My 955K Rattletrap Adventure

It took me a while to figure out where all of that loud rattling sound was coming from. When I really get fed up with the noise I am going to drill and put a tight clearance bolt through all four post. just after I got my loader I found one of those rubber bushings on the ground. I had no idea where it came from or what it was.

Nige said:

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.

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The Gauges

Good thing I'm a night-owl. Or an insomniac, one of the two.

Nige: first of all, I was thrilled to see you had posted to this thread! I read your posts with great interest as your knowledge of heavy equipment is encyclopedic. You had me questioning what I had seen and I didn't want to address the gauges until I could double check things and take some photos. So, here they are:



Clockwise, from upper right, the gauges are ammeter, fuel pressure, engine oil pressure, water temperature, water pressure, and converter temp (F). The two knobs: left is the preheat/start and right is the lights (most of which work, amazingly!).

The left cluster in more detail:



The upper left gauge is the torque converter temperature. Why it is labeled as "TEMP F" is beyond me as it is a qualitative gauge (it has no numbers), so why specify Fahrenheit? It could be in Kelvins or yo-yo degrees.... Anyhow, this gauge doesn't seem to work as it hasn't moved a bit. But it could also be that I haven't worked it enough to make it move!

Below the converter temp is the more interesting water pressure gauge. The colors are faded, but the bottom segment is green, the middle is blue, and the top right is yellow. To the right of that gauge is the water temperature gauge. Again, it is faded--the bottom portion is green/red, the middle blue/red, and the top yellow/red. The quotes by Delmer (post #16 herein) are right on. Specifically, the row in the water temperature gauge corresponds to what color the water pressure gauge is pointing to. The higher the pressure, the higher the temp can be without boiling. Personally, I think that is a great combination to have! It tells you a lot about what is going on in the cooling system. Today (er, yesterday), I ran the rattletrap for about a half-hour (all I had time for) a good portion of which was at or near full-throttle. I did some pushing, dropped a couple of trees, and otherwise just played around getting used to the machine. The water pressure gauge never moved out of the green zone and the water temperature gauge barely budged. After I parked it (running it at an idle for about 5 minutes in the process) and with it running I opened the engine hatch to see if it felt hot to double check if the temp gauge was accurate. It didn't seem to be hot at all. I checked the radiator hatch. The radiator was cool enough that I could lay my hand on the tank! If anything, it is running too cold. I'm wondering if the previous owner removed the thermostats (can't find that info in the manuals I have--might have to dig some more). Anyhow, until an issue presents itself, I'm not concerned about the cooling system.

Regarding the other gauges: the engine oil pressure jumps immediately into the green and stays there. The ammeter gauge works as it should and the batteries are doing their job (thankfully!). But the fuel pressure gauge is in the yellow unless it is at full-throttle at which point it is at the very bottom of the green. As there doesn't seem to be a loss of power (at least not that I can tell!), I'm not going to sweat that, either.

d9gdon said:

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.

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I was wondering if there was a way of getting an occasional drip of coolant into the combustion chamber--this might be the solution. Is there a way of testing that? And is the anti-cavitation additive available separately or do I need to drain and refill the coolant entirely? I will check with the p.o. what he was using. But, on the other hand, I will wait awhile and see if the puffs were my overactive imagination. I made note of them while driving over our nearly half-mile long driveway which can be quite boring. I was paying far more attention to details that would otherwise go unnoticed. Today I was actually using the machine, paying more attention to my surroundings and where the bucket was relative to the ground than I was to anything coming out of the stack. I found that I could hold the powershift lever and throttle at the same time and that seemed really handy! Except for when I tried to shift the throttle into reverse... that doesn't seem to work too well. On another note, all of my other machines (two tractors and a JD 350 crawler-loader) have joystick-style loader controls (up-down is the boom, left-right is the bucket). No matter how hard I try, I can't get the boom lever on the 955 to go left-right to dump the bucket!

Nitelite said:

It took me a while to figure out where all of that loud rattling sound was coming from. When I really get fed up with the noise I am going to drill and put a tight clearance bolt through all four post. just after I got my loader I found one of those rubber bushings on the ground. I had no idea where it came from or what it was.

