I have a 345BL Cat (4SS011287) with a Genesis 1000 shear attachment. When the hydraulic oil warms up the shear loses speed when closing and cutting force. The shear head was supposedly or at least advertised on Machinery Trader as completely rebuilt when I purchased the machine over a year ago. I flew to the dealers location to look at the machine and do a quick test run to check the obvious things you would look for on a used excavator when purchasing one like engine blow-by, sudden compression in the radiator, major oil leaks, noises, roughness in the swing bearing, pin wear, ect.. They didn't have any scrap steel to actually test the shears cutting ability so I couldn't test the actual cutting force but I was told by the salesman at the dealer (Sargents Equipment in Chicago Heights, IL) from whom I purchased the machine that the machine was "run, brought up to temperature and tested and everything was fine". After purchasing and receiving the machine I reinstalling the shear head on the machine and it was very apparent after running and cutting with the machine for only 15-20 minutes there was a big problem. They sent one of their service techs to look at it and to fix a major leak which had developed on the shear cylinder and he told me the shear cylinder needed to be rebuilt because oil was bypassing the piston. He put gauges on the pump which as the oil warmed up the pump hardly built any pressure when closing and dead ending the cylinder of the shear. But when he would dead end the cylinders for other functions like boom up both sides of the pump would go up to 5000 PSI. The dealer then wanted me to remove the cylinder, pay for all shipping cost of getting the cylinder to and from their location and pay for their labor costs to have them rebuild the cylinder. I would also of course have to reinstall the cylinder at my own expense. How nice of them was that? After some heated arguments on the phone I told them they could go *&*# themselves thinking I was going to pay an estimated $2500.00 in labor costs to have them rebuild the cylinder on a machine which they had just told me they had tested and that the machine and shear had no problems, plus shipping costs. I guess that "as is" clause on your purchase agreement means just that, even if they specifically tell you there is no problems because you can't test a function on a machine yourself and they won't even stand behind their word when they tell you it is "OK". Oh, a seal kit did show up in the mail about three weeks later. Not sure if they felt guilty about telling me the machine had been tested and it was OK or if me telling them I would tell everyone I talk too what kind of service they provide to someone that just spent $197,000.00 on a used piece of equipment that they told me had no problems and had been advertised as having the shear head completely rebuilt, which they later admitted to that it wasn't rebuilt. Anyway enough of my rant on to the problem. When the oil is cool the shear jaw will close fast and will cut through just about anything you can fit in the jaw. As the oil warms up the shear jaw starts to close slower and slower and the cutting force gets less and less until the shear will hardly close or cut through a piece of small pipe. After the oil warms up and I loose most of the cutting force if I hold the control lever over to close the shear jaw until the shear doesn't have enough pressure to cut anymore and I swing the machine left or right at the same time the shear circuit seems to build some extra pressure and will start to cut again. It is no where near the cutting force it should have but it does build extra pressure and I can usually get the shear to cut though what I'm cutting if it isn't to big and thick. Which makes me think the oil is not bypassing the piston like the service tech from the dealer suspected. If the oil was bypassing the piston why would the shear start cutting when I swing? I would also think that the shear jaw would still close at a faster rate even if some oil was bypassing the piston when the jaw is free traveling closed. It takes hardly any pressure to close the jaw when it is free traveling and I don't think enough oil could bypass the piston to affect the speed when the shear jaw is just closing on it's own. I would imagine the two pumps are putting out well over 100 gallons a minute and you couldn't have that much leakage around the piston to almost not move the jaw even if there were no seals installed on the piston at all. I can put the jaw on the ground and open it when the oil warmed up and the jaw has enough force to pick the front of the machine up off the ground, so I know the shear cylinder is getting plenty of pressure in the opposite directions. I have also noticed that when I use another function on the machine like boom up it will sometimes cause the shear jaw to close by itself even when I have the control lever which would normally close the jaw in the neutral position. This I don't think should be happening and I don't think oil bypassing the piston would cause this problem. The circuit that closes and open the shear jaw is the circuit that would normally run the dipper or stick cylinder. The stick cylinder is now connected to the valve where the bucket cylinder is normally. This is done I believe to get both sides of the pump to pump oil to the shear cylinder for speed since the shear cylinder is so big. The control lever that is used to control the jaw on the shear is the lever that would normally control the bucket roll in and out on a normal excavator. I would imagine the pilot pressure lines were just swapped on the control valve to switch the functions of the control levers. There is also a regeneration valve on the shear cylinder itself which puts oil from the rod side of the cylinder into the opposite side of the piston to speed up the closing of the shear jaw when it is free traveling (not cutting). According to the manufacturer this valve then closes when the oil builds to a certain amount of pressure when the shear jaw stops when coming into contact with what ever is being cut. I have talked to the shear manufacturer and they do not suspect that the regeneration valve on the shear cylinder has anything to do with my problem. The manufacture of the shear suggested that I replace the pressure relieve on the valve bank thinking perhaps that was the cause. Which I did, that has not made any difference in the performance of the shear cutting force. Should I start by checking my pilot pressure at the valve bank which operates the spool which closes the shear or perhaps swapping the pilot lines from one spool to another to see if the problem moves or could it be something else? If you need any more information or pictures let me know. TIA
I totally agree, your problem is on the machine, not the shear. The machine have a regeneration valve for the stick function as well and I would take a look at that first, seals on that spool is known to go bad all to often and causes all sorts of problems, sometimes sending pump pressure into the pilotcircuits. Not fun to check since it is placed on the bottom of the valve bank so you need a good vacuum on the tank if you dont fancy an oil shower.... Below the stick spool in the left valve bank, square cover with four bolts, remove the cover and you have a spool you can pull out that should have 5 fresh seals on it if all is well.
