My 955K Rattletrap Adventure

[CavinJim]

The Rattletrap...

My new-to-me 955K arrived! (for a little background on how I got to this point, check https://www.heavyequipmentforums.com/showthread.php?64338-Need-some-advice-on-t-loader-dozer )



I've had the worst case of buyer's doubts I've ever had with this machine! I lay awake nights worrying about what I might have missed, how many horrible things might need fixing....and reading horror stories on HEF makes me quiver. But it's mine, now, and my leaks and .... So it came home on a removable neck trailer, which I was very glad to see! The last two trailers I unloaded and loaded were flatbed deck-overs. I didn't find it much fun loading a JD 555 with a backhoe attachment AND a Cat 112 motor grader on the same trailer! I wish I had a photo of that..... Anyhow, it was a cold (cool to some of you) 40 F out (with a meddlesome, biting wind), but the 955 started right up after about 90 seconds of preheat. Off the trailer and down the hard-packed gravel road to the driveway. And that's where I became very glad it had triple grousers instead of a single grouser bar! That cage and ROPS and every access panel and my teeth and brain jelly rattled with more clangs and clanks than anything I've ever driven! Or heard, for that matter! And with the ROPS cage looking an awful lot like a trap--I couldn't help but think of the ol' yeller caterpillar as a rattletrap.

I didn't want to start-stop-start-stop the engine, so I left it idle while paying the man and helping him back out of the road, then it was time to drive the 1/3 mile drive to the shed. Now the previous owner had reported the 955 overheating, so I watched the gauges carefully being already more than half-paranoid and fearful of throwing a rod before getting her settled for the night. Ah, that gauge on the lower right, it's creeping up, higher and higher! Oh, my! What have I done! After a half-hour of idling and running 3/4 throttle the water pressure gauge has creeped into the yellow! Wracking my brain (or what's left of it) about what could be causing a high water pressure, I jump to the conclusion that the head is cracked and all hope is lost. Later that night, a web search reinforces my conclusion. A fretful night follows......

 

[CavinJim]

Oh what a relief....

Next day. Can't get over to make a proper bed for ol' Rattletrap till late in the afternoon, all the while anxious to check for blow-by and bubbles in the radiator. The feeling of doom lingers. Especially after I realize the manuals sent with the machine aren't the proper manuals! They are for a 955, not a 955K, S/N 85J1360! Sigh.

Check the fuel level, pleasantly surprised to find it's at 60%! Check the coolant--normal, no signs of oil. Check everything else, normal (except for the hydro fluid--5 of the 6 cylinders leak, so it's low for the moment). Leave off the radiator cap so I can watch the bubbles blow. Starts up just fine. And what is this? The coolant is circulating and no bubbles to be seen? That can't be right! hmmmm. Time to remove the oil-filler cap and watch the fumes roll out of the crankcase. But no! Not a fume or a fumarole or even a hint at a vapor! Yay!

Time to take Rattletrap out to play in the field. Consolidated an old burn-pile, mostly trunks and stumps. I put the 4-in-1 into "dozer mode" and am pleasantly surprised that I can't feel when it starts peeling away dirt. No difference in pushing sticks or taking off 8" of the old field! That sound you heard earlier was my sigh of relief! So far, the only bad things are leaking cylinders, a leak on the left final drive, and marginally low fuel pressure.

Now for the questions. I expect this adventure is going to require numerous questions on my part.

1: the 955K spent the last couple of decades mostly resting in a shed. The previous owners kept the batteries charged and took her out at least once a year to exercise the hydraulics, but for the most part she sat. Hence the hydro cylinder leaks. It seems to me that the cylinders are leaking a little less now that they've been worked some. Do I go ahead and replace them now or use it for a few more hours to see if any of them will reseal? I doubt they will, but it would certainly save some effort!

2: the p.o. was using 303 universal tractor fluid in the hydraulics, is that right? What I've seen from Cat says 10W and my understanding is that 303 is 30 wt. Do I need to immediately drain and flush the system or is it OK to keep on with the 303? I understand that they changed all fluids this past summer.

3: Do I worry about the water pressure or just ignore it? From what I've read, Cat did away with the water pressure gauge because it really didn't mean much. Everything seems to be flowing fine and the water temp has hardly budged off the low end. My thoughts now are just wait-and-see. I'm not going to be working Rattletrap that hard or long at a time.

4: I've noticed an occasional puff of whitish smoke. It's not much and not too often (maybe once in 30 seconds). As a reference--she's running at an idle in the photos in post 1. There's the expected puff of a little smoke when the load is suddenly increased, but other than that it's all clear. Anything to be concerned about?

