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Topic: Front Wheel Bearing/Hub Seals, 2001 U320 (Read 1741 times) previous topic - next topic

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #25 –
Silicone, be it o-ring, sheet gasket mat'l or caulk is not a proper sealant for oil.
Below is an elastomer/chemical compatibility chart.
John

http://www.cmrubber.com/pdf/elastomer_compatibility_chart.pdf

John and Stacey Smith
Motorcade NO: 11973
1997 U295 CSGI 40'..Build No. 5036     
920 Watts on the roof..CAT Power w/fuel Inj. Programmer
2021 GMC Sierra AT4 1500
EX..2015 Jeep Wrangler Sahara
Ex 1990 U280 RSAI 36'..Build No. 3638

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #26 –
I think the proper use for silicone with a gasket is intended just to hold the gasket in place not to be the gasket.The Stemco kits I
bought for my hubs did not have the gasket,that was a seperate part that can be found at truck parts stores.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #28 –
RTV sealant is Silicone.  Per Permatex it is compatable with acids and alkys but not oil. 

Permatex® Clear RTV Silicone Adhesive Sealant - Permatex

For the wheel bearing hub gaskets I coat with Permatex "  Permatex® Form-A-Gasket® No. 2 Sealant - Permatex  Non hardening, pliable sealant.  Enhances gasket seal, especially on gaskets that are sealing porous (soft metals) and under low bolt torque pressure like the hub seals.
'87 40' Grand Villa 4000 SBID ORED
CAT 3208TA 300Hp driving MT647, PacBrake
Unkown watts Solar
'17 Conti's HSR2 10-22.5
Cove, Texas
Previous: '76 to '16,  5' 10", 0.1Hp, hauling 85lb BackPack shod on Keen Boots

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #30 –
I use this;  RTV Sealant | ACDelco

Gotcha,  that's not silicone.  Looks good.
'87 40' Grand Villa 4000 SBID ORED
CAT 3208TA 300Hp driving MT647, PacBrake
Unkown watts Solar
'17 Conti's HSR2 10-22.5
Cove, Texas
Previous: '76 to '16,  5' 10", 0.1Hp, hauling 85lb BackPack shod on Keen Boots

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #31 –
Interesting, I always equated "RTV" with silicone.  Learned today that RTV means room temperature vulcanizing. 

Gettin' schooled!  ^.^d
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #32 –
When I changed the oil in our hubs day before yesterday, I found a sizable rag inside the driver side steer hubcap.  It was apparently there to absorb seepage from the hub, and that hub was the only one of the 4 that was overfilled.  I removed the rag, and filled with new oil to the correct level.  So far no seepage after about 125 miles.
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #33 –
I have always installed new hub caps dry.  I have done several over the years and have never had any leakage.  Several mechanics and Kelly Truck here in Nacogdoches told me to install the gaskets dry and tighten to 14-16 ft. lb. torque.  When I first looked at the 04 I  just bought from MOT it had oil streaks on the right front wheel before they cleaned it up.  When I got it home I pulled the wheel cover and someone had put sealant on the gasket.  After pumping the remaining oil out I bought a new hub cap from Kelly Truck and installed it and not had any problem since.  On several other hubs I have replaced over the years I have never had any problem leaking after installing them dry.  The left front wheel was not leaking and did not have sealant. I did pump the old oil out and replaced it.  I have always used Lucas Hub oil, since that is what it is made for.
Chappell & Mary
36' 2004 Foretravel U270 build #6273

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #34 –
Think the hub cap Mark is talking about is the chrome piece covering the hub.
96 U270 BUILD 4810
85 380SL
Drummonds TN.
 

Re: Front Wheel Bearing/Hub Seals, 2001 U320

Reply #35 –
The red caps shrink over time due to heat cycles. They don't leak much, but leave the streaks. I keep paper towels in the caps of my crane and when I see they are getting oily I change the little red cap. I can actually wiggle the cap when they shrink. I can't have the streaks showing because of Highway patrol inspections. They would think the axle seal or bearing was bad. The right one in my coach was loose when I purchased it. Because I changed both inner seals I put new plugs in and don't use the paper towels so I can monitor any leakage. There is a very small hole in the plugs to let the pressure out, if they somehow get plugged the cap will leak also. Two years latter the hubs are still dry.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
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