I am by no means a expert but I would check the output pressure of the pump hot. A when a pump gets hot the oil bypass in a worn pump fairly easy . I hope I am wrong and you find something easy.
I will take a look at the regen valve on the machine and see if all the seals are intact. Thanks
I agree with xcmark. Get a pressure reading, sounds like a bypass of the pump or valve for the shear. You can also test pressure at the sear. I just had this same problem with a 980 loader and the bucket dumping on its own.
All other functions of the machine seem to be fine. Boom has plenty of power to pick the machine up off the ground. Travel is fine. Swing works well. Also the pump pressure was checked hot and while dead ending the boom cylinders up, both sides of the pump produced 5000 PSI so I don't think it is a problem with the pumps getting weak when the oil gets hot. I hope I find something easy too. The biggest thing I don't know about Cat machines is if there is any electronics that would effect the way a certain circuit of the valve bank would act. It seems my Hitachi has enough electronics on it that usually when you have a problem it is related to a sensor or switch gone bad. Thanks for your reply.
I don't see the pumps or relief valves causing this since he mentioned that sometimes it will move on it's own or appear to gain strenght when using another function at the same time? which relief was it that you replaced earlier? The 2 reliefs for extend and retract on the "stick" circuit are identical and can be swapped.
I replaced the relief that was on the top side of the valve to the right of the block that has the four bolts on it. You can see the relieve is nice and shiney and not to rusty. The steel tube that crosses the picture is for the swing. The hose to the left of that is what goes to the shear cylinder. I think this is where the stick cylinder normally hooks up. Sorry I couldn't get a bigger picture but the forum only allows for 640 X 640 pictures and had to crop it down.
For a bigger picture you can click on this link. http://i633.photobucket.com/albums/uu59/EX400LC-3/IMG_0012.jpg
did the problem happen when you move shear only and how about if you move combination implement ?
The shear is lacking pressure all the time when the oil temp is warm. It doesn't matter if I use another function the shear doesn't work any worst than what it does if I'm only trying to cut. It's only when I swing left or right when I get a little boost in pressure on the shear which will help it to cut, but the pressure is still not what it should be. The heat wave has broke and I'm planning on taking the block off which has the four bolts on it that you can see in the picture and examine if the seals are intact or not. I haven't had time and it has been to hot to mess with to see if there is another block with four bolts on the lower side of the valve as suggested earlier, but I'm hoping not. I don't really like standing on my head trying to take this stuff apart. I will let you all know what I find if anything as far as the condition of the seals. If these seals are bad are they something that is available at a local hydraulic shop or is it best to order them or the entire part from Cat? TIA
Srapper, your problem sounds like a pilot system problem to me, but hard to say without being there. The pilot system plumbing on these machines is VERY complex, with a bunch of hoses, check valves, resolver/shuttle valves, pressure switches etc. If the installing dealer had to change the plumbing on the pilot system when they installed the shear, they may have caused the problem you are having. It sounds like you may need professional help. If you are on the east coast, contact TOM V (forum member, and shear expert) (860) 919-4439, his company is Veronesi welding & repair. You can check out his operation on this forum under "shop talk", thread name "some work pictures". One other bit of advice I would offer is to operate the machine briefly in backup mode, when it is hot and acting up. Backup mode will eliminate the computer from the machine, and is a good troubleshooting tool. Backup mode is achieved by using the two toggle switches hidden in the back of the right arm rest. Whenever I am troubleshooting a problem on an excavator I do this. Hope this helps.
