps locate the leak. It is important to do this with the front wheels off the ground so that the wheels can be rotated and the steering turned side-to-side to simulate normal movement of the seal.


Good Luck!
 

·
Registered
Joined
·
264 Posts
Discussion Starter #3
Doc,

Thanks............great suggestion.
 

·
Registered
Joined
·
17 Posts
Same Issue....But Different

Been a long time sine I've been on this forum....a few years. Well, at least as far as being logged in. I've checked threads from time to time. I guess I've not had many issues. Anyhow, Bringing this thread back up to see if there was resolution since I have a very similar problem. Except I did have a bad vacuum/knuckle seal after the hubs remained locked in for the last year due to a pulse vacuum module being bad and me being to lazy to troubleshoot. Anyhow, trouble shot the system and found it bad and replaced that and now the passenger side works fine, but not the driver's side. Pulled the driver's side apart and found vacuum seal destroyed. Replaced the seal and metal dust cover. Pressed on with the homemade tool (1-1/2" pipe and flange plate) Went on fine, seated at the correct depth as far as where the old one was. Then replaced the hub o-ring and the locker o-ring Still not holding vacuum (heard a slight hiss in the hub when pulling vacuum when gauge would hit 5). Pulled hub back out applied thin coat of a #2 grease to the new hub o-ring instead of the white lithium I initially used and re-installed the hub. Vacuum went to about 10 but them bled back down to 5 and eventually bled down slowly from there. So i think it has to be the new vacuum seal. I must have damaged it when installing back into the knuckle joint. I installed it as follows: Slid it it in by hand until it reached the slight ridge in the housing and would go no further by hand. Then I installed the hub and put the nuts on the hub studs. Tightened them evenly by 2 to 3 turns each all the around until the hub seated. Could that have damaged the seal maybe by possibly pushing the inner part of the seal and dragging the outer portion? I did not lube the seal as I did not see anyone that had done that when they installed theirs on any of the sites I visited. Maybe this damaged it, I just don't know. Could the hub itself be the problem? Kind of at a loss at this time. Thanks for your time.
 

·
Registered
Joined
·
264 Posts
Discussion Starter #5 (Edited)
After LOTS of frustration, expense, greasy hands, 68 yr old busted knuckles, and cussing, I finally succumbed and FIXED my problems by installing inexpensive LIFE WARRANTY Warn manual hubs. NO MORE worry about the crummy vacuum components (plugged the lines/s), and now when I lock the hubs I don't WONDER but I KNOW they are locked!

Now I just need to figure out how to lock both axles to no slip while in 4WD! This is because using 4WD on a slick / muddy surface with my almost 10000 lb truck with 80 lbs of tire air pressure and All Terrain tire tread is almost like driving on ice!......especially when towing even a very small trailer....like for my ATV! I would be SOL if it were not for my receiver mounted 8K lbs. Warn winch that mounts on either end of my truck. But it sure is a PITA to get that out and hook it up etc.
 

·
Registered
Joined
·
17 Posts
I have thought about switching to the Warn lockers, but for now that is a last resort. Although glad you found your solution, and that might very well be mine soon. But the one side is working fine and I just would rather not spend that cash just yet since I already have $100 in seals and such in this job for one side. But time will tell. I have some grease that is piled up outside the actual hub bearings which should be sealed, so I'm wondering if the hub itself could be causing it, although there is no slop and the operation is smooth. Or I could've just damaged the vacuum seal going in. Just not sure at this point....I'm hard headed, so I will continue to try to get it right, at least for a while. Thanks for the reply!
 

·
Registered
Joined
·
250 Posts
After LOTS of frustration, expense, greasy hands, 68 yr old busted knuckles, and cussing, I finally succumbed and FIXED my problems by installing inexpensive LIFE WARRANTY Warn manual hubs. NO MORE worry about the crummy vacuum components (plugged the lines/s), and now when I lock the hubs I don't WONDER but I KNOW they are locked!

Now I just need to figure out how to lock both axles to no slip while in 4WD! This is because using 4WD on a slick / muddy surface with my almost 10000 lb truck with 80 lbs of tire air pressure and All Terrain tire tread is almost like driving on ice!......especially when towing even a very small trailer....like for my ATV! I would be SOL if it were not for my receiver mounted 8K lbs. Warn winch that mounts on either end of my truck. But it sure is a PITA to get that out and hook it up etc.
I was just about to suggest switching to warn hubs. Saves alot of troubleshooting and especially keeps you from freezing your but off when the heater vents wont work due to a vacuum leak in the dead of winter.
 

·
Registered
Joined
·
1 Posts
Bringing up an old thread again. It's been a long time since I posted (I couldn't remember my login so who knows) but I have another 6.0 and thought what the heck. I love all of the great information on the board.

Anywho, I too have a vacuum leak at both wheels and would prefer to switch to manual hubs, but.... if I have to replace the seals I might as well go all out and just get the ESOF working as it should.

My question: is it absolutely necessary to replace that vacuum seal in each hub? The cost of buying that kit would go a long way toward manual hubs. What could be harmed if I don't replace those seals?

Thanks for any help!
 

·
Registered
Joined
·
4,729 Posts
Well if you KNOW that you have vacuum leaks at the hubs then YES you have to replace the seals. If you don't replace the seals USUALLY the only harm is that the system does not work. You do realize that your "auto hubs" have a lock position (?) so if the lock knobs are not seized and move freely then realistically you already have working manual hubs.
 
1 - 9 of 9 Posts
Top