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Nitelite: I read your thread a couple of weeks ago with great interest and have been keeping up with your truck/trailer adventure. I am quite happy to have you post here. Thank you! As DMiller suggested--I have really good hearing protection so I don't much notice the rattle, clank, bank, clunk, cling, bonk, unless I'm on a harder surface. I like my hearing so I've always used ear plugs or muffs (or both) when using any engine-powered equipment including the lawn mower, string trimmer, chainsaw, and all the tractors and the like. The 955 is not the loudest or most aggravating machine I own! I think the loudest goes to the two-cylinder Yanmar.... though the three-banger JD 5075 tractor is right up there! And I am planning to have those rubber bushings on hand if I ever need to pull the ROPS. I don't think it's worth a special effort.... though I may change my mind. My rattles also come from the hatches--like the battery access hatch that doesn't quite close right. I think there's some others that add to the din, too.

Good luck on fetching that trailer!

Ah, I just thought of a few other things mentioned above:

Pressure washing: yes, she needs a bath and will get one just as soon as the weather cooperates (i.e. it won't be below freezing for a couple of weeks).

Rail tension: yes, the rails are a bit too tight, but they aren't as tight as what looks like in the photos. There's a good inch of droop between the idler and the carrier--but that's still too tight. I'll address that next time I wake her up. She's taking a nap for the next couple of weeks.

Aggravations: this is a general gripe, not particular to this machine. With a 4-in-1 bucket (or even a g.p. bucket on many t-loaders), you can't see the bottom of the bucket when it is on the ground. On my 955, you can't even see the lower half of the bucket! It's going to take a bit longer than usual to get the feel for where it's digging or riding on the surface. Any suggestions on that front? The hydraulic response is great--I can easily tweak the bucket position by less than an inch. But precision without accuracy is rather meaningless! Guess it's down to practice.....

I am beginning to wonder if the water pressure gauge is for running straight water which boils quicker than coolant. Complete speculation on my part. As far as digging technique , the older front engine loaders , Keep the back of the bucket flat and tilt forward until the engine loads a bit. The engine load tells how deep the cut. To shave a few inches , take the teeth and rake it forward then set the bucket flat and clean the loose material out. Track loaders are the harder machine to learn to run but when learned they are the most efficient.

For final trimming roll the bucket back or forward rather than using the main lift arms, it works a treat.

Cavin: If you replace those bushings now you will be amazed at the difference in the noise level you will be hearing .
FWIW (probably nothing)! I remember seeing water pressure gauges on Caterpillar machines when I ran a service truck, but I don't recall what particular machines they were on. I found this info on a quick Google search.

Parts scheme 9S2326 WATER PRESSURE GAUGE GROUP - 9s2326 - Caterpillar part
Models comprising the spare part 9S2326 WATER PRESSURE GAUGE GROUP
ENGINE - MACHINE
3306;
PIPELAYER
561B; 561C; 571G; 572G; 583K; 594; 594H;
TRACK-TYPE LOADER
955; 977A;

Nitelite said:

It took me a while to figure out where all of that loud rattling sound was coming from. When I really get fed up with the noise I am going to drill and put a tight clearance bolt through all four post. just after I got my loader I found one of those rubber bushings on the ground. I had no idea where it came from or what it was.

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We had to replace the rubber bushings at the base of the ROPS on my 955L & it was much quieter after. They were quiet expensive though......checked for Cat Classic & were told they were not available. I think it may be better to replace the bushings rather than put a "tight bolt" in........ easier on things & absorbs the vibration better.

If you want to try to get that transmission temp gauge working, take out the sensing bulb and put it in some smoking hot oil, then tap that gauge until it move to hot. If it does, remove the sensor from the oil and let it cool, tap and repeat. If it doesn't move when hot and tapping, then the freon is gone from the sensor and it won't work, like the guy found out after he broke the glass trying. I'm assuming the temp gauges use capillary tubes, if they have a wire then never mind.