Thanks for the reply. I will try that if the new o-rings don't fix my problem. I pulled the block with the four bolts off last night. I pulled the barrel and spool which looks like a big check valve out of the main valve body. The O-ring which seals the barrel inside the valve body was in pretty bad shape and the back up washer was broken. One of the O-rings which seals the top block to the inside of the barrel is also questionable. The only O-ring that looked OK was the one which seals the top of the block to the valve body. Of course if that one was bad I would have had oil leaking out of the valve body which would have been pretty noticeable. I picked up some O-rings and back up washers at the hydraulic shop this morning. The back up washers that I removed were Teflon and the hydraulic shop didn't have any Teflon washers in stock so I got regular rubber or plastic ones instead. Does anyone think this will be a problem if I don't use Teflon washer?
I think you'll be okay but I'm doubtful this really is your problem, that check valve is on the "wrong" side of the circuit and problems with it as I see it would only keep oil from returning from the jaw rod end when trying to close causing a massive buildup in pressure on the rod end until the relief opens, but stranger things have happened for sure.... You really should take a deep breath and check out the regen valve on the lower side as well. The seals on that is not ordinary rubber orings but some teflon or viton stuff, 3,5x31,7mm
Heck I was thinking what I took apart was the regen valve. I kind of looked at the lower side of the valve and didn't see anything that has 4 bolts holding a cover on. But it is pretty hard to see down there. I guess I will have to take the cover off the bottom of the machine so I can get a good look at it from the lower side. That O-ring was pretty bad and needed to be replaced anyway so at least I don't feel to bad. If I don't see the cover held on by the four bolts on the lower side of the valve you are talking about I will try and take a picture and post it so you can help me out. TIA
Sorry to do this but i must be retarted.... new to site and would like to start a new thread and cannot seem to figure it out !!! Your help is appreciatted !!!
There is a button near the top of the page on the left side that says "Post New Thread" Make sure you are in the forum you want like this is the Excavator forum. There are also forums for Dozers, Graders, ect. You can try clicking on this link also if you want to start a new thread in the Excavator forum and it might take you to the right page.
Thanks for your help !!! Just signed up and I guess I am awaiting activation....sorry for the interuption.....thanks again !!!
You need to activate your account by going to your Email address and clicking a link there. Good luck.
OK so I took the cover off on the belly of the machine and took a look at the under side of the valve. Since I don't know which part of the valve is the regen valve I thought I better take some pictures and post them here before I take apart something else that I didn't need to. It looks bad enough getting this apart I don't want to have to do it twice. Funny how they missed that part of the machine when they were power washing. They seemed to get everything else pretty good. Can someone let me know which part of the valve I should take apart. I labeled the two parts of the valve that were under the hose going to the shear. A is the furthest to the left hand side of the machine.
does shear cyl have regen valve, ussualy regen valve instaled on lines boom and stick, i read your firt post that you have replace relieve valve, just make sure that is for rod end or head end ? And did you have adjust this valve ? The Spec about 5050 psi
This one,
Good thing I asked. I would have taken "A" apart. I never even noticed that cover up in there when I looked at it.
I took the regen valve out. I don't see any seals on this thing at all. I also noticed some scratches on it that I took a picture of. Can you let me know if there is supposed to be seals on this or not and if you think the valve is salvageable or if I should just buy a new one. Also if anyone has a parts breakdown of the valve I would really appreciate it. I can PM you my Email address if you need it.
I also noticed some junks of black crap that looks like plastic in the grooves of the regen valve. Not sure if this is what is left of the seals if there were supposed to be one or if this is coming from somewhere else.
There you have it, you should have seals in all five grooves..... I wouldn't worry about the marks since they are on the outside and don't have anything moving against them, just try to smoothen them out a little so you dont damage the seals when putting them on. Make sure the spool fits nicely in the bore and moves freely. Parts breakdown View attachment Regen valve.pdf The updated replacement version that have better seals, pricy but you could get just the updated seals. View attachment Regen valve updated.pdf
Hey Scrapper, sorry to highjack your threasd again. Received email welcoming me, but no link. Tried clicking on contacts to get ahold of the administator, just gives me an error. Any help would be apprecaited ! Thanks !
