CAT 955K TURNS over but wont run.

[Themaskman72]

I recently acquired my first (2) pieces of heavy. One is a CAT 955K 1970. Previous owner said it ran great when he parked it. After it Sat for a year he went to move it and it would turn over but not start. So it Sat another year and Now I have it. He also said that it has 80 hrs on a New block replacement because his buddy ran it hot and cracked the other. What I have done so far......brought the (2) massive CAT batteries back to life and they are holding steady at 11-12 volts. Put fresh diesel in. Primed it. Put (2) gallons of antifreeze in. Still won't run. Fuel filter is full of diesel. I cracked open each fuel line at the injector and pumped the primer and fuel sprays out of each. It turns over and over and nothing, no smoke or anything. Also I used a half a can of ether with no affect. I also added 3 qrts of oil and the oil is not milky. I should also mention that the exhaust pipe was wide open and I don't know for how long. Oh and I also took the intake pipe off to confirm the turbo wheel is freely spinning and it is. Gauges don't appear to work at all. Please if you can give me some ideas on what to try next or what am I missing to get this machine going, thanks.

 

[Delmer]

Only thing I see wrong is the batteries should be 12.5v minimum. 11 or 12 is way too low. On the other hand if it turns over good, then maybe your voltmeter is the problem, not the batteries.

" I cracked open each fuel line at the injector and pumped the primer and fuel sprays out of each. " so the injector lines spray fuel from just pumping the primer? or when cranking over? Just curious, I don't know what that would mean in this case, just seemed odd.

Any glow plugs on that thing?

 

[Shimmy1]

I don't know about this particular machine, but a lot if machines of that vintage you need to open the throttle up to turn the fuel on. Old front-end loaders you just press the accelerator pedal down. I'm thinking tctractors has said before that the fuel pump will leak fuel through and out the injector lines with the throttle closed? You need to be getting fuel up to the injectors while cranking.

 

[Welder Dave]

Leave the ether alone. You should be getting smoke out the exhaust if it's getting fuel. My 931B I usually start a little under 1/2 throttle. Once warm it will idle slower but cold needs more throttle till it keep running at low idle.

 

[Themaskman72]

I'm not getting any smoke when it turns over. What can cause the fuel to make it to the injectors but not to the cylinders? Also glow plugs are no good, wires are broke off them.

 

[Themaskman72]

Also throttle has to be on for it to start according to what's stamped where the throttle is.

 

[Shimmy1]

Are you getting fuel at the injectors while cranking?

 

[Themaskman72]

Didn't check that, I will tomorrow. Let's say I am not, what would be the issue?

 

[thepumpguysc]

Loosen the lines AT the injectors.. all of them..
Hold the throttle wide open.. crank the engine..
Fuel should squirt out the end of the lines w/ some pressure..
IF they don't and it just dribbles.. it could be the control rack in the injection pump is stuck in the shut-off position..
Get the GLOW PLUGS FIXED 1st..

 

[kshansen]

Agree with those that say don't even think of ether! If you are not seeing white smoke while cranking you are not getting fuel to the cylinders.

Never seen a 955, do they have a foot throttle like a front end loader or a hand throttle like a dozer?

Okay, checked SIS it is hand control for governor, when moved from stop to run position does it snap in and out of the detent? Might have to move all the way to full fuel position to get it to go "snap". If it is not snapping in and out could be a linkage problem. Try working it at the injection pump itself, may need to disconnect the linkage to be sure. If it is snapping in and out but still no white smoke while cranking thepumpguysc is probably right about the control rack in the pump. Maybe he could give you some ideas on freeing it up, might need a picture of the pump so he is sure which style you have.

Even if you do start to see the white smoke while cranking, which would mean you finally have fuel being injected, you really need to get those glow plugs working. Even when new at any thing under 60ºF that engine needed them to start good. Here's the chart that should be on the machine some place:


Just did a quick check on SIS about that wiring harness that connects to the glow plugs, part number 7N9634, it shows as being available and only $49.00 so no reason to mess around trying to stat without it working. Of course you will need to test the glow plugs. Don't have the spec's for the glow plugs in a 3304 or what engine you may have but the specks for a glow plug in another larger Cat engine show as 4.5 ohms each and they draw approx. 6.5 amps each at 24 volts that should be close enough to let you know if they should be working

 

[Old Magnet]

A 955K 1970 model would be a 85J2528 to 85J3483 s/n with D330cT engine. 3304 didn't come in until s/n 85J6247
Glow plug harness is a 5S8480
Glow plugs are 1P7324

 

[Themaskman72]

Thanks for the help. I'm headed out to work on it now. I will update you guys on what happened when I try what you told me. I will also get some pics. Thank you very much.

