1998 Ford Taurus Rupturing Overflow Tanks

GROOVEJUNKIE

MEMBER
1998 FORD TAURUS
6 CYL
FWD
AUTOMATIC
170,000 MILES

I've got a 98 taurus, standard 3.0 six, that has ruptured three new coolant overflow tanks in the span of 18 months. These were from two different suppliers, so I am unwilling to believe "I just got three bad ones".

There has to be something that is causing this consistent failure other than a bottle design flaw. It shocks the heck out of me that a thick-walled plastic surge/overflow tank with a 16PSI release cap would regularly rip open lengthwise from heat and pressure.

One item that I've recently replaced as a possible cause of excessive system pressure was the thermostat, which seemed to never fully open when tested. I'm now running a 185-degree failsafe unit. In addtion, six months after a complete coolant flush, there was serious corrosion residue in the bottom of the split tank and in the remaining post-rupture coolant (last night).

However, there was plenty of flow to the overflow tank/bottle through the top return tube when I checked the system unpressurized (cap off), so no serious system blockage that I know of.

I've seen the bottle rupture and block corrosion in coolant talked about in TSB-1116/NHSTA-622646, but I can't find any mention of a fix, solution, or recommended action to stem the listed issues.

Any idea of what could be causing the consistent pressure failures of the tanks? Any clues as to why the tanks fail before the caps release? Any hints on stemming the rampant system corrosion present even with frequent coolant changes?

Thanks.

3 Replies

DAVE H

MECHANIC
13,383 POSTS

The TSB 01-11-6. Explains the reason is "bank to bank coolant flow imbalance" in other words the pump is not upto the task? You need to replace pump, add bypass kit if not already installed and totally flush the system. Have you checked with dealer if this can be done with little or no cost to yourself?

COOLING SYSTEM - 3.0L VULCAN ENGINE ONLY - VARIOUS COOLANT RELATED SYMPTOMS - CONTAMINATED OR DISCOLORED COOLANT
TECHNICAL SERVICE BULLETIN
Reference Number(s): 01-11-6, Date of Issue: June 11, 2001
FORD:1996-1999 Taurus
MERCURY:1996-1999 Sable
Superceded Bulletin(s): 97-24-16, Date of Issue: November 24, 1997, 99-6-8, Date of Issue: April 5, 1999
Related Ref Number(s): 01-11-6, 97-16-5, 97-24-16, 98-5-3, 99-6-8
ARTICLE BEGINNING
ISSUE
NOTE:THIS ARTICLE DOES NOT APPLY TO GULF COAST COUNTRY (GCC) VEHICLES EQUIPPED WITH ENGINE OIL COOLER. A SEPARATE TSB WILL BE RELEASED SOON FOR THESE APPLICATION.

Some vehicles may exhibit cooling system conditions such as:
Contaminated/corroded coolant
Leaking/Cracked/Discolored Coolant Overflow bottles
Vibration or thumping from engine
Leaking heater core
Coolant overflow
High temperature gauge readings
Fluctuating temperature gauge
Stuck Thermostat
Heater hose leaks
Leaking head gasket
Lack of heat
This may be caused by:
Coolant level that falls below the cold fill range due to un-serviced leaks, improper fill after service and lack of coolant level maintenance that may lead to cooling system overheat damage.
NOTE:IT IS RECOMMENDED THAT THE COOLANT CAN BE SAFELY FILLED TO THE TOP OF THE CLEAR PORTION OF THE BOTTLE (WHEN THE ENGINE IS COLD) TO PROVIDE EXTRA RESERVE COOLANT. (Fig. 11 ).

Bank to bank coolant flow imbalance on some 1996-98 model year vehicles.
ACTION
Perform the following repairs based on model year application. Check repair history to determine if prior repairs were performed.
1996-97 3.0L Vulcan - If bypass kit was previously installed, then install new water pump (1F1Z-8501-AA) and perform the entire SEDIMENT/CHEMICAL FLUSH and fill procedure. If bypass kit was NOT previously installed, Install coolant bypass kit (F7DZ-8522-AB) OR (METHANOL VEHICLES F8DZ-8522-CC), new water pump (1F1Z-8501-AA) and perform the entire SEDIMENT/CHEMICAL FLUSH and fill procedures.
1998 3.0L Vulcan - Install Coolant bypass kit (F8DZ-8522-BA) on vehicles built 9/1/1997 - 1/23/1998. Install water pump (1F1Z-8501-AA) on all 1998 models regardless of build date. Perform the entire SEDIMENT/CHEMICAL FLUSH if bypass kit was NOT previously installed. If bypass was previously installed or vehicle is outside the coolant bypass build range the CHEMICAL FLUSH and Fill procedure may be sufficient.
1999 3.0L Vulcan - Perform FLUSH AND FILL PROCEDURE AND CHEMICAL FLUSH ONLY.
SERVICE PROCEDURE
Perform normal diagnostics as outlined in the Cooling System Symptom charts located in the appropriate model year Workshop Manual. Service as required.
If not previously installed, install appropriate Coolant By-Pass Kit. Refer to the Instruction sheet included in the kit for details.
Install water pump on 1996-98 models only. Refer to Workshop manual, Section 03-01A for replacement details.
Perform the following flush and fill procedures if coolant is discolored.
FLUSH AND FILL PROCEDURE RECOMMENDED TOOLS
The tools shown in Fig. 1 are referenced throughout the technical Instruction to facilitate the flush procedures. Tools should be obtained locally.
FLUSH AND FILL PROCEDURE
NOTE:POSITION THE VEHICLE ON A HOIST WHERE A GARDEN HOSE CAN BE USED AND COOLANT CAN BE DISCARDED.

