Cat water pump bearing

[flagstickfrank]

I have a 2000 Itasca Horizon DP with 3126B Cat 300 engine. I have been very happy with the coach and engine/trans with one exception. The water pump bearing on the engine has a grease serk (sp) that is out of reach for anyone but a monkey. I have reached it by removing the bed and engine cover but surely someone has an easier method? I would like to lube it every 3,000 miles but it's a pain.

[wolfe10]

No need to remove the radiator to install an extension. The only exception is if the coach builder left you NO access to the top front of the engine.

Again, make POSITIVE that all air is purged from the extension so you know that those two little squirts of grease actually put two little squirts of grease into the bearing area.

Access from above and below is all you need to install one.

[flagstickfrank]

Very good information, just what I need to determine my next step. This coach has 120,000 miles on the original bearing and wasn't greased for the first 40K because of owner ignorance. I only learned of this problem after I joined GS and started reading the forums. (Thanks to all for that)
I plan to install the flex line that was mentioned before, does anyone have knowledge that it can be installed from up above/below or does the radiator have to removed?

[RayChez]

What I done was to get a specially made grease hose long enough to where I can reach it from the passenger side of the engine. I believe it is around 36" long for the grease gun, not to have hanging on the side of engine. I made sure all the air was out of the hose and had pressure before I even attempted to grease it. Still not like if it was right in front of you to get serviced, but it saves me the trouble of removing the mattress and long screws that hold the engine box lid down. I lube it once a year and I only give it about four squirts of grease. Actually if it wasn't for a big CAC hose on the way, it would be much easier, but my arms are long enough to reach over the hose and make sure to press down hard on the connection to the fitting and grease gun head.

[sailor_lou]

I agree the number of sealed bearing failures is probably extremely low when considering the vast number of engines in service. I also believe that an undetectable catastrophic failure of the bearing is extremely rare (if at all), so a maintenance check as noted above is the key to preventing a roadside disaster.

In my case, I check all the accessory bearings (water pump, alternator, A/C compressor, fan pulley, etc). for both smooth operation and excessive play every spring when I take my MOHO out of winter storage. So far, no detectable play in the fan bearing, but it did once identify the start of a bearing problem in the alternator. By performing this simple check I eliminated a roadside breakdown, with the potential of collateral damage, to a pretty easy repair which I performed in my driveway.

I worked as a power plant engineer for 30+ years and another good practice, which is often performed in the commercial/manufacturing industries, is to loosen the tension on the belt(s) when equipment is placed into long term storage. It is not only good for the belt, but eliminates the constant one direction pull on the engine accessory components. It's a pretty easy thing to do by simply moving the tensioner and slipping the belt off any one of the pulleys and reduces the load on all the components.

Good luck and safe (uneventful) travels to all.

Lou
05 Travel Supreme Envoy
CAT C7

[FIRE_UP]

But in general reliability is still very good.

Without a doubt, very true. As you sort of stated Brett, we only read of issues "posted" on here and a couple of other forums. What about the zillions of CATS and other powered coaches that are running all over this planet that have had zero issues!!
Scott

[wolfe10]

Moisheh,

Actually it was because of failures of the greasable bearing (not being greased) that Caterpillar switched to the sealed bearings. I still stand by my good to bad list with greasable being at both top and bottom depending on level of maintenance.

I completely agree that an "engine in back" has unique challenges with "under hood" temperature being one of them. Affects several on-engine items like alternator, water pump, fan hub, some fuel system components, etc.

But in general reliability is still very good.

[moisheh]

duplicate post

[moisheh]

Normally I would bow to Wolfe's professional knowledge. But the Cat C7 in a rear engine MH does have some problems that C7's do not have in other applications. That bearing is one of them. I am convinced that it is due to a heat retention in that area. I have read Fire Fighter forums and do not ever remember seeing that problem with the C7. Some RV owners have even posted the part #'s for changing over to a greasable bearing. I have also noticed that it is rare to see someone posting about the bearing disintegrating in a Pre C7 Cat ( greasable). When we had a MH with a C7 I carried a spare bearing! Never had to use it as we sold that unit within 12 months.

Moisheh

[wolfe10]

Scott,

Very hard to know how much of an issue it is. The internet is probably the absolute WORSE place to gather statistical data. Only those with issues ever say anything. And, if 5 people report a failure here, there may be 10,000 with the same engine and no problems.

