1989 Trooper II how to bleed hydraulic clutch system?

trooperii89trooperii89 Member Posts: 2
edited August 2014 in Isuzu

I have 1989 Trooper II.
I replaced clutch master cylinder kit and clutch slave cylinder kit.
Now the system is so full of air I am not sure what to do.
I tried brake like bleeding it won't work at all.
I heard about bench bleeding but I am not sure how to proceed.
I would like to hear a step by step already proven to work on this car method.
Also I got this power bleeder you can find advertised on the net
but it didn't work as advertized.
I suspect I can utilize it in bench bleeding so I would like to hear
from someone who already experienced all this.

Thank you.



  • atfdmikeatfdmike Member Posts: 414
    Here is what manual says:

    1989 Isuzu Truck Trooper II V6-2827cc 2.8L
    Vehicle Level Transmission and Drivetrain Clutch Clutch Master Cylinder Service and Repair Clutch Bleed

    Clutch Bleed


    NOTE: If air enters the hydraulic clutch system, it will cause clutch dragging. This procedure must be performed when reservoir has been emptied, or if system has been disassembled.

    Set parking brake.
    Check level of clutch fluid in reservoir and replenish as necessary.
    Remove the rubber cap from the bleeder screw and wipe clean the bleeder screw. Connect a vinyl tube to bleeder screw and insert opposite end into a transparent container.
    Pump clutch the clutch pedal several times, then hold pedal depressed.
    Loosen the bleeder to release clutch fluid with air bubbles into the container, then tighten bleeder screw. Do not release clutch pedal until bleeder screw has been tightened.
    Release the clutch pedal carefully. Repeat the above operation until air bubbles are no longer seen coming out of vinyl tube. During bleeding operation, ensure reservoir is kept full at all times. Reinstall rubber cap onto bleeder screw.
    If the reservoir cap diaphragm is stretched, re-shape it into its retracted position, then install cap on reservoir.

    1989 Isuzu Truck Trooper II V6-2827cc 2.8L
    Vehicle Level Transmission and Drivetrain Clutch Clutch Master Cylinder Testing and Inspection

    Testing and Inspection

    Make necessary correction or parts replacement if wear, damage or any other abnormal conditions are found through inspection.
    Before inspection, wash clean all disassembled parts in brake fluid and dry with pressurized air.
    Check the following parts, and replace with new ones as necessary.

    Cylinder bore and piston for wear and rust formation.
    Spring for weakening.
    Piston cups for wear and deterioration.
    NOTE: The entire piston assembly must be replaced if any of the piston parts are found to be objectionable.

    Clearance between master cylinder wall and piston
    Standard: 0.07 mm (0.0028 in.)
    Limit: 0.15 mm (0.0059 in.)
  • trooperii89trooperii89 Member Posts: 2
    Thanks for all the info.

    Here is how I solved my clutch bleeding problem.
    Since the clutch reservoir and bleeder on slave cylinder are
    not the highest points in this clutch system I decided to
    virtually raise/extend them with clear tube. Bleeding then was quite trivial and easy.
    I had a reservoir cap with a tube in it so I just attached
    it and held the tube up in the air. I got more clear tube at fish
    tank section dept store so I hooked it up to the bleeder on slave
    and held it up in the air next to the other tube
    so they both became the highest point in this system.
    Opened the bleeder on slave and filled the tubes with fluid until
    there was enough fluid so the fluid level was again above
    any other piece of this system and the same in both tubes.
    Basically you just make
    sure the system is full. Now you still have a little
    problem there is air in master cylinder so you pump it
    couple of times and there is still more air. Tapping on
    clutch pedal about half inch in and out will "bench bleed"
    the master cylinder without removing off the car. You will
    notice fluid jumps in that tube followed by bubbles till
    there are gone.

    That didn't solve my car problem. At least I know for sure
    I have no bleeding problem. I still have a very hard to shift clutch now. So I will probably take the car to a shop
    for transmission removal. I can't handle it myself.
    The hydraulic system pushes the lever about 3/4 inch by eye.
    So what can be bad inside. Bent fingers, bad bearing?


