Oil Leaking from inside front drivers side wheel

[John44]

I have an 06 Alfa with Freightliner chassis. After completing trip to Texas a couple of weeks ago I now have observed an oil leak inside the drivers side front wheel. It appears to be heavy weight oil and is draining from inside of wheel down tire to pad. There is a coat of oil around the inside of the wheel indicating that it was slinging during at least the last portion of my trip. The draining didn't show on the pad until being parked for about 2 weeks. I haven't experienced any seal issues like this on anything before, so I am somewhat lost about how to trouble shoot the issue. I think there is a way to observe the fluid level, but I have never done so. I wonder if it is possible to refill the fluid and then drive the unit to a service center about 40 mile away?

Any advise on how to approach this issue would be appreciated.

Thanks,
John

[Martind4]

On our coach there is a chrome baby moon hubcap that covers the front axle. With the hubcap is removed you will see a small rubber cap in the very center of the wheel that covers a sight glass. Remove the rubber cap (plug) to see the oil level inside. The oil level is supposed to be about halfway up the glass.

If the level is low, you might have to rotate the tire to get the fill spout to the top. Use SAE 90W oil.

A small oil leak can look pretty serious, but if the oil level is close to the middle of the sightglass I wouldn't hesitate to drive the rig 40 miles to a repair shop.

Hope this helps.

[John44]

Thank you Martind4, I thought there was a sight glass there somewhere but wasn't sure where the access point was. I will give it a check this morning.

[FleetMan]

It sounds like your inner oil seal has failed. You probably have oil on the brake shoes and will probably have to replace them. Also, depending on how much oil has leaked, you could ruin the front wheel bearings - worst case, overheated bearings welding themselves to the spindle. This problem should be repaired before you attempt any daylong type driving. You can top off the oil in the hub and drive it to a repair facility safely with the understanding the braking action at that wheel may not be balanced with the opposite brake. Many people get spooked when they experience a seal failure on an oil filled hub and revert to repacking the bearings with grease. The benefit of grease is no more fear of oil getting on the brake shoes - the trade off is repacking the bearings on a periodic basis. Best case scenario, the seal failed after you parked and the oil just ran down onto the drum and out onto the tire and ground and did not contaminate the brake lining.

[John44]

Just removed the cap and found the level really low. It appears that the hub drained quite a bit after I parked. The draining did occur on the inside of the hub, no evidence of oil on the outer hub. The visible bearing seems ok, but I don't know for sure what the inside looks like. I think I am going to call one of the local truck centers and see if they will come pull the wheel and make the necessary repairs without moving the unit. No need risking further damage if the leak is that bad. As "Fleetman" suggested, I suppose the brake pads are going to be in need of replacement as well. I would imagine the other seals will be needing to be inspected too. If that one went bad I wouldn't be surprised if another was on the verge also.

Thank you guys for the quick responses, instructions and suggestions.

[Vintage]

I just replaced the seal on my front wheel. I noticed the drip on the inside also.
I took it to Gibbs Truck center and they did the job while I waited. Took about 45 minutes and cost $145 including the new seal and oil. The lower shoe had some on it but it washed right off with some brakekleen.

[OneRVer]

Quote:

Originally Posted by Martind4 On our coach there is a chrome baby moon hubcap that covers the front axle. With the hubcap is removed you will see a small rubber cap in the very center of the wheel that covers a sight glass. Remove the rubber cap (plug) to see the oil level inside. The oil level is supposed to be about halfway up the glass. If the level is low, you might have to rotate the tire to get the fill spout to the top. Use SAE 90W oil. A small oil leak can look pretty serious, but if the oil level is close to the middle of the sightglass I wouldn't hesitate to drive the rig 40 miles to a repair shop. Hope this helps.

Martin, What do you mean by "rotate the tire to get the fill spout to the top"? I just changed my oil and just poured the new oil into the hole to the full mark. Am I missing something.

[Vintage]

You don't need to remove the rubber plug to check the level. You can see it clearly on the side of the sight glass. There is a line that indicates the correct level.

You need to rotate the side plug of you want to drain the bearing. You can just carefully remove the rubber plug i the center if you just want to add some oil. Lucas makes "Hub Oil"

If you are low on oil it is not evaporating. it is leaking and it will get on your brake lining if there is a lot of leaking.

My coach sat for three years before I bought it. The seal got gummy and whenever it was rotated the oil seeped past the gummy part of the seal/hub contact.

[Martind4]

I didn't mean to confuse anyone but that's what I get for trusting my memory. It's been almost a year since I checked the hub oil. Our sightglass is pretty old and its difficult to see the oil level without a really bright light, so I found it easier to pull the rubber plug in the center. If I ever need to fill, I was going do it thru the fill/drain plug shown at the 4 o'clock position in the picture. That would need to be rotated to the 12 o'clock position or thereabouts. I never thought about adding at the rubber plug. I guess either way would work.

[OneRVer]

I'll be, I don't have a drain port, at least on that I can see. I change my oil about every two years and I have to siphon my old oil out. Now I understand what you are talking about. Thanks.

[John44]

Just returned from shop. New seal, cleaned brake pads, adjusted brakes on both front wheels. Parts and 2 hours labor. Took the guy a little longer than that mostly as a result of shop congestion. Any way I was in and out without and further delay and the shop total was $229.00.

Just a sharing based on some of the other comments on this thread. The shop guy filled the hub thru the rubber seal hole. He allowed the oil to settle several times before replacing the plug. He also made sure the vent hole in the plug was clear. He said that if the hole is clogged it can cause pressure to build when oil heats and rupture the real seal.

I'm happy again...

[Vintage]

Congrats!