If I had a coach with either the sealed or greasable bearing I would treat it just like most everything else on the engine. When I do the annual inspection, oil and filter change, etc I check them for play. No different than a water pump or any other component.

Yes, I have seen posts-- it just HAPPENED! But, I view it as VERY rare for a bearing to go from perfect to denigrated without going through a process of degradation-- where it has play, makes noise, belt slips, etc. Said another way, even doing a walkaround of the coach with engine running (a good idea on ANY coach, a bearing going bad should be noticeable. Same for water pump, alternator, power steering pump...... Gas or diesel.

[FIRE_UP]

wolfe10 wrote:

moisheh wrote:
NEVER replace that bearing with a sealed bearing. Contrary to some posts the C7 has a sealed bearing and a short life. Probably due to all the heat in that area. If that bearing lets go you will have a huge repair bill!

Moisheh

Let me expand a little, since Caterpillar has both sealed and greasable hubs available.

From BEST to WORST:

Greasable bearing that YOU DO GREASE.

Sealed bearing

Greasable bearing that YOU DO NOT GREASE.

Brett,
Just wondering. Since you see and know of, way more failures of the sealed bearings on CAT C-7s (like mine) than all of us put together, how do you compare that particular sealed bearing, with just about any other non-lubeable bearing on any accessory, on not only diesel engines but gas ones too? In other words, there's zillions of non-lubed bearings on zillions of accessories, i.e. water pumps, alternators, tensioners, idler pulleys, and more that have upwards and more of, 100K miles and are still going strong.

Our C-7 presently has over 70K on it and, at last check, when I pulled the radiator and CAC, that fan hub bearing was in flawless shape, and that was around 12-15K miles ago. That's not to say it's in perfect shape as we speak, I've not been in there to check it presently.

I know and realize that, there's a tremendous amount of strain and torque on that particular bearing due to its local in the engine drive train and, not only that but, the pretty fair amount of heat it's exposed to.

I was just wondering, if you could expand on your experience with the failure of both the lubed ones and the non-lubed ones. That is, what kind of mileage, on the average, would both see before a potential failure? I'm assuming the lubed one SHOULD last longer but, lubed things fail too.
Scott

[wolfe10]

moisheh wrote:
NEVER replace that bearing with a sealed bearing. Contrary to some posts the C7 has a sealed bearing and a short life. Probably due to all the heat in that area. If that bearing lets go you will have a huge repair bill!

Moisheh

Let me expand a little, since Caterpillar has both sealed and greasable hubs available.

From BEST to WORST:

Greasable bearing that YOU DO GREASE.

Sealed bearing

Greasable bearing that YOU DO NOT GREASE.

[moisheh]

NEVER replace that bearing with a sealed bearing. Contrary to some posts the C7 has a sealed bearing and a short life. Probably due to all the heat in that area. If that bearing lets go you will have a huge repair bill!

Moisheh

[wolfe10]

haddy1 wrote:
When I owned a 3126, I added an extension hose to that fitting and secured it to the breather pipe so I could lube from the bottom.

An extension done properly is OK. But make sure you have purged all the air from the extension before installing it. Said another way, fill the extension with grease before installing.

That is the only way you will know that that small squirt of grease is a small squirt of grease getting to the bearing instead of a couple feet of AIR. The air has no lubrication properties and if trying to purge the air from a long hose could blow the seals.

Since access to to the bearing/zirk depends on coach layout and how much attention the builder paid to "top of engine" access, there is no "one way is better than the other".

[gatorcq]

for those of you who have the CAT, that bearing is 2 inches wide, and is heavy duty. Even if the bearing let go, it does not go though the CAC. Yes you can pay upto 3000, but most of the $$ goes to the service shop labor.
And there are not as many failure as told by people Vs CAT engines on the market. For $60 you can go to any CAT and purchase a new bearing to keep on hand.
However to remove it, the bearing has to be pressed out and back in. A good electric motor rebuild show can do the pressing.
Freightliner Gaffney, usually only like to change the complete housing assembly. But for me,, they removed the housing and I went in search of a place to press out and back in of the bearing. That is where the electric motor shop came in.

And while you are at the CAT shop, need your engine serial number, ask for the image showing the assembly.
And NO, I did not have a failure, I was having the fan replace do to some nicks. I figured, while they were doing that, FL could remove the housing.