I have a cat 920 wheel loader.I replaced clutch disc and i repaired.because of its power has lost suddenly. i found the reason.there was a broken spring in the pressure control valve.so i put a new one.the problem is loader has no much power. other thing is transmission oil color is getting dark and temperature reaching high. can anyone give me a pressure setting catalog of a cat 920. please i appreciate any help. thank.
Seems like you aren't getting enough flow to the converter. Which spring was broken in the control body? Do you have an emailadress I can send a pdf to?
thank u per eriksson. yes my email is [email protected] or [email protected] the spring which was broken is in the modulating relief valve.it is outside spring. i have D4E power shift transmission testing and adjusting catalog.I'll mark the spring and send u.
thank u Per Eriksson. I got your mail and sent u D4E catalog.I'm connecting with this forum and I'll write the result.
today i check pressures pump 3.47kg/cm2(g/c minimum) 10.2kg/cm2(g/c max) speed clutch primary setting 3.5 kg/cm2 direction clutch 1 kg/cm2 (g/c minimum) 7 kg/cm2(g/c max) inlet to the torque convertor 2 kg/cm2 (selector lever in neutral ) 1 kg/cm2 ( selector lever in 1st forward) what should i do. please i need more help
I would take the pump apart and check it for wear.
thank you Per Eriksson. today I'll try to check the speed clutch pressure g/c lever at max setting.
the oil pressure of speed clutch (g/c lever at max) is 10.4 kg/cm2. I like to check lubrication relief valve.please can you tell me where it is the location.
Lube oil is the return from cooler/torque converter, doesn't have any relief.
In the catalog that you have sent me page 2 of 8 shows it by number 8 called 'lubrication relief valve' other thing why dose pressure of direction clutch go to 7 kg/cm2(g/c at max). it should be 3.5 kg/cm2.so i think there should be a problem in the pressure control valve. please could you explain me.
No, direction clutch pressure shyould be 3,5 bar LESS than the speed clutch pressure so about 15bar at idle. You either have very bad flow from the pump or a big leak in the controlvalve. since all pressures are too low.
thank you per eriksson. I'll disassemble the pump and send you its images.
Dear my friend. I did a little bit different experiment. I keep the engine rpm at about 1000 and close the tap step by step to increase the pressure .but I couldn't get the pressure to bar 5 even by closing the tap full.after that i removed the pump off and disassembled.
This is the method of pressure testing.
What do you think about pump.I'm so worth your opinion.
This is the wooden plug which I used to block the flow from filter to transmission control valve.
This is after blocking the line . then I installed the filter with those 2 lines
I had to take this valve off and installed the line with tap.
Today I checked the line from pump into the filter.I applied air pressure into the inlet port to the filter. And blocked outlet port to the filter.
At last I found the reason.there was a crack in that line.but I can't see it. because it is inside of the transmission.So I blocked that line
Those are the plugs made by bronze.
So I made a new line from pump to the filter outside of the transmission.
OK see you tomorrow .
I think you need a bigger hose and connectors, it looks like a 1/4" ? But for troubleshooting it should work.
today I checked the pressures P1 speed clutch primary setting 3.5 kg/cm2 (g/c lever at minimum) P1 speed clutch 19 kg/cm2 (g/c lever at mini) 20 kg/cm2 (g/c lever at max) P2 direction clutch 10 kg/cm2 (g/c lever at mini) 10 kg/cm2 (g/c lever at max) P3 inlet to the torque converter 3.5 kg/cm2 (g/c lever at max) P2 direction clutch pressure 10 kg/cm2 is not the maximum pressure.the gauge that I used it has only to 10 kg/cm2. pleas can you tell me what happen to the P2 pressure.Is there a fault in the control valve.
Remember that the P2 pressure should be 3,5bar LESS THAN P1 so it should be about 15,5 at low idle and 18 at high idle Use the other gauge with a higher range to check P2 also, I'm sure it will be about these values. And check converter outlet pressure also
thank you my dear friend you're correct. I understood. I have got only 3.5 kg/cm2 and forgot LESS THAN the pressures are 15 kg/cm2 at low idle and 17 kg/cm2 at high idle. tomorrow I'll check converter outlet pressure also.
Per Eriksson I repaired the starter motor and started the loader. but some time it didn't move. so I decided to change the converter oil.I found some metal pieces with drained oil. Now I'm going to disassemble the converter.I think this parts are the reason for the problem. Please further I need more help. Thank you so much Per Eriksson.
This is the line that was cracked.
The line was cracked.
The line had been fitted to the housing with a look sleeve.there was a groove in side the hole.
HAPPY MERRY CHRISTMAS .. I made a new line.
after finis