i have a 980h JMS03132. it has 12,000 hours on it. i bought it used 2 months ago. i have the half wheel command steering. now in the colder weather when i start her up every morning I can't steer or move the hydraulics. it takes like 20 minutes of idling till i can steer. and then another 10-20 minutes of run time till the steering and hydraulics are smooth. i have plenty of oil in the hydraulic tank. i have no codes on Cat ET. It sounds like it sucking air almost but i can't find any leaks. the hydraulic tank doesn't build up much pressure while running. i have rigged up a test port and a gauge in line with the breaker valve on the tank. i was told that these tanks are supposed to be pressurized. when i rig up a fitting and put 10-20psi in the tank on start up the hydraulic start to response much quicker then normal(2-3mins). i believe my problem is somewhere in the pilot control system. Any help would much appreciated. thank you.
Kudos for posting a Serial Number - most people don't. What viscosity of oil do you have in the hydraulic system.? From the symptoms you describe it sounds as though it's too heavy. The clue is that once the machine has warmed up it sounds as though it works fine. The breaker relief valve is a 220-0814 (CRB 507-0644) which is specified as 10psi give or take. Thing is when the oil is cold the tank will have little or no pressure in it so the amount of assistance to oil flow into the implement pump suction will be minimal. If it was fine when the weather was warm and now it isn't my bet is on the oil viscosity.
Pilot pump is air locked sounds like. Confirm by cracking the outlet line on the pump for a few seconds then tightening. It’s the pump closet to the hitch (small aluminum pilot/brake pump). Either the suction tubes or joiner hose or clamps are loose and sucking air. If that’s all good the pump is worn and needs replacement. And yes confirm it’s 10W hyd oil in the tank as mentioned above.
I would also be leaning towards a suction leak or too heavy of oil. A lot of time if a pump is sucking air it will sound like it's trying to pump marbles when cold. Might pay to put say 10 psi on the hydraulic tank and let it set for a while to see if anything starts dripping oil. Might take sometime with cold oil especially if it is heavier than 10Wt
Very common on g's and h's there's big tube for suction line it's kinda hard to get with cab on if it's tighter than a crows foot two foot extension and breaker bar. I usually pull cab change all hoses redo suction line new pilot pump and replace or just remove falling down under cab insulation. Or just show operator the hose on right side above tank to loosen until it pulls prime.
Just a bit of clarification. Just because I said above that the specification of the breaker valve on the implement system is rated at 10psi doesn't mean you will get 10psi of pressure in the tank. Even hot the pressure may be way lower than that, and TBH it only needs a couple of psi to help the oil into the suction side of the pump provided the seals, joints, etc, in the suction lines are good and that the oil is the correct viscosity. The breaker valves are a service item BTW, should be replaced every 2-4000 hours depending on application. Your is probably original for the machine and long past due for replacement What happens if you run the machine all day then when you shut it down you (carefully) release the pressure in the hydraulic tank. Does it release any pressure at all..?
Yes, one of the G's at the quarry had a problem picking up it's prime when you did a hyd. oil change. Found that there was a quick connect for one of the pressure test ports under the right side platform that if you connected a hose to it with the other end open and let machine idle for a few seconds to vent a little air it would be good to go. Another G more or less stumbled on to a factory mistake several years after we got it. I was removing the steering and brake pump to fix a leaking mounting seal. Removed the cab for access and when I pulled the suction line off the bottom of the pump found that when installed at the factory someone had used the wrong seal. The suction line was machined for a standard o'ring but it had been installed using one of those "D" rings and the ring was smashed out all around the groove. Hard to believe they got lucky and it never caused a problem!
That's it amazing oring face orings. Are very small 1/16 ? Maybe d ring maybe 5/16 ? I'd be surprised if a flange seal oring like a 4j-0520 wouldn't push out. a d ring blows my mind
Ks I had a 980h with a broken cab ground cause me to loose slot of hair in two days... It was intermittent. I know you have quite a bit of loader experience is that a common issue?
Well you made me do some checking and it was actually the suction line for the transmission pump on a 980GII machine. The correct seal should have been a 4J0527, so what ever "D" ring is close to that is what I found in there! This machine was new in the fall of 2002 and when I found and corrected the leak it was December of 2013!