5: The final drive leak. This could be the biggest headache. I looked at it very carefully before buying and determined the leak is coming from the oil-pan gasket. My assumption at the time is that it might be leaking from the pinion or axle seals. But, looking at it more carefully the filler plug is above the leak, so it might just be the gasket that's leaking (that would be an easy fix!). I am thinking of just getting the gasket and seeing if that fixes the leak. Any other ideas?

6: The service manual they sent along was for a 955 with older S/N prefixes. However, there's a portion of a section in front that appears to be an addendum for a 955K. Is the 955K manual just an update of the one I have? I'll spend the $100 to get the 955K manual unless someone thinks otherwise....

7: Is there anything I really need to double check before the next 8 hours of use? The previous owners were sticklers for maintenance. They even sent a small filter and gasket (CAT part 5S7645) via UPS and I don't know what they go to yet!

I'll post more photos when I get the chance to take them.

--Cavin

 

[JBGASH]

Cavin, looks like you got a nice one from the pics, as with anything used there will be a few items to fix. Give it a complete service and close looking over and hopefully your fears will be at rest. Good luck.

 

[Delmer]

1. I'd expect to replace the seals but a few hours won't hurt anything to see what they do. What do the wipers look like? the outer part you see is there to wipe the dirt off the rod coming back in, not to seal the oil. If that's damaged, the seals won't last long, even a perfect wiper lets more dirt in when the rod is covered in oil.

2. Run the original fluid until you've figured out what you're doing with the cylinders, and after you've replaced the first round of hoses.

3. I've never seen a water pressure gauge, watch the temp gauge closer than the pressure gauge, make sure it's not losing coolant. Maybe hook a known good gauge up to the pressure port and see what temp it builds??? AFAIK, the pressure is determined by the radiator cap, the ratio of air left in the top of the radiator and the temperature change. Do you have an inch of air in the top of the radiator, or filled to the bottom of the neck? FInd the petcok on the radiator and after you work it a couple hours, drain a quart of coolant into a clean jar to see what it looks like and what settles out to see if you want to flush it. If the temperature gauge climbs anything above the thermostat opening temp in cool weather, then blow the dirt out of the radiator, you might end up removing it, or any oil cooler in the way to get at the radiator to clean it right.

Drain some fuel out of the tank before you use it every time to start. Hopefully you have a handy drain valve? I'd use up all the fuel in that tank and maybe even run a tank of bio blend through it, IF you're going to use up the second tank within a month. Maybe somebody who knows that fuel system will kill the bio idea?

 

[Nige]

Cavin, post a photo of the gauges and describe what function you think each one performs. Seeing a photo of the gauges someone here will be able to tell you what they all mean. There is no such thing as a water pressure gauge AFAIK.

 

[Hobbytime]

nice purchase, now run it to get the cobwebs out of her, then see what is leaking and if there are any bigger problems lurking, then you can make her pretty looking...

 

[CavinJim]

Delmer, I'll take a closer look at the wipers when I'm over there today. I'll be able to take some more photos as well. The p.o. cleaned and flushed the radiator and oil cooler in June and the coolant looks brand new and is right at an inch below the filler neck, as it should be. They also drained the fuel and blew out the lines. Not sure I'll have time to push her hard enough today to budge the temp, but I definitely keep an eye on it!

Nige, I'll provide photos, and I was scratching my head when I saw "water pressure"!

 

[d9gdon]

I've seen those water pressure gauges on track loaders from the 70's era machines. I don't think I've ever seen one that is still functioning and I never knew the reasoning behind them.

http://www.ebay.com/itm/CATERPILLAR...947755?hash=item28239966eb:g:ipgAAOSwB09YGhJc

 

[Dickjr.]

My o2 , if the fluids are full , and its not making any noises that it shouldn't , run it and enjoy it. Sure you might have a few bugs show up but its not a spring chicken anymore. Its a nice looking loader , I like the sweeps / roll over protection. Looks sturdy. The puff of white smoke could be a sticky injector. Run time seems to either help this or bring out what needs attention. On these older diesel engines , I like to add a little 2 stroke oil every so often to help lubricate the system. Some agree , some don't but I think it helps with todays diesel fuel being so dry.

 

[kshansen]

Cavin, post a photo of the gauges and describe what function you think each one performs. Seeing a photo of the gauges someone here will be able to tell you what they all mean. There is no such thing as a water pressure gauge AFAIK.

