Leaky front seal options? (5.9)

[Dapplecreek]

My 2002 Freightliner/Thomas has a Cummins 5.9 engine in it which (I found out today) is leaking from the front seal instead of the lines as we had hoped.

It loses a few tablespoons a day I would guess. I've been carrying around cardboard to toss under the front of the engine when I park.

What are my options? Or, I should say, what are your opinions about these options? Any other suggestions?

• Get a truck repair shop to replace it (any idea of cost?);
• Live with it - just top up the oil, and carry a lot of cardboard;
• Use stop-leak or some other magic potion (recommendations?);
• Something else?

Note that we will be selling the bus at the other end of the trip, but we may need to live in it for up to six months.

Thanks!

[EastCoastCB]

Originally Posted by Dapplecreek

My 2002 Freightliner/Thomas has a Cummins 5.9 engine in it which (I found out today) is leaking from the front seal instead of the lines as we had hoped.

It loses a few tablespoons a day I would guess. I've been carrying around cardboard to toss under the front of the engine when I park.

What are my options? Or, I should say, what are your opinions about these options? Any other suggestions?

• Get a truck repair shop to replace it (any idea of cost?);
• Live with it - just top up the oil, and carry a lot of cardboard;
• Use stop-leak or some other magic potion (recommendations?);
• Something else?

Note that we will be selling the bus at the other end of the trip, but we may need to live in it for up to six months.

Thanks!

Just keep it topped off.
DO NOT use "stop leak".

[Dapplecreek]

Originally Posted by EastCoastCB

Just keep it topped off.
DO NOT use "stop leak".

OK, question #1: how much oil does the crosshatched area on the dipstick represent? On a passenger car it represents a quart. Same here?

Question #2: my mechanic suggested the stop-leak. Why not use it? Not to cross you - just want to have something to say other than "a friend on the internet said..."

Thanks!

[EastCoastCB]

Originally Posted by Dapplecreek

OK, question #1: how much oil does the crosshatched area on the dipstick represent? On a passenger car it represents a quart. Same here?

Question #2: my mechanic suggested the stop-leak. Why not use it? Not to cross you - just want to have something to say other than "a friend on the internet said..."

Thanks!

Not sure on cummins but probably at least a half gallon. Check google.

I've never found band aids like "stop leak" to be anything but snake oil and they usually just plug up the internals. I ruined an engine with cooling system "stop leak" and learned my lesson.

Plenty of folks have leaky front covers on 5.9's. At least you're not leaking coolant like my 466 is!

[Dapplecreek]

Originally Posted by EastCoastCB

...they usually just plug up the internals. I ruined an engine with cooling system "stop leak" and learned my lesson.

I think that rather than cement for a coolant system, the stop leak for motor oil is often MEK (methyl-ethyl-ketone), which softens the seal rubber to help it seal better.

Edit: Lucas' stop leak for oil is all petroleum ("Distillates (petroleum), solvent-refined heavy naphthenic, 60-100%"). Not that I know what that means.

[EastCoastCB]

Originally Posted by Dapplecreek

I think that rather than cement for a coolant system, the stop leak for motor oil is often MEK (methyl-ethyl-ketone), which softens the seal rubber to help it seal better.

Edit: Lucas' stop leak for oil is all petroleum ("Distillates (petroleum), solvent-refined heavy naphthenic, 60-100%"). Not that I know what that means.

The coolant stuff wasn't cement.

[Dapplecreek]

Originally Posted by EastCoastCB

The coolant stuff wasn't cement.

Apologies: I've used stuff before that kinda turned into cement. The distinction I was trying to make was that the coolant stuff may try to fill holes while the oil stuff may try to soften rubber. Lucas' pitch says it fills worn spaces, so it's doing both.

[joeblack5]

Not sure that I understand the front seal leak. The oil level is below the seals. So ,without the engine running, the leak should stop after a couple of days when the volume between the seal and the bearing has leaked out. While running and on the road it might leak more. May be you found the reason while you have so little rust ... just joking. Thanks for hanging out while I was driving back from West Jefferson.
Hope you made progress on your planning.

good luck, j

[Dapplecreek]

Originally Posted by joeblack5

Not sure that I understand the front seal leak. The oil level is below the seals. So ,without the engine running, the leak should stop after a couple of days when the volume between the seal and the bearing has leaked out. While running and on the road it might leak more.

That's a keen observation: now that I think of it, I do get a fair number of drips after stopping (and presumably while running), but after a day or several I don't see the volume I would expect were it to be dripping constantly at that rate.

Originally Posted by joeblack5

May be you found the reason while you have so little rust...