Been retired for just short of 5 years but can not recall having that problem. But with the rubber mounted cabs if mounts were getting a little loose and the ground strap/wire was not installed so there was enough slack I could see that happening. As I recall when I did remove the cab from that 980GII the rubber mounting parts were a bit worn. A bit off topic but while reading my notes on that winter repair I saw that the "boots" around the control levers were bad and letting crap get in to the linkage for the hoist control valve. When I checked with Cat they were asking the outrageous price of $75.00 each for the little vinyl boots with a little piece of shoe lace to tighten them on the levers! Being the cheap SOB I am I mentioned it to the working group leader and he said give me one! He took it home to his wife who repairs seats on snowmobiles and she made a couple for free out of some scrap! Just for fun I looked on SIS just now and see they are now asking $79.05 each for those little bits of material! The crazy thing is the levers that the boot goes around are only $34.00!
can anyone explain a bit more where the pilot pump is and what lines to try bleeding. I have never worked on a Cat this big so I'm not too familiar with the machine yet. I'm goin to try an experiment in a day or two and heat up the tank with one of those blower diesel heater to rule out to heavy of oil. once i identify the pilot pump i will check all the suction tubing goin to it from the tank. I hardly get any pressure at the breaker at anytime, hot or cold, on or off.
You said it had 12k hours on it when it was bought. Have you ever changed the hydraulic oil & filters since you had the machine.? An oil & filter change would give you the chance to open up all the pump suction lines and replace the O-Rings in them while the tank is empty. Sound like you don’t have an Operation & Maintenance Manual. That probably ought to be on your shopping list. It’s less than $50 and you can download it from the internet. If you’re not getting any pressure from the tank at any time, replace the breaker valve as a first step. I gave you the number up above somewhere. One thing you never mentioned. Does it leak hydraulic oil from anywhere.?
i can't find any hydraulic leaks on the machine. i changed the hydraulic filter about 15 hours ago. it gave me a hard time getting the hydraulics to respond after swapping out that filter
First question is do you know what oil is in the hydraulics? The number in the above picture point to the suction lines for the following pump: #1 is for the steering pump. #2 Is the transmission pump. #3 Is for the small gear pump that supplies oil to the brakes and the pilot system controls.
If things went South after changing the filter, what brand was it.? TBH I’d still like to know what oil is in it.
I replaced it with a cat filter. I also have a baldwin on the shelf i can try. i topped it off with 5 gals komatsu AW46 that i had laying around. i know i used really use 10w hydraulic oil but i didn't have any on hand.
Also if this is any help the brake warning light. always turns on when i start the machine for like a minute. I'm guessing its a low pressure code and I'm also guessing it has something to do with my issues after reading that the pilot pump runs the brakes
Stick with the Cat filter for now. I was more concerned that you had used a parts store brand X or similar. No it's not. It's the time it takes the brake accumulator to charge up when you start from cold (it will leak down while the machine is parked overnight). If the light goes off within a minute of so of a cold start it sounds like your brake pump is in reasonable shape. And guess what, that's the same pump that runs the pilot system. Now if you had a manual all this, and much more besides, is explained in it. Do you see a recurring theme here..? (see post #13 above)
One thing I'm not understanding is this comment from the first post: It sounds like it sucking air almost but i can't find any leaks. By saying "sounds" do you mean to say it is making some kind of noise?
Ya the pump and the lines in top of the tank sound like they are making a ton of noise until its all warmed up and working properly
Back to the filter. It's on the return to tank line so it can't be sucking air. If it was leaking you would have oil spilling out rather than sucking air in. Interesting that losing pump prime after a hydraulic oil change is apparently not uncommon because the manual mentions a priming procedure using 10psi of air (recurring theme - that darn manual again). See attachment. Take a look at the illustrations below. Three locations I would be looking at. The two flanges (tank & pump suction) each use a 9M-2092 O-Ring. The piece of hose in between the two steel lines uses 9X-2201 hose clamps, one at each end. If it was me I'd try doubling up those clamps as a starting point, or even use constant-torque clamps (P/N 216-6947) in that location which would be a much better idea.
And also check the tubing in those picture Nige posed above to be sure something is not rubbing a hole in one of them. I had a 988 87A that had a hydraulic pressure hose fail. Replaced the failed hydraulic hose and now machine would not move ***? I never touched anything related to the transmission! Well after some good looking I found that the hose that had failed had also been rubbing on the suction tube for the transmission pump! Was one of those got to have it running now projects so removed the transmission suction pipe and brazed on a blow-out patch and reinstalled, good to go! If those lines are making all kinds of noises I would suspect a suction leak or restriction of some kind or too thick of oil. Assuming the cold starting temps are not down near 0ºF and even at that temp proper 10wt oil should be flowing good in a few seconds.
