This may have been covered somewhere already but I cant find a good step by step procedure to properly flush the cooling system. I ordered a new expansion tank and need to flush the system clean. I understand the procedure for flushing the system but havent found anything to guide me through step by step on the LR3. I have the 4.4L HSE.

Any help and or advice would be greatly appreciated.

Thanks

 

Land Rover Workshop Manuals > LR3/Disco 3 > 303-03B Engine Cooling- 4.4L > Cooling System Draining Filling And Bleeding

 

Yep, the procedure would be the same as draining/filling/bleeding but multiple times for the flush and rinse then re-fill. Good time to do it.

 

Alright, so I drained the system according to the directions. I filled the tank with water, ran it for a bit. Drained it again, water again. Did this 3 or 4 times. Took a long time to get rid of all the old coolant. Drained all the water (I hope) and filled with new coolant. Now Im getting no heat, (possibly air in heater core?) and I have a coolant leak from under the new expansion tank.

 

No heat is likely due to air in the system meaning it's not completely bled/filled. Make sure you bleed it properly. When I've replaced coolant or cooling components...the process takes a while....a number of cycles of getting up to temp, bleeding it, adding coolant, repeating.

Whenever heat blows cold it's often followed by a rapid increase in coolant/engine temp (not good).

 

WHATEVER YOU DO!!!!....

Don't forget the top secret bleeder under the engine cover around the thermostat / throttle body area..

Unfortunately I must also mention that if you haven't touched it before, there's an 80% chance you'll break it when you touch it. It's a plastic POS. I just replaced mine with a brass 1/8" NPT tee with hose barb fittings on either end and an NPT plug in middle to bleed. $10 total at ANY auto parts store and is totally indestructible. Or you can pay $20+ for the plastic LR one.

FWIW I ended up screwing another barb fitting into the plug port on my new bleeder and attaching it to a water tank that I'd fill to aid in bleeding it. That "top secret" bleeder goes to some random areas of the engine that don't see much coolant flow apparently. I ran the motor forever and couldn't get a solid stream of water out of the tee till I did this. MAX heat of course, and I believe the LR manual requires multiple heat cycles and engine RPM ranges to complete a full bleeding cycle (what kind of BS is that?!) I'd rev the engine slightly (2200rpm ish) and eventually I got a solid stream when it was bled completely and up to a high enough temperature. THEN I put the NPT plug in and I was good to go.

FWIW I've never heard of anyone else doing it quite this way but the science behind it seems sound enough that I can't think of a single argument.

...besides, if I can bleed a DII cooling system, I can bleed any cooling system on earth.