I'll take it!

[Elliot Naess]

An other place the 5.9 often leaks is the tappet cover on the left side of the block. At least on the 12 valve -- I just realized 2002 is a 24 valve, and I'm not sure about that one.

[Dapplecreek]

Originally Posted by Elliot Naess

An other place the 5.9 often leaks is the tappet cover on the left side of the block. At least on the 12 valve -- I just realized 2002 is a 24 valve, and I'm not sure about that one.

Yeah, and you have to pull the injector pump to replace that plate, too, I believe. But my mechanic (for whom I have great respect) says the leak is from the front seal and that it's beyond his ability/tools/facilities. Sigh...

[brokedown]

re: hash area on the dipstick, my T444E has about a gallon between the top and bottom of it...

[cadillackid]

the tappet cover was my first guess as to the nost likely place of a leak... now.. stop leak.. yeah im the unpopular one on this.. with somewhat hardened seals,. oil stop leak can soften them and make them last for a good while longer.. seems to never completely stop the ;eaks but does slow them down..



ive known people to run lucas stop leak (not lucas oil conditioner or STP) for long periods of time without issues.. I run it in my DEV bus.. hasnt seem to hurt anything in the 20k or so miles ive driven that bus.. I never had bad leaks in that engine.. but the drops on the ground.. not even tablespoons.. just drops.. and it definitely slowed them way way down..



if you are losing tablespoons of oil you'll have BIG SPOTS on the ground under your bus.. not sure on the cummins but on my bus, the add-cold line is 2 quarts low.. out of 20 so it doesnt hurt to run unless you are going below add. over-filling a diesel can throw oil on the ground through the draft tube...

-Christopher

[Dapplecreek]

Thanks, all! Looks like my mechanic put in Lucas Stop-Leak before talking to me: I'll let you know how it works out.

[cadillackid]

Originally Posted by Dapplecreek

Thanks, all! Looks like my mechanic put in Lucas Stop-Leak before talking to me: I'll let you know how it works out.

Lucas stop leak requires a minimum of 2 quarts in a bus... 2 is a good starting point.. but if its that tappet cover(I dont know exactly which motor you have?) then the lucas isnt likely to help.. theres a ton of oil under some mild crankcase pressure in that area
-Christopher

[Dapplecreek]

Originally Posted by cadillackid

...but if its that tappet cover(I dont know exactly which motor you have?) then the lucas isnt likely to help...
-Christopher

2002 Cummins 24v, not the Brazilian thin-wall.

But the mechanic was solid on the location of the leak: front seal.

Thanks, though! Good info for other visitors, too.

[Trailer2]

The front seal on these engines is Teflon. It is not like a normal rubber lip seal. The crank probably has a small groove where the seal rides. A new seal will come with an install tool to make the new seal ride in a different spot on the crank. I would just fix the seal. It is not that bad.

[golfersmurf57]

Originally Posted by Dapplecreek

My 2002 Freightliner/Thomas has a Cummins 5.9 engine in it which (I found out today) is leaking from the front seal instead of the lines as we had hoped.

It loses a few tablespoons a day I would guess. I've been carrying around cardboard to toss under the front of the engine when I park.

What are my options? Or, I should say, what are your opinions about these options? Any other suggestions?

• Get a truck repair shop to replace it (any idea of cost?);
• Live with it - just top up the oil, and carry a lot of cardboard;
• Use stop-leak or some other magic potion (recommendations?);
• Something else?

Note that we will be selling the bus at the other end of the trip, but we may need to live in it for up to six months.

Thanks!

Stop leak for oils is usually some solvent based compound that softens and swells the rubber lip on the seal. If the seal is badly deteriorated, itit can tear causing a worse leak than you had. On RE bus its a simple job. Pull the bumper remove belts and balancer then front cover. FE bus means radiator usually gets pulled too. If you don't have a means to handle the radiator, pay someone who does.

[Mr4btTahoe]

Dont use stop leak...


Its not a bad fix. Pull the belt, balancer, and front cover. Knock the front seal out of the cover. Install a new front seal in the cover with a wear sleeve (speedi sleeve) on the crank snout. Re-install the front cover with the seal installer sleeve. Re-Install the balancer and belt. It's pretty straight forward.



If you have to pull the radiator.. you'll need another set of hands or a hoist more then likely.

[Elliot Naess]

Guys... I'm stumbling in here without reading the previous posts. Not feeling so good right now.. But this popped up on my screen....
What exactly does it take to remove the balancer/pully?

I've done several on cars, and I have a puller for that. is it the same on the 5.9? Just need a larger puller?