Cav - nice photos. Kudos for that.

I must have just missed the water pressure gauges. The oldest 955 I ever recall working with was an L series around the 1977 time frame, but hey ho.
The only thing I can suggest is to get into the back of the dash panel and try pressurizing the gauge manually, maybe by using an adapted bicycle tire pump or similar. That will tell you if the guage is working or not. If it is then you'll be off on a detective mission to trace the pipework all the way to the cooling system to see if you can find a leak in it (or has it even been disconnected at some point between the guage and the cooling system..?)

The converter temp gauge looks like it's goofed. Could be the capillary bust, could be the gauge. Again it'll be a detective mission to find out where the failure lies. Removing the bulb from the converter housing and subjecting it to some heat like dumping it in boiling water would be a good test. That ought to generate some reaction from the needle.

Delmer and Nige, Thanks for the advice regarding the converter temp gauge. I'm going to have to give that a try. One other question regarding the dash area--in my photos of the whole dash you can see a gap of about one inch in the housing above and behind the dash area--is this a purposeful gap? That is, is it supposed to be there or is there a strip of sheet metal missing? I haven't been able to find that detail in any of the books I have, but as they are for a 955 and not a 955K, they might differ on that detail. It just seems out-of-place....

Some photos of the rails:
Right side:


Left side:


It's hard to see in the photos, but if you feel the bushings it is very difficult to feel any wear--it seems like they are almost perfect cylinders still. That, along with them being SALT (they have the rubber plugs in the ends of the bushings), is what sold me on the machine. I looked at the sellers (brother's whose dad bought the 955K in the mid-90s, built a pond, then parked it) and said "you guys didn't put many hours on this, did you? Not much more than a few hundred?" They looked at each other and said, "That's about right." Someone put a lot of money into the undercarriage just before their dad bought it! Other than loosening the track tension a bit, I doubt I'll have to fret about the undercarriage!

A belated very happy and merry New Year to all! I even had some hog jowl and black-eyed peas with the in-laws on 1 Jan to ensure a lucky year. Unfortunately, my vacation is over, now, and it's back to the work-a-day world tomorrow.

--Cavin

Am I missing something? As in, do I need my head examined?

It seems to me like adding hydraulic fluid should be a no-brainer. The fluid was a little low (had just disappeared from the sight glass), so I decided to add a bit. Still need to fix the cylinder leaks, so it's not unexpected to have to top off the fluid now and then. Still haven't put more than an hour on the machine. So.... I go to add fluid a few weeks ago and being a bit overzealous (and it being on the chilly side), I poured a bit too quickly and the strainer inside the tank didn't keep up and it backed up and overflowed. Sigh. I clean up the mess as best I can, look in the sight glass and no fluid there. I let it set for awhile and it went down a bit, so I decided to start it and let it run for just a few seconds to get the fluid to circulate. Did that--and the level went down and I called it a day.

Last week, when it was nice and warm, I went back to run the machine a bit and decided to top off the fluid as I never did that successfully. I went to open the hydraulic tank cap and it started gurgling and spitting. Pulled the cap off and at least a quart of fluid gushed out of the tank and made another royal mess! Sigh. But--I can't for the life of me understand how there was fluid in a position to blow out the cap but not show in the sight glass!?! Am I missing something? I've poured over the parts illustrations, and it looks to me that the fluid should dump right into the tank from the filler cap (after it seeps through the strainer). The pressure is understandable--it was at least 20 F warmer than last time I had the cap off. It's probably nothing, but I really don't like not understanding something.

I finally got the right parts and service manuals. The parts manual looks nearly unused! There's a sticker on the cover, top right, that says "Master Copy". Definitely no greasy finger prints anywhere on it! Certainly not like the (incorrect) parts book that came with the rattletrap--more grease than ink, falling apart, and notes scribbled all over. In other words, perfectly normal. The one I just bought has to be an aberration!

If anyone has any ideas how the tank can overflow after sitting for a few weeks and nothing showing in the sight glass-please enlighten me! (If I didn't know better, I'd say the sight glass ports are plugged--but I know it works as it should.)

