New York bound with wheel seal woes - plus VMSPC screen shot

[Brian Diehl]

The family and I are now in the Niagara Falls area of New York after 1100+ miles.  The bus has been running great with one exception - passenger front wheel seal.  This wheel seal is driving me crazy.  A year + ago a wheel seal that had a decade on it since last being replaced started leaking.  I have now replaced it twice since then.  This latest seal was put on last fall and then the bus was parked for the winter.  The seal did not leak a drop for the past 6 months while parked.  Then, on the way east it started leaking again.  Overnight when the wheel cools off the seal will not leak at all.  Then during the day when the hub gets up to temperature, about 100 degrees, it will start to leak.  It is not leaking a lot, just enough to be annoying.  It appears to be leaking around the outer edge of the seal where it is pressed into the hub.  Now that I look back at the prior three failures they all seam to happen only when the hub is warm.  I'm at a loss now.  I know if I simply put a new one on it will leak as well.  What should I be looking for?  Is there any other sort of seal compound I can put on the seal and/or hub when I install it to try and keep it dry?  Or, should I just convert over to grease?  I don't think my technique is necessarily the problem as I have 1 drive axle and two tag axle hub seals I've replaced that are leak free.  However, you never know.

And just for grins, here is a screen shot from my VMSPC program while running down the road today.

[Lostranger]

I'd almost bet that the problem is wheel bearing adjustment. Years ago I had the same problem with an LN 750 Ford truck. I changed the seal twice, but it kept leaking. Fortunately, a friend who was an experienced truck mechanic heard me mention it and offered to take a look. I cannot give a formula for how he decided it was tight enough — over tight does not work — but when he got through, the seal never leaked. That may be something you could find through internet research.

As I read back over this post, I remember that he left the wheel in place and jacked up that corner. After removing the hub cover and the lock nut, he spun the wheel in the direction to tighten the adjuster nut and jammed a long punch between the spinning hub and the nut. He commented that this method gave him a better feel for how tight the nut was than he got using a socket and breaker bar. If I were doing the job, I believe I would use a socket and bar, but I would spin the wheel by hand as I tightened the nut. That seems to give a more accurate feel for how tight the adjustment is.

I had bought a third seal, but he looked at the one in the hub and reused it.

Good luck with the problem. Let us know what works.

Jim

[Dave5Cs]

If you have done all of them and this same one leaks every time, Could it be the Hub seat or race and not the seal at all?

Dave5Cs

[eagle19952]

"he spun the wheel in the direction to tighten the adjuster nut and jammed a long punch between the spinning hub and the nut. He commented that this method gave him a better feel for how tight the nut was than he got using a socket and breaker bar".

Exactly how I was taught to do it..cept I always used cold chisels...

Infact i was told by a fellow that worked for Timken that if you look at a bearing in rotation, you will see each individual roller rotating, when each roller is turning uniformly/synchronous  in relation to each other, that is good enough. tighten as far as necsasary to facilitate the lock and your done. Did many (over 40 years) this way and never lost a one, bearing or seal.

Were I you and my seal was leaking from the outer circumference , and this has happened more than once, I would install the next one with loctite bearing set compound.

Loctite ® 609™ is a low viscosity, rapid-curing anaerobic adhesive that augments the strength of press fit assemblies or slip fit assemblies up to 0.005"in diameter. Adds up to 3,000 psi holding power. Recommended for parts that will need subsequent dismantling, i.e., retention of bearings onto shafts and into housings.

[biff]

I would make sure the vent hole in the rubber plug is not pluged up or painted over.

[gumpy]

Seal leakage is typically caused by improperly adjusted bearings, as indicated above. 

You could put some RTV around the seal when you put it in. Make sure the seat and seal are completely dry and only use a thin coat on the seal itself.

[gumpy]

Oh, and about your VMSPC thingy.... Holy crap! Talk about distracted driving!

[eagle19952]

You could put some RTV around the seal when you put it in.

i used to walk around my shop and fill a five gallon bucket with tubes of silicone...i hate it. my mechanics bought it, i paid for it and i threw it away. rtv is for bath tubs...it is an adhesive.

[bandsaw]

Get a dial indicator and check the end play of the bearing.  With everything at ambient temperature the end play should be 0.001 to 0.002 inches.  I spend several hours researching this. The best bearing life is achieved with a slight preload (no end play). Putting more preload will shorten the life of the bearing.  It is difficult to measure how much preload is on the bearing. That is why they recommend the 0.001 inch of end play.

Once the seal is pressed in I smear The Right Stuff from Permatex around the outer edge of the seal. In my opinion this goop is far superior to RTV.

Milo

[Boomer]

Hey Brian, do you ever get CE or SE lights with intake air temps that high?  Cummins engineering told me that up in that area and you will get a ramp down or light, it's happened on my ISM before.  Correction:  that's at 170 deg. not 70 deg.

[luvrbus]

Triseal premium wheel seals will stop those leaks that keep coming back fwiw I have always used SKF Scotseal till I tried the Triseal big difference and easy to install 

[eagle19952]

Get a dial indicator and check the end play of the bearing.  With everything at ambient temperature the end play should be 0.001 to 0.002 inches.  

Milo

92$ jobber price...never knew they made such a deal...
5. The dial indicator shows the amount of bearing end play. It should read between 0.001' and 0.005' (in accordance with TMC Recommended Guidelines).




http://triseal.vayanet.net/Products/data/comersus_viewItem.asp?idProduct=9

[Tom Y]

Brian, Which way are you heading? East?

[Brian Diehl]

If you have done all of them and this same one leaks every time, Could it be the Hub seat or race and not the seal at all?

Dave5Cs

Dave - I'm wondering the same thing as well.  I'm not sure how I could tell for sure, that is the problem.

[Brian Diehl]

I'd almost bet that the problem is wheel bearing adjustment. Years ago I had the same problem with an LN 750 Ford truck. I changed the seal twice, but it kept leaking. Fortunately, a friend who was an experienced truck mechanic heard me mention it and offered to take a look. I cannot give a formula for how he decided it was tight enough — over tight does not work — but when he got through, the seal never leaked. That may be something you could find through internet research.

As I read back over this post, I remember that he left the wheel in place and jacked up that corner. After removing the hub cover and the lock nut, he spun the wheel in the direction to tighten the adjuster nut and jammed a long punch between the spinning hub and the nut. He commented that this method gave him a better feel for how tight the nut was than he got using a socket and breaker bar. If I were doing the job, I believe I would use a socket and bar, but I would spin the wheel by hand as I tightened the nut. That seems to give a more accurate feel for how tight the adjustment is.

I had bought a third seal, but he looked at the one in the hub and reused it.

Good luck with the problem. Let us know what works.

Jim

Jim - I'll jack it up when I get a chance and see what might be going on.  I'd sure like to have that $100 end play indicator to be able to measure end play directly.