 

[kshansen]

A 955K 1970 model would be a 85J2528 to 85J3483 s/n with D330cT engine. 3304 didn't come in until s/n 85J6247
Glow plug harness is a 5S8480
Glow plugs are 1P7324

Guess I should have asked for a s/n before saying too much, I had just took a wild guess and picked the middle of the list on SIS, 71J , sorry!:crazy:badidea


And that correct part number for the wires is actually a bit less money About $39.00! And it is actually in stock at my local Cat house!

 

[auen1]

My secret trick is to pour a little gas on a rag.
And hold it up to the air intake.
Make sure the rag doesn't get sucked into the engine.

Works 4x better than ether and doesn't knock.
Gets that diesel moving toward the pistons.
Use at your own risk, but it works for me.

Got me out of a jam, when I was stuck in the middle of no where.
Bad injector pump, but got the truck running and back 300 miles to the nearest parts store.

I'm sure some here might say not to do this.

 

[Themaskman72]

Ok guys just found the serial number finally. After aggressively cleaning the plate the number is 85c7815.....correct me if I'm wrong but doesn't that mean that this machine is actually a 955L with a 3304 engine? If so use the information I gave you earlier and see if it makes a difference in trouble shooting. Btw I cracked the fuel lines at the injectors and turned the engine over, all lines push fuel out, the second back appears to be pushing a lot of air bubbles out also, the others straight fuel, thanks.

 

[Themaskman72]

Correction, the serial starts 85J, not 85C.

 

[thepumpguysc]

If you added fresh fuel to the old fuel, your wasting your time.. gotta drain it, drain the filters and start again..
Pull the glow plugs, put 12-24volts to them +on top, - on body.. count to 10-15 and if they aren't glowing red/white hot, throw them away.
Once the gp's are sorted out, reinstall.. take a volt meter and see if your getting voltage TO THEM..with the gp's activated, either w/ the key or push button..
If not, you can either waste a lot of time figuring it out or just run a hot wire to the first or last one, closest one.. it will feed the rest.. hold the wire on for a 30 sec count and try to start the engine.. watch the exhaust and report back.
DONT USE either or gasoline while using the gp's.. bad things will happen..

 

[Old Magnet]

Yes, 85J6247 would be a 1972 model 955L with 3304 engine. Still would have the compact fuel injection pump.
Still uses the 5S8480 glow plug wiring harness and 1P7324=3T9562 glow plugs.

 

[kshansen]

Ok guys just found the serial number finally. After aggressively cleaning the plate the number is 85c7815.....correct me if I'm wrong but doesn't that mean that this machine is actually a 955L with a 3304 engine? If so use the information I gave you earlier and see if it makes a difference in trouble shooting. Btw I cracked the fuel lines at the injectors and turned the engine over, all lines push fuel out, the second back appears to be pushing a lot of air bubbles out also, the others straight fuel, thanks.

Well just took a look at SIS and it says a 85C prefix is for a 6A&6S bulldozer, note in Cat speek a bulldozer does not refer to the tractor part just the blade and operating equipment.

Guess I replied too soon oh well, no extra charge for that!

 

[kshansen]

If not, you can either waste a lot of time figuring it out or just run a hot wire to the first or last one, closest one.. it will feed the rest.. hold the wire on for a 30 sec count and try to start the engine.. watch the exhaust and report back.
DONT USE either or gasoline while using the gp's.. bad things will happen..

This assumes the harness connecting them together is in good condition, but on many of the older ones I've seen the wire ends are broken off the wires or the ends them self are worn out and will not hold on to the glow plugs. Like I mentioned if that is the case this new harness assembly is relatively cheap at around $40.00