I replace every clamp on a rubber hose goin to those three pumps yesterday. Made little to no difference. Still waiting for my new oil to arrive to change the hydro oil. Do I actually need this oil drain tool? Or can i just rig something up to get the oil out of the tank
Temps are only around 30 dergees in the morning.
No you don't. It's only a pipe nipple of the correct thread that you screw into the drain valve in the bottom of the tank to raise the guts of the valve and allow the oil to drain. IIRC it is a 1" pipe thread. Below is a diagram of what the valve looks like. You remove the green plug #4 and screw the pipe into the same thread that the plug came out of. The drain valve #3 has a pretty strong spring on it so you need a fair amount of force to open it, hence the use of the pipe nipple.
So if there is an air leak in the suction side it appears that it was not from the hose clamps. Are you planning on replacing all the O-Rings in the suction lines for the three pumps when you drain the oil.? If you need more Part Numbers please ask. Don't forget KSH's suggestion of a leak in one of the steel tubes caused by something rubbing on it. The diagrams of the suction lines in post #22 above bears no relation to how many hydraulic hoses there actually are in that area. Something could have easily rubbed through a steel tube. Also are you planning on replacing the tank breaker valve.? I think you should if there is any chance that it's original with 12k hours on it.
metal tube are all in perfect shape. not rubs or rust spots. I'm still waiting on my oil shipment, for some reason the shipment has been very delayed with the holiday last week. I'm going replace the orings in the suction side of the tank, when i drain the oil though. i bought i pressure gauge set up with that quick connect cat fitting this last week on amazon. does any one have a pressure testing procedure and what the values should be for these three pumps for future reference?
follow the small line from pilot pump till it's easy to loosen fitting start and tighten after oil comes out
I hope you're also planning to replace the all of the o-rings on the pump end as well as the tank end. See attached.
thank you for those pdfs. that picture with the cab off is very helpful also. i plan on replacing the rest of the rings if i need to. yesterday morning was a disaster. the machine would turn, no hydrualics, and parking brake would release at all even after an hour of warming up and charging the tank... so i did the oil change with fresh oil that was very cold from also being outside, the o-rings, and the new rubber tubes and clamps. charged the tank with air and she was back up and running great. then it got interesting, i noticed the machine was running hot for a 25 degree day. i hopped out to check everything and the radiator fan wasn't turning. so i parked the machine and let it sit over night. goin to test it right now and see if maybe the fan got air bound or something from the oil change.
28 degrees this morning. Started her up and within 10 seconds the brake pressure light went off. And i had full hydraulic control of the bucket and the steering with a minute. It was erratic for the first minute. Which i think is kinda normal considering how cold it is. The radiator fan is spinning as normal now. Hopefully tht was just a random thing. it looks like im fixed now or atleast bought myself some time before i have replace that pilot pump. Thank you for all of your help and patience. If some one can send me over a cab removal pdf real quick that would be appreciated too for future reference.
Good to hear, at below freezing outside it's likely to take a bit of time for things to start circulating. You have to live with that. Did you replace the breaker valve on the tank..? IMO you really ought to, especially based on the fact that you mentioned there was no pressure generated in the tank under any circumstances, even with hot oil. I'll email you something on the cab R&I.
As for the remove and Install of the cab I'm thinking the "H" is about the same as the "G Series 2". I only had the chance to do it once on our 980G II and the worst part was getting the quick connect for the AC lines to release! Sure makes getting at those lines and the pumps. I was lucky as we had a 40 ton overhead crane in the shop not that it takes that much but never hurts to have the power. Well as long as you do not forget to unbolt the steering linkage, NO! I didn't but that crane would not have noticed! Once cab is off I would inspect every hose under there and replace any that look even slightly questionable! Also figure on replacing a few rubber pads or bushings while cab is off and check the ground straps too! Just for the fun of it here is the seal ring I removed the cab to replace: That's what a "D"ring looks like when some one used one where a "O"ring should be. For the longest time I blamed that mistake on the factory but while skimming through the records on the machine I see that back when the machine had 150 hours on it it was taken to dealer to fix a leak between transmission and transfer case. I would think they had to pull the transmission to fix that so the error would have been at the dealer's shop!