I don't think you would be able to post if you didn't activate your account. Not sure why you wouldn't be able to start a new thread. I believe I started my first thread right out of the gate with no post count when I had a problem with my EX400. Some forums require you to have a certain number of posts before being able to do certain things on the forum. That might have been changed since I joined too and was the reason I could start a new thread and you can't. You might want to go ahead and create a new account with a different Email address and see if that fixes your problem. You can make up a new Email pretty easy using Hotmail or Gmail. Good Luck.
Thanks Per Eriksson for the help and the parts breakdown. That is really something that all five of the seals were completely gone. I can see how oil could go from one port to another and mess this thing up with no seals. The spool moves freely inside the bore and the spring is not broken so hopefully it will be alright. I'll take some emery cloth and smooth out the scratches before installing the new seals. I have five new seals on the way from the dealer, $3.00 each for the seals plus shipping, should have them on Tuesday morning. The new replacement valve would be just under $500.00. I will let you all know how it turns out once I get the valve reinstalled back in the machine, hopefully on Tuesday.
nice thread
Scrapper, those 4 black particles in the photo above. It's difficult to tell from a photo but are they metallic or non-metallic..? If they are non-metallic then how hard are they..? In other words can you crush them with a pair of pliers..? If you can they are likely what's left of the missing seals. Another comment regarding O-Rings that you posted earlier. Those O-Rings that have a backup ring (the white Teflon Ring) should really not be installed without that ring otherwise the O-Ring will tend to deform under pressure and start to leak before very long. A black rubber washer will not work reliably for long - the hydraulic shop should have told you this. O-Rings in this type of application need to be 90 Duro-rated nitrile rubber (not 75 Duro silicone rubber under any circumstances), that's the only material that will stand up to hot hydraulic oil for any length of time. If your local hydraulic shop cannot supply nitrile O-Rings or give you a blank look when you ask for them, head straight for your nearest Cat dealer. I'm not 100% familiar with your 345 but I know some exacavators use metric-size seals in the hydraulic systems. The difference between inch sizes & metric might only be a few thousandths in some cases but it'll be the straw that breaks the camels back.
Great thread! Enjoyed following this one, hope everything works out and sorry to hear about the crappy company you had to deal with while buying this machine!
Received the 5 new seals on Tuesday. Total invoice including shipping costs $22.40. I filed the scratches on the valve, greased up the seals and managed to slide them on valve into the correct grooves, took out the plug on the cap so I could slide the valve down into the cap (if I didn't air pressure built up wouldn't allow me to slide the valve all the way into the cap) and then greased up the whole regen valve and stuffed it back up into the main valve and tightened the four bolts. A piece of 1" pipe about two foot long worked good for pushing the regen valve back up into the main valve. It's a tight squeeze up in there. The whole job didn't turn out to be half as bad as I thought it was going to be when I first looked up at the under side of the main valve. I started up the machine and moved the jaw on the shear back and forth a little bit and then checked for leaks around the reinstalled valves, which there were none. I then grabbed a cold beer out of the refrigerator and turned up the RPM's on the old CAT and proceeded to try out the shear. Holy Crap, this thing will cut though anything now. I can cut though stuff I couldn't cut before even when the machine was cold. When the guy I talked to at Genesis said "that shear should go through two or three I-beams at a time without any problem" he wasn't kidding. So I'm thinking OK the hydraulic oil will warm up and the shear will start losing pressure soon. Well it was over 90 degrees outside and it actually took longer for the oil temperature to come up than it did before when the outside air temp was much cooler. I would imagine this was because the hydraulic oil bypassing the regen valve before generated a lot of heat which is not the case now. The oil temperature got up to three bars on the gauge and the shear was cutting good, four bars and still slicing throw anything I could fit in the jaws. Hats off to Per Eriksson for diagnosed this problem to the T. I just wish Sargent's Equipment would have spent more time testing this machine before they sold it and not lied to me when they said they ran the machine up to temperature and tested everything and the shear works just fine. A few seals and an hours worth of labor wasn't worth losing a potential repeat customer. I will never buy another piece of equipment from Sargent's Equipment after what I experience with this one. I'm just glad I didn't send the shear cylinder to them to have it rebuilt. I would have had $2500.00 plus shipping costs invested in that and it wouldn't have fixed the problem. Which I'm almost sure they wouldn't have reimbursed me for when it turned out to be 5 O-rings that cost $15.00. Thanks for everyone's help. I'm glad you enjoyed the thread. I'm hoping to make a video of the shear in action and when I do I will post it here for everyone to enjoy.
Well done
Excellent.