Found a crack in my radiator. 99 ranger 4.0 Used some Stop Leak but didn't help.

Ordered new radiator which will be here Monday. Took the old rad out today. My question: Is there a problem with me sticking a garden hose in the disconnected hoses and running clean water in there before hooking up the new radiator? Just to flush some of the old stuff out?

 

That's the time honored method. I did it to my Ranger multiple times (very dirty system), my father did it to his 01 and also did it to his Taurus.

The only thing you have to be careful with is to not absolutely blast the heater core with full pressure, otherwise you'll destroy it. Other than that, hose away.

I strongly suggest removing the thermostat then replacing with a new one once you're done, plus a new radiator cap if the new radiator doesn't already come with one. Of course, don't buy the cheapest one but also not the most expensive. I find the dirt cheap parts (and anything with duralast on it) simply don't last and you wind up doing the same repair all over again. I also suggest getting one of those $5 flush-n-fill kits found in several places. I've seen them in blue and yellow with different brands but, they're the same thing. Reason being will become clear in just a moment.

In the kit there should be three or four different size T fittings and a cap. Remove the heater control valve, toss it in the bin and stop up the vacuum hose. I used a golf T and a ziptie to keep it out the way and hidden. With that out of the way, find the T fitting that fits nicely into the hoses where the heater valve was and install it.

I did this to mine as a permanent install for a couple reasons. One, it makes draining and refilling the system much easier. The heater core is at the top of the system, and it can make getting the air out a real PITA. After getting the radiator full, the cap can be removed and the system can be topped off from here to help get more fresh coolant where it needs to be. It also means the system will initially 'consume' less coolant as the air is removed.

Second reason is longevity. If you rarely use your heater, the valve stays closed and that coolant just sits there stagnant. The T valve permits full flow 24/7. If you're wondering, no it won't compromise the functionality of your A/C, thanks to the blend door, which completely blocks the heater core when turned to full 'cold' on the climate control panel.

Third reason is to help you flush the gunk and other junk out of there. The kit comes with an adapter that allows you to hook the hose straight to this T valve and wash the crud from the top of the engine out through the lower radiator hose.

....should go without saying that you want to leave the new radiator disconnected until it's flushed. No reason to get that crap all in your virgin radiator. Sounds obvious but, well I'd be lying if the obvious didn't fly over my head before.

Also, as a tip. If you find the system is still pretty grody after you're done, fill the cooling system with water (preferably distilled, but hose water will also do for a short time), paying mind to the dropping temps. With just water in the system, dump in a flush chemical product, such as one by prestone and drive it for about a week. That will aid to remove more junk as well as the heat from the engine itself. Hot water cleans better than cold water, after all. I do suppose one could also flush the engine with water straight from the water heater too....

Good luck!

 

There is some good information posted by The Arcticwolf1911

I will add a TSB that effects cooling systems in 1997 - 2007 Rangers that shows common causes of repetitive heater core leaks, that may become a issue if the system is not serviced properly.

I would re consider just removing the heater control valve permanently without adding in a inline heater hose restrictor due to information found in this TSB.

It would be a shame that the wrong kind of preventive maintenance could shorten the life span of hard to change part like the heater core.

This TSB is just something I came across and felt I should share yet I do not know how much flow is too much flow and when and if it will ever become a problem.

Take it for what it is a TSB which is a solution or workaround for a poorly designed system that can effect poorly maintained vehicles more often than maintained vehicles.

The TSB is also helpful by giving you procedures that can be used to make sure the cooling system is properly flushed and give you a way to measure it using a DVOM.





