Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 51,575
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Have you checked the spools for leakage? Is there any evidence the cyls are bypassing at a very low rate?
Soundguy
Soundguy
RonMar
Elite Member
The valves that control the loader are called spool valves. Can you give us some more info about your tractor? What type loader? What fluids are you running in it? How many hours are on it?
Slow/poor performance could also be caused by some simpler things on these tractors.
1. Wrong type fluid for the temperature. The chinese 30wt oil that most likley came in all the resovoirs(including the hydraulics) of your tractor is too thick for cool weather operation. The pump is not real happy trying to draw thick cold fluid through that long suction line. The stock chinese hydraulic fluid should be replaced with something thinner. AW-32 hydraulic fluid is a good choice for cool to moderate climates.
2. The suction line is pretty long on these tractors, with a screen strainer located at the end in the resovoir. Any leak along this suction line can easilly induce air into the system and cause poor performance. One very likely culprit is the pipe union that connects the feedline to the suction strainer assembly. It is located on top of the resovoir under the front of the seat. Make sure all the fittings along the suction line are tight.
3. Depending upon the loader installed, there have been some problems with the quick connections that connect the loader control valve to the tractor hydraulics. The chinese quick connects dont always play well with other makes of quick connects. The check ball valves that seal the quick connects when disconnected, don't fully open when connected with other makes of QC and cause restrictions in the system.
CAUTION! Don't disconnect quick connects while tractor is running or attempt to run the tractor with the quick connects disconnected. When disconnected, the hydraulic fluid has no where to go and the excessive pressure has been known to blow pump seals, crack pump housings or damage pump shaft's and drive gears. This has been the cause of many hydraulic pump failures. Some cheap insurance to keep the connectors from inadvertantly being opened while the tractor is running is to place a large ty-wrap or zip-tie around the QC below the sliding collar. This prevents it from accidently being slid back to separate the connector.
Slow/poor performance could also be caused by some simpler things on these tractors.
1. Wrong type fluid for the temperature. The chinese 30wt oil that most likley came in all the resovoirs(including the hydraulics) of your tractor is too thick for cool weather operation. The pump is not real happy trying to draw thick cold fluid through that long suction line. The stock chinese hydraulic fluid should be replaced with something thinner. AW-32 hydraulic fluid is a good choice for cool to moderate climates.
2. The suction line is pretty long on these tractors, with a screen strainer located at the end in the resovoir. Any leak along this suction line can easilly induce air into the system and cause poor performance. One very likely culprit is the pipe union that connects the feedline to the suction strainer assembly. It is located on top of the resovoir under the front of the seat. Make sure all the fittings along the suction line are tight.
3. Depending upon the loader installed, there have been some problems with the quick connections that connect the loader control valve to the tractor hydraulics. The chinese quick connects dont always play well with other makes of quick connects. The check ball valves that seal the quick connects when disconnected, don't fully open when connected with other makes of QC and cause restrictions in the system.
CAUTION! Don't disconnect quick connects while tractor is running or attempt to run the tractor with the quick connects disconnected. When disconnected, the hydraulic fluid has no where to go and the excessive pressure has been known to blow pump seals, crack pump housings or damage pump shaft's and drive gears. This has been the cause of many hydraulic pump failures. Some cheap insurance to keep the connectors from inadvertantly being opened while the tractor is running is to place a large ty-wrap or zip-tie around the QC below the sliding collar. This prevents it from accidently being slid back to separate the connector.