I have had similar things happen with the oil being somewhat low & then when trying to add oil it gurgles up & the boiling out problem when you take the cap off too. Seems they are designed to have a few lbs. of pressure inside when operating & I always wondered if that may be the cause if some of those antics?

The tank cap is designed to seal tight so that when the hydraulic oil is at operating temperature the pressure created inside the tank aids the flow of oil into the suction side of the implement pump.
The cap is only supposed to be opened when the oil in the tank is at ambient temperature, if you try it with oil hotter than that the result will be what happened to you yesterday.

Nige said:

The tank cap is designed to seal tight so that when the hydraulic oil is at operating temperature the pressure created inside the tank aids the flow of oil into the suction side of the implement pump.
The cap is only supposed to be opened when the oil in the tank is at ambient temperature, if you try it with oil hotter than that the result will be what happened to you yesterday.

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What kind of pressure are the older Cat's designed to carry in the hyd tanks? Is there a relief valve to keep them from "over pressurizing"?

I'm familiar with the tank pressurization as my Deere crawlers work basically the same way. It was at ambient when I opened it, but ambient was about 20 F warmer than the last time it was opened. As usual, I loosened the cap and let the air spit out to relieve any pressure, thought it was finished but that's when a good quart (or more) of fluid burped out in one big glug. I'm just wondering how that much fluid would be in a position to burp out when the tank level is quite a bit below the cap.

Oh, I think I know the answer. The strainer is in a tube and the bottom of the tube must be in the fluid. That begs another question: in a similar situation, how can you open the cap without the same thing happening? We've been on a temperature rollercoaster lately. Today is supposed to be 25 degrees F warmer than yesterday.

Metalman 55 said:

What kind of pressure are the older Cat's designed to carry in the hyd tanks? Is there a relief valve to keep them from "over pressurizing"?

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Probably a couple of psi, no more. As to whether there is a relief valve on a particular model, take a look on top of the hydraulic tank and compare it to the Parts Manual. So have, some don't.

I was afraid this might happen....

I'm finally getting to spend a bit more time here and there with the 955 and have found a bit of a problem.... I knew there was something amiss as the batteries just wouldn't hold a charge and never seemed to recharge. After trying to charge them off of 400 ft of extension cord, I found the problem--one of the batteries was toast. New batteries (and a lighter wallet) later, the rattletrap started with gusto--what a difference better batteries make! But a voltage check confirmed my fears--it wasn't charging.

When I took a closer look at the voltage regulator I did a double-take: the "bat" lead was connected to the "gen" terminal, along with the "gen" lead! I know you jump them together to polarize the generator, when necessary, but to leave them connected?!? Hopefully it didn't fry the generator.... but I think the regulator is toast.

The voltage and current regulator is a Delco-Remy 1119653. The D-R service bulletin is 1R-119A--but I cannot find it anywhere. It also turns out this belongs to a unique series of regulators all under that bulletin--they have a double contact voltage regulator with upper and lower contacts. Worse yet, the upper contact was welded together and appears to have almost completely melted and the field resistor is bad (obviously broken wire). Still need to check the generator output, but I'm hoping it's just the regulator.

So... if weather cooperates I'll check the gen output and call the Cat house Monday to see about the availability of a replacement regulator. From what I can see on SIS, there might be a replacement regulator for about $100. But I'm open to some suggestions! I'm presuming it would be best just to upgrade to an alternator if possible, but I presume that will require a bit of rewire.

I did finally get the air pocket out of the hydraulic tank. I waited for a good cold day and opened the lid so it sucked in air instead of blowing it out. Was able to top it off with a couple of gallons.

My old machine is generator equipped, I searched far and wide to find a 24v regulator for a no switch ignition system, then found the generator itself bad and no one in the area willing to rebuild it. Had plans to send it off then found could buy a single wire alternator to replace my generator. Required a mount conversion but simplifies the wiring, eliminates the external regulator only difference I have to change the machine from + to - ground. Got it on Sleaze-bay for less than I could get the generator rebuilt.