Service Advisory 9:
18-28 HP Jinma Tractor Inline Filter Modification.
Approximate Time Needed for for Mod. is 1 hour.
This Advisory contributed by Kevin H.

In line filter modification  ( Always Wear Eye Protection When Working on Tractor)
This filter modification is only a suggestion to prolong your tractors hydraulic system. This is not an official factory modification. Improper installation and or failure could cause damage to the tractor and or persons operating it. When in doubt contact a professional mechanic.

Materials needed:
- Universal Hydraulic Filter Assy. “Available from Parker, TSC, Northern Tool.  Costs $13.00-$25.00.
- (2) 3/4x5/8 NPT to Barbed fittings. Costs $4.00
- (4) Heavy Duty Hose Clamps available from Napa or other Auto parts stores. Costs $4.00
- 10 inch piece of band steel “From tractor crate”
- 2ft of 5/8 low pressure/return hydraulic hose, “Not Heater Hose”.  This hose can be purchased   from any auto parts store and or hydraulic shop. Costs $5.00
 

1.Disconnect hydraulic return pipe on the left side of the tractor at banjo fitting under seat (fig 1)
2.With tubing cutter, cut a 6 to 8 inch section of the pipe between the banjo fitting and where the 4wd lever is. “ There should be 6 inches of pipe to work with on the banjo fitting side.”
3.Mount the bracket, “band steel” on the forward left seat attachment bolt.(fig 2)
4.Install filter assy, fittings, hoses and clamps.
5.Position filter assy by bending bracket to desired position.
6.Position return line pipe on both sides to clear the 3pt hitch arms and 4wd lever.
7.Leak check under max RPM with moving the power steering and 3pt hitch, “this will put a high amount of hydraulic fluid through the return line.”
 

Note:  High-pressure hose may be used but it is very difficult to work with and hard to find in 5/8” I.D. size. Hydraulic return hose and or Farm/Fuel hose should work fine for several years.

Warning: DO NOT INSTALL FILTER ON PRESSURE SIDE OF THE HYDRAULIC SYSTEM! DAMAGE TO THE FILTER AND SEVERE INJURY MAY RESULT!

Note: This information is based on my experiences and should not be considered an official maintenance manual. This information is to be used as a guide and reference only.

Warning:  Use extreme caution when performing this procedure. Always secure both halves of the tractor on safe jack stands and use a quality floor jack that will support the tractor and roll freely. Never work alone, have a friend help out or stand by for safety purposes.

1.Remove hood; mark all electrical plugs and wires to the gages and fuel sender to prevent confusion when reassembling.

2.Unplug wiring harness at the rear lights and clutch and brake switches. Set entire wiring harness on top of the engine and secure so it is out of the way.

3.Unhook decompression linkage. (Fig 2)

4.Unhook throttle linkage. (Fig 1)

5.Disconnect hydraulic pressure and return lines at the Hyd. Pump.

6.Remove to power steering hydraulic lines at the P.S. valve. (Fig 3)

7.Remove the main fuel supply and return line and secure. (Fig 1)

8.Remove Drive shaft by loosening the two clamps that hold the rubber boot between the two shaft covers. Slide the covers towards each other, exposing the driveshaft couplers. Tightly grab the drive shaft and push it towards the rear of the tractor compressing the spring on the shaft to uncouple from the front axle. Remove the drive shaft by pulling the shaft forward after front coupler is free. (Fig 4)

Note:  There are 6 ball bearings for each front and rear coupler. Be careful not to loose these. Use axle grease to hold the ball bearings in the coupler when re-installing drive shaft.

Warning:  Use extreme caution when separating tractor halves. Have a friend help stabilize the engine as you pull on the floor jack to separate the tractor halves. The engine will rock on the front axle and could cause the jack to slip out from under causing serious damage to your tractor and person.

9.Support the tractor front and rear. Support the rear using two jack stands. Support the front using a floor jack directly under the engine. Remove the bell housing bolts, there are bolts behind inspection plates, if plates still installed.  Separate the two halves by pulling the floor jack and front half of the tractor from the rear half.
 

10.Remove the clutch assy by removing the bolts securing it to the flywheel. (Fig 7)

11.Pay close attention on how parts are stacked in the clutch assy. Remove and replace parts as necessary.

12.Install new clutch assy to flywheel. Align PTO disk between clutch assy and flywheel as you are tightening the bolts that secure the flywheel. Use clutch alignment tool or sand a broom handle to fit inside the pilot bearing.(Fig 7)

13.Refer to the Dual Stage Clutch adjusment procedures for adjusting the clutch. “For both new disks and springs, adjust 21mm nuts until nut compresses spring and nut contacts the pressure plate. Adjust arm adjusters by feel, usually 1 to 2 threads will be visible on the arm pull fitting that arm attaches to. (fig 5)

14.When mating the two halves, you may need to turn the flywheel and have the tractor in gear so the input shaft to the transmission does not turn. Use caution when mating the two halves together.

15.Reverse the removal procedure for the rest of the reassembling of the tractor.

The following information is based on my own experiences during the adjustment and replacement of Jinma Q284 Dual Stage Clutch. This information is to be used as a guide and for reference only, not to be confused with a factory maintenance manual. When assembling your new tractor always check the adjuster bolts for equal adjustment by counting the visible threads and or gap measurements.
 

1.Adjustment of the dual stage clutch may be achieved by removing the cover plates on the bellhousing or loader mount if equipped with front-end loader. If you find clutch material “black or burnt fiberglass or cloth like material”, your clutch may soon need replacement. This adjustment may still get you some usage before total failure.

4.Do the same for the other two adjusters.

NOTE: The spring under the adjuster nuts may not be visible after your adjustment. This may mean some of the clearance is excessive due to clutch disk wear. This adjustment will most likely stop your clutch from slipping but you will have less clutch pedal due to the adjustment and clearance change.

Note: Always keep approximately 1/16 of an inch clearance between the pressure plate arms and the release bearing.

6.Make the adjustments to the pressure plate finger or “arm” adjustment bolt 1 to 2 turns at a time.

7.Drive the tractor and test your clutch after you finished with the first adjustment. If clutch feels like it is getting better make another slight adjustment checking after each attempt. You may have to experiment to find the perfect adjustment. Make sure all clearances are the same with a feeler gage between each adjuster. (fig 4)