Whn I first start the 3cx it's still cold the hyd work a little faster that's but still very slow and weak as the engine gets more worm the hyd get weak and slow as it needs 50+ gas for it to do some work the front and the beck ,I got the hyd pump tested its good , I checkd the hyd filters as I only found the the one In the engine bay in the tube and the tube was empty there was no filter in the tube not shore if that could be my problem , or another thing as it didn't have a hyd filter maby the valve body's got dirty and maby they need to be cleaned out ? If eny one could help thanks.
Hi How has the hyd pump been tested has it had a flow meter putting on it and has the machine main pressure been tested as this is going to be the starting point .when you say filter in the tube you mean the big metal canister on the bulk head if so you should have a filter to protect but i cant see it would make any diference as long as you have oil in the system not ideal to run with out mind. If you need pressure settings for the mrv i will dig them out for you .it does sound as if you main pump is getting weak ,when you dead end a service does the engine come under load and black smoke . Jeff
The pump got tested as he open the pump up and head a look at it by eye he did not pressure test the pump , yea the filter located in front of the fuel tank but ,I got the work shop manual so got all the info thanks eny way for that, what did u mean by the last question didn't understand it
Hi What it means bring say the dipper all the way in and hold it what does the engine do does dog down and come under load? You can also try full or 3/4 revs and using boom (boom on the ground starting postion) lift boom up and then nock back the revs to half and see what happpens to the boom if it stops i would suspect pump flow. But please have a flow test done on the pump as although a visual inspection has been carried out you need to start with correct flow. If you dont have oil restriction entering pump meaning internal suction strainer / filter in tank need to undo plates on side of hyd tank . I have had issue with what we call project 8 machines cracking front loader spool blocks and if you listen to a good one and then a cracked internal one you can here a hiss and it does give you a similar problem but not had any proj 7 do that. Flow test first and get a flow figure if you put the flow meter in between pump and spool block it will tell you pump only but be careful as you are not protected by mrv on the machine .
Hi Jeff yes the engine dogs down when I bring the dipper in (comes under load) . I done the 3/4 gas with the boom and the boom just slows down . I was shore that the guy had all the tools to test it I don't 150km one way to get the bloody thing tested and then he didn't have have the tool for the flow test as the flow test will tell you 100% if its good or not . I cleaned the hyd tank and I found only one hyd filter that for the power steering pump and no other filter as I thought there will be a hyd filte some where in front of the pump but can't faint any filters except that 1 for power steering , and also when I operate the dipper by the handles the valve bloody makes like air like on every handle operated ?
Hi Have you taken the round plate off on the side of the tank as from memory there is a filter in there which is on the suction side of the main pump.will need to drain tank down first. It sounds like you have a cavitation problem is the oil in the tank look air rated like its got bubbles in or like the froth on your beer as this would be a good indication as to cavitation. The suction hose from the hyd tank to the pumpmake sure you dont have any leaks from there as that can suck air in ,the thing with running the machine with no hyd filter in will eventually let dirt back into the suction side of the hyd system causing problems.your only way forward is a flow test on machine between pump and valve front loader valve block and test.next test between carry over pipe between front block and rear hoe valve block to see where you are loosing flow you might find that you have a fracture inside the loader valve block causing the oil to flow into the return line.Have you managed to put a pressure gauge on the hyd system to see what you have. has you machine got extra dig and if so is that ok. Jeff
I got the hyd tank drained and got the both flares of one and the other side and there is no sighn of a filter in the suction pipe or to do eny thing with it , yes I have little bubbles her and there in the oil , I can't find a the tools like the test gauge to test the pressure eny where her , or maby I could make one if you can tell me what kinde of gauge do I need , not shore if the ones like on the air compressors would do ..? Thanks for helping out Jeff
Hi Looks like things are against you slightly , MRV pressure depending on serial no between 180 bar and 228 bar or 2600 psi and 3300 psi pump flow should be single pump only 91 ltrs min pump flow double pump 81 ltrs main part and smaller pump approx 45 ltrs min has your machine got a small steel pipe on the front loader valve block if so this has got a two stage releif valve and could be dumping pressure back to tank? There is from memory a anti cavitation valve in rear valve block under the spool on the left when sat operating the rear end need to remove spool dust cover top and its under there a poppet and spring check for damage to poppet or seat. Also not having a return filter in the system does not help with dirt going back into the pump round the system and then back to pump and so on slowly destroying the system. as far as an air gauge not every tried it but thats your call and your safety.
Hi I know ay it's some thing little just got to find what is the prob I hope I will your help is priceless as I did learn much yes I got a lil pipe on the front valve block the pipe is located on the front and it go's from top of the face valve block to the bottom face of the valve block and it looks basically like a metal brake line. Is there another name for the cavitation valve ? What did u mean by the poppet ?
Could the air bubbles in the hyd oil be a issue with my problem
A poppet would be like a valve seat so as oil would seal similar to a valve in the engine. Air bubbles wont help you. Have you always had this problem or is only just started ?
So the poppet is in side Of the valve block but i get to it se i remove the dust cover am i right , but could the air bubbles do enithing with my problem , my old man got this jcb cople years ago and he Was not there so he Was Been nice and lent it to a friend as he knows how to work with it and that guy was working with it for like a year doing who know what,when i got home with my old man i strated working with it and it Was a little better to work with than now but it Was still slow ..i have cople leaks on the valve brocks front and beck not would you know if that could be making it weak when operating it
I think you need to obtain some hydraulic pressures readings as its only guessing what might be wrong and as yours has the small pipe on the front valve block you have a h p c o line or it means you have a high pressure carry over line to the rear valve block and must be balanced. This is how the mrv that i think you have works . I hope this might help understand how it works and what is controling the pressure in the loader valve block you may find you have an inbalance on the mrv or if you look at pictures last two it shows the location of the o rings which you might find one of them damaged or split but you do need to see what pressure you have first.
Ok il have a look jeff thanks alot for Your help
Hi guys can eny one tell me wich hose should go where from the hyd pump on the jcb 3cx 87mod , it's a tail shaft driven hyd pump
Was yours a single or double pump if its a single it should go to front loader valve block and onto the rear valve block,if its a two section pump you might have aux valve block to run a breaker or hyd tools from the machine but should run aux circuit like slide on rear boom if you have it or aux service and will combine flow to the rear valve block from memory been a while though. Pump 1 being closest to the shaft