Well I do recall a couple dozers from years back that had those "water pressure gauges". As I understood it they were to let you know if the cooling system was sealed up and pressure cap functioning correctly. Actually the pressure regulating valve was a separate item from the actual radiator cap on most of the older Cat equipment!

Those gauges were probably designed by some engineer who was trying to convince a boss he was doing something important!

 

[LDK]

Every D8H either 22a or 68a I ever ran had a water pressure guage. Also I am pretty sure that I have run D6C, 7G and 9G's that had that gauge too. I seem to remember being told that if the needle in the water pressure guage was in the same colour range as the needle in the water temperature guage, things were ok even if it was running a bit hot. If this is nonsense, appologies, my memory is not what it was. I only operated them, I didn't fix them!
Didn't the 8K and 9H have the pressure guage too?

 

[Welder Dave]

Loosen the tracks some. They look real tight.

 

[DMiller]

First thing I would do when warms some is pressure wash the ENTIRE machine. Looks to have been pushing in some sloppy stuff at some point, and yes get the rails released a little, some slop is better than too tight. As to getting high on pressure also check the radiator, the belly pans and anything that can trap dirt/mud/debris around the engine or trans/converter, will cause it to hold heat better and longer if not to excess. When wash it, and it will look nasty wash the radiator from the front into the engine compartment, these have 'Pusher' fans where any oil dust dirt or critters get packed into the backside of the radiators, be rather gentle on the core just moving dirt and crap not trying to peel paint.


PS, invest in some good grade earplugs/ear muff/noise cancelling headset, the cage also acts like a drum container where small noises are amplified, no need to add going deaf to old age issues!!

 

[Cmark]

Here's a discussion on the water pressure gauge thing.

https://www.heavyequipmentforums.com/showthread.php?19309-water-pressure-guage

 

[LDK]

Here's a discussion on the water pressure gauge thing.

https://www.heavyequipmentforums.com/showthread.php?19309-water-pressure-guage

Cmark, Thank you for that, feeling a lot better about my memory now
All the best for 2017,
Russ

 

[Delmer]

Here's the relevant directions from Cmark in the other thread:
(Since the links in that thread don't work anymore and this is more clear than Post #11 LDK)

"When the water pressure is in the green, you read from the green scale on the temperature gauge.

When the water pressure is blue, you read from the blue scale on the temperature gauge.

When the water pressure is yellow, you read from the yellow scale on the temperature gauge."

.

Old MF's had a temp gauge with different scales for different pressure caps. A temperature that is overheating with no pressure is fine with 15 PSI's. The temperature of the coolant doesn't cause problems so much as the boiling of the coolant causing steam pockets and localized overheating/cracking. The cast iron doesn't care if the coolant is 200 or 260 as long as it stays liquid. The temp gauges are telling you when the coolant is in danger of boiling, which is more important than the actual temperature.

 

[d9gdon]

I would say that those intermittent puffs of white smoke is from a pinhole in one of your pre-combustion chambers. That is usually caused by the owner not keeping the coolant serviced with anti cavitation additive. The chambers just screw out of the head with a special tool available on Ebay or at your dealer, 5F8353. The chambers have a couple of o-rings on them as well and are torqued down I think to 150 lbs/ft.

 

[kshansen]

I would say that those intermittent puffs of white smoke is from a pinhole in one of your pre-combustion chambers. That is usually caused by the owner not keeping the coolant serviced with anti cavitation additive. The chambers just screw out of the head with a special tool available on Ebay or at your dealer, 5F8353. The chambers have a couple of o-rings on them as well and are torqued down I think to 150 lbs/ft.

There is a "special" procedure for installing the chambers to be sure the glow plugs don't interfere with the manifold. If you are going to do this let us know and myself or someone else can forward the info to you. I requires using an assortment of different shim washers, nothing complicated but needs to be done.

 

[Tinkerer]

A lot of that rattling noise may be caused by worn out rubber bushings where the ROPS is it is attached to the tractor. They can be deafening even with hearing protection.

 

[CavinJim]

A lot of that rattling noise may be caused by worn out rubber bushings where the ROPS is it is attached to the tractor. They can be deafening even with hearing protection.

Bingo! Someone had actually welded the ROPS down to try and quiet it. The welds are all broken, thankfully!

I finally got over to clear out a bay in the machine shed for the 955. Will post some photos and more info later tonight. I'll just say that machine is fun to run! If it works this well as old as it is, I wonder what it was like new? I didn't notice much in the way of the smoke puffs today.