TSB 06-21-19
10/30/06
HEATER CORE LEAKAGE AND ELECTROLYSIS (INFORMATION ONLY)
FORD:
1997-2002 Contour
1997-2007 Crown Victoria, Mustang, Taurus
2000-2007 Focus
2002-2005 Thunderbird
2005-2007 Five Hundred, Freestyle
2006-2007 Fusion
1997-1999 F-250 Light Duty
1997-2003 Windstar
1997-2007 E-Series, Expedition, Explorer,
F-150, F-53 Motorhome Chassis,
F-Super Duty, Ranger
2000-2005 Excursion
2001-2003 Explorer Sport
2001-2007 Escape, Explorer Sport Trac
2004 F-150 Heritage
2004-2007 Freestar
2005-2007 Escape Hybrid
1999-2007 F-650, F-750
LINCOLN:
1997-2002 Continental
1997-2007 Town Car
2000-2006 Lincoln LS
2006 Zephyr
2007 MKZ
1998-2007 Navigator
2002-2003 Blackwood
2003-2005 Aviator
2006-2007 Mark LT
MERCURY:
1997-2002 Cougar, Mystique
1997-2005 Sable
1997-2007 Grand Marquis
2005-2007 Montego
2006-2007 Milan
1997-2002 Villager
1997-2007 Mountaineer
2005-2007 Mariner
2006-2007 Mariner Hybrid
This article supersedes TSB 01-15-6 to update the vehicle model years and Service Procedure.
ISSUE
The majority of repeat heater core leaks are due to high flow rate or use of poor quality coolant. However, electrolysis should also be checked, especially when repeat repairs have occurred.
ACTION
If the heater core is leaking, review the location of the leakage and check the condition of the coolant.
SERVICE PROCEDURE
1. Review the location of the leakage and check the condition of the coolant:
a. If leaks are found on the inlet (or outlet) tubes entering / exiting the heater core, it is most likely due to due to high flow rate - replace the heater core and install a restrictor in the heater hose closest to the engine block, reference Workshop Manual, Section 412.
b. If leaks are found in the body of the heater core itself, and does not appear to be the result of physical damage like contact or puncture, check the coolant for possible electrolysis.
Testing For Electrolysis
Check for voltage in the cooling system by touching the negative contact of a voltmeter to the battery ground or a known good ground and suspend the positive lead in the coolant, making sure it is in contact with the coolant but not touching any metal part of the radiator or cooling system. Both AC and DC voltages must be checked. Vehicles normally have DC voltages; however, a faulty engine block heater or faulty diode in the alternator can produce AC voltages. It is understood that coolant is lost due to heater core failure but try to obtain a voltage reading on the old coolant in the engine block before addition to or replacement of. To keep more coolant from exiting the heater core clamp off heater core lines and measure coolant in the engine block. Try not to dilute the original coolant with new coolant during testing if possible.
1. Determine whether coolant condition is acceptable.
a. Remove both cables from the battery and ensure they do not contact each other or the vehicle.
b. Touch negative lead of voltmeter to engine ground and positive lead in the coolant.
NOTE POSITIVE TEST PROBE IS IN THE COOLANT FOR TESTING.
c. Check the voltage in the cooling system. If less than or equal to 0.4 volts (V) OK, reconnect battery cables and proceed to Step 2.
d. If greater than 0.4 V, flush cooling system thoroughly.
e. Recheck voltage less than or equal to 0.4 V.
f. Reconnect battery cables.
g. Refill the system with appropriate Motorcraft® engine coolant.
2. Check for loose or missing grounds at static conditions.
a. Turn off all accessories. Turn ignition on but do not start engine.
b. Test with ground probe to battery ground, engine ground, and vehicle ground sequentially.
c. Voltage less than or equal to 0.4 V on all grounds OK.
d. Any one greater than 0.4 V, check and clean ground cable connections.
e. Check accessories without using the on off switch on the vehicle instrument panel, use a jumper wire to ground.
f. Plug in engine block heater, if equipped, and test.
g. Recheck voltage less than or equal to 0.4 V.
h. Unplug engine block heater, if equipped.
3. Check for loose, missing, or inadequate grounds.
a. Test with ground probe to battery ground, engine ground, and vehicle ground sequentially.
b. Crank engine but do not start.
c. Monitor voltage while cranking. less than or equal to 0.4 V OK
d. If greater than 0.4 V, ground or repair starter.
e. Start engine and run at about 2000 rpm.
f. Turn on all accessories including those customer only uses occasionally such as CB radio, cell phone, etc.
g. Test with ground probe to battery ground, engine ground, and vehicle ground sequentially.
h. Voltage less than or equal to 0.4 V OK
i. If greater than 0.4 V, turn off one item at a time until V drops to less than or equal to 0.4 V. Repair ground to the accessory just identified.
j. Recheck voltage less than or equal to 0.4 V
k. Turn the DVOM to AC volts.
l. Check for ANY AC voltage greater than 0.4.
m. If any AC voltage is present then try turning off each accessory one at a time including blower motor and any fan motors.
n. If AC voltage is still present then shut engine off and remove B+ from the alternator and tape it up then retest.
o. If voltage drop is gradual to less than or equal to 0.4 V, the ground straps may simply be overloaded by added accessories. Test by using heavy gauge jumper to ground. If indicated, install heavier gauge ground strap(s) and recheck.
NOTE If vehicle is equipped with electric cooling fans, be sure they cycle during this testing and monitor voltage when they are on and when off.
CAUTION DO NOT GROUND HEATER CORE. IF THE HEATER CORE IS GROUNDED, YOU HAVE PROVIDED THE ELECTROLOSIS A PATH THROUGH THE HEATER CORE. THIS WOULD CAUSE THE HEATER CORE TO BECOME AN ANODE OR RECEIVER AND IT WOULD PROMOTE THE ELECTROLOSIS, OR ANY STRAY VOLTAGE TO USE THE COOLANT AS THE GROUND PATH.
4. Refill the engine cooling system, reference Workshop Manual, Section 303-03.
NOTE IF THE HEAT OUTPUT IS INSUFFICIENT, OR THE ENGINE DOES NOT REACH NORMAL OPERATING TEMPERATURES, VERIFY PROPER THERMOSTAT OPERATION AND REPEAT PROCEDURE IF REQUIRED.

 

I have a 1998 ford ranger 3.0 V6 and I am changing the antifreeze. I have drained and filled it with water only 4 times and on the 5th time put some flush in it and it still comes out looking brown like coke. How many times do I need to do this to get it clear.

 

Are you actually running the engine with the heater on between flushing the water?

 

Doesn't matter, heater is always 'live' - but heater could be the source, take the pipes off and flush that through separately.

 

Yes heater is on high all 5 times and now I am running #6. Never had this happen I guess I will pull the heater hoses and flush core. Good lesson to learn don't do this when the low tonight is 26.