  • monstertruckmonstertruck Member Posts: 1
    I need help

    So the system on my 91 trooper got run out of fluid so Ive been trying to bleed it. I put on a new slave and I havent tried the methoedes stated obove but my question is when the system has air in it should the clutch pedel still spring back? if I put it all the way down to the floor it stays but if I go like half way it will spring back is that normal? I dont know what it is like when its all normal becuase the car was given to me becuase of this clutch problem.
  • cslemakercslemaker Member Posts: 3
    I have a 1989 Trooper 4-cylinder. Is there any way the actions involved in disconnecting the stuff connected to or near the valve cover, removing the valve cover, adjusting the valves, then closing things back up could cause an exhaust leak into the coolant passages to develop? I had a valve adjustment performed and immediately thereafter noticed the temp gauge doing funny things. Under the hood I found that coolant had filled the reservoir and sprayed the engine and underside of the hood. After trying a few other things (such as a new radiator cap), my mechanic pulled the spark plugs, pressurized the cooling system, and informed me that one of the cylinders then contained coolant. I find it very hard to believe that this was 100% pure coincidence (valve adjust & exhaust leak). Thanks for your opinion and answer to my opening question.
  • atfdmikeatfdmike Member Posts: 414
    Hi, I am no expert and have never worked on your particular engine. That said, in general, adjusting valve lash itself does not require draining the cooling system but heater hoses, water pump or radiator hoses may be in the way of removing the valve cover or gaining access to the engine, so if any cooling hoses had to be removed then air could have been introduced in to the system. You don't say why you had the valve lash adjusted, but if it was because the engine was running rough, I suppose it is possible that you had already developed a coolant leak (possibly at the head gasket) and roughness could be due to that. Another possibility in my mind is that IF (big IF) the cooling system was opened or drained and not refilled properly, then an air lock could have prevented coolant from getting to the head and the engine overheated, as evidenced by the erratic gauge action and then the expulsion of fluid. Once the air was expulsed, then the air lock may have been cured by cooling and refill of cooling system from reservoir. Problem that can occur though is that the overheat can cause warpage of head, leading to a coolant leak in to the cylinder. I think it could be tough to prove one or the other, but that is my opinion. Good luck.
  • cslemakercslemaker Member Posts: 3
    Thanks, Mike, for your reply. Reason for the valve adjust: in the course of a routine service including a tuneup, the mechanic discovered very low compression in one cylinder and recommended the valve adjustment.

    I don't believe that the engine seriously overheated during the initial coolant incident - the temp fluctuation I noticed was only a small, slow movement to just above and just below the center of the scale. I noticed it only because it was uncharacteristic - the needle formerly always was rock steady just below mid-scale.

    The fact that fluid appeared in a cylinder and that the breach was from exhaust to coolant suggests that the breach is very close to or at the exhaust valve for that cylinder. I would be willing to bet that the fluid cylinder is the one which originally had the low compression. My suspicion has been that perhaps a bolt holding the valve cover to the head was initially stuck, requiring some drastic measures for removal, or ditto for some bolt or nut which had to be loosened in order to adjust the valve clearance. In a sense the issue is academic at this point, but it is a factor in deciding whether or not I will continue to use this particular mechanic.

    Thanks again.
  • atfdmikeatfdmike Member Posts: 414
    You have an interesting point. If the mechanic drilled the water jacket trying to remove a broken bolt, then you could certainly wonder about his qualifications. As for the valve adjustment procedure, the rocker arm shaft bolts are checked for tightness, but do not have a very high torque. The valve lash adjusting nuts don't even contact the cyl. head so I don't see how adjusting them would damage the head/water jacket. Your conclusion seems plausible. One guys opinion.
  • swifteeswiftee Member Posts: 2
    Ive had a leaking hydraulic clutch in my 93 trooper for a while and finally shifting became difficult enough that I decided to change the master as everyone I asked recommended. I bled the system and the pedal remained slack so I replaced the slave. Still after bleeding numerous times I can get pressure under the clutch pedal. Ive bench bled the master, bled the damper and the slave and still cant get pressure! Help! I know this system is hard to bleed but this is the first time for me. Any recommendateions? One mechanic said I should just pump it 100 times in a row. Does anyone know of anything else I can replace? Are there other places that might leak that I can fix? How bout the damper cylinder? :cry:
  • steven2010steven2010 Member Posts: 1
    does anyone know about the cost for the repair of a transmission on a 1989 isuzu trooper??? :confuse:
  • atfdmikeatfdmike Member Posts: 414
    Well, welcome to the forum. You will get more help if you specify if it is an automatic or manual trans, whether it is 4WD or not, and what the problem was that brought you to the forum.
    Good luck.
  • sk8man1on1sk8man1on1 Member Posts: 1
    have you figured out how to bleed the clutch yet? I took my slave cylinder rod to a machine shop and had them add 2inch to it and that worked for me.
  • mtdelphiamtdelphia Member Posts: 12
    About $1800. It's cheaper to replace yours with a used one from a 'parts' car.
    Some break and others last forever.
  • mtdelphiamtdelphia Member Posts: 12
    edited October 2010
    I have had good results by simply cutting the clutch fluid line at it's high point on the firewall and installing a bleeder valve at that point. Put a piece of clear tubing over the nipple and open the valve. Have someone gently work the clutch pedal until no more air bubbles come out.
    Bleeder valves and compression fittings are available at most auto parts stores.
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