• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Back flushing a 87', closed loop Renix

JaysXJ

NAXJA Forum User
Location
Louisville, KY
Newbie here. This is my very first post. I recently scored an 87' 2-door Sport with 4.0L and the towing package with D44 trac-loc and 100 amp alt for $150.00. Thats right, that is no typo. The previous owner was the "Army Corp of Engineers". Government vehicle. Very well maintained. I would like to back flush the engine block and heater core and bypass the radiator. The original radiator was completly clogged so I purchased a 3-row. So should I connect a garden hose to the top radiator hose or the bottom radiator hose? The engine will be running with the heater full blast. Would it not make more sense to flush thru the bottom radiator hose so the water pump sucks water through the block instead of fighting against the water pump?

I recently installed a 4WD 3" lift.
All new bushings.
Custom roof rack.
Kumho MT 235/75/15 tires

Thanks Guys...
 
If you still have the original rad pull the new one and resinstall the old one and refill with water, add the 7 hour flush and drive that for the time specified. That will not only clean the old system but give you a spare radiator incase the new one starts leaking. The 7 hour stuff is very good and basically breaks down the build up a bit more gradually than those 15 min shock flushes. If the new one is a GDI keep an eye on it. The 7 hour types are made both by zerez and prestone, I use the prestone because its always around and has always worked. I know swapping rads is a small PIA but I don't know if I would want that flush in there in a new rad. I've seen what it does to an old corroded one that looked like the inside of Howe caverns and after 8 hours of driving the solder looked new in there and the brass was shiny. It might not do anything to the new one buy why take a chance...Those shock flushes to me are like sandblasting and leave alot of solid material loose in the system. Every time I have used them I usually ended up replacing a water pump within a couple of months.
 
Back
Top