WARNING:COOLANT MAY BE HOT. REMOVE COOLANT PRESSURE RELIEF CAP.

1) Raise vehicle on hoist.
2) Remove splash shield.
3) Remove Radiator draincock and completely drain and discard coolant.
4) Lower vehicle.
5) Loosen alternator brace retaining nuts and position brace away from heater return hose (Fig. 2 ).
6) Turn Heater and Blower Switches to off.
7) Disconnect heater return hose from water pump and discard clamp.
8 FOR 96, 97 AND SOME 98 MODEL YEAR VEHICLES PROCEED WITH THE SEDIMENT AND CHEMICAL FLUSH PROCEDURES. FOR 99 MODEL YEAR, COMPETE THE CHEMICAL FLUSH PROCEDURE ONLY.
SEDIMENT FLUSH PROCEDURE
9) Disconnect upper radiator hose from thermostat housing and discard clamp.
10) Using clamping pliers, clamp off coolant by-pass hose at center of hose (Fig. 3 ).
11) Raise and support vehicle.
12) Remove engine block core plug located next to the oil filter. On the opposite side of the engine block, there are two core plugs; remove the engine block core plug closest to the water pump.
13) Remove lower radiator support bracket that covers lower radiator hose.
14) Remove lower radiator hose from radiator and discard clamp.
15) Clean core plug bores in cylinder block with sand paper drum (Fine 150-grit 1.5" dia.). Ensure all Loctite and rust is removed from core plug bore.
16) Lower vehicle.
17) Connect garden hose to heater return hose using adapter (Fig. 4 ).
18 Turn garden hose on full pressure.
19) Flush engine/heater core for ten (10) minutes. Water will drain out of core plug holes.
20) Disconnect garden hose from heater return hose.
21) Insert garden hose into upper radiator hose (Fig. 5 ).
22) Flush radiator for two (2) minutes. Water will drain out of lower radiator hose connection and draincock.
23) Remove garden hose from upper radiator hose.
24) Insert garden hose into coolant recovery bottle (Fig. 6 ).
25) Flush coolant recovery bottle for four (4) minutes. Water will drain out of lower radiator hose.
26) Remove garden hose from coolant recovery bottle. Let cooling system completely drain before proceeding to next step.
27) Remove clamping pliers from coolant by-pass hose.
28 Install new screw clamp on upper radiator hose. Connect upper radiator hose to thermostat housing and tighten clamp.
29) Raise and support vehicle.
30) Lubricate O-rings of new engine core plugs (-6C057-) with silicone dielectric grease (WA-10).
31) Install left and right bank front engine core plugs. Index dimples on the plugs to 12 o'clock position. (Fig. 7 ).
NOTE:DO NOT OVER TORQUE.

32) Tighten core plug retaining nuts to 3.2 N.M (28 in-lb). See Fig. 7. Use 1/4" drive, 8mm flex socket with a long extension is acceptable. Make sure plugs do not rotate when tightening retaining nut.
33) Install new screw clamp on lower radiator hose. Connect lower radiator hose to radiator and tighten clamp.
34) Install lower radiator support bracket. PROCEED TO STEP 36 and continue.
CHEMICAL FLUSH PROCEDURE
WARNING:WEAR RUBBER GLOVES DURING THIS STEP. CHEMICAL CLEANER MAY CAUSE SKIN IRRITATION.

35) Partially raise vehicle.
36) Install radiator draincock.
37) Lower vehicle.
38 DO NOT add chemical cleaner to the coolant recovery bottle. Using a funnel, slowly add one (1) bottle of chemical cleaner (F8AZ-19A503-AA) into the HEATER RETURN HOSE (Fig. 8 ).
NOTE:THE RECOMMENDED CHEMICAL CLEANER MUST BE USED.

39) Connect and clamp the heater return hose to the water pump fitting.
40) Slowly fill cooling system with water. Squeeze upper radiator hose to purge air from system as water is added. Coolant level must be filled to the top of the clear portion of the coolant recovery bottle to completely clean the coolant bottle.
41) Start engine and raise RPM to 2000 RPM for 2 minutes. Do not exceed 2500 RPM.
42) Check cooling system for leaks.
43) Recheck coolant level. Add water, if necessary to bring level up to the top of the clear portion of the bottle.
44) Install coolant bottle pressure relief cap.
45) Run engine at idle until upper radiator hose is hot (when thermostat opens) approximately 12 minutes.
46) Turn engine off and let chemical solution soak for a minimum of thirty (30) minutes, while engine cools.
WARNING:COOLANT MAY BE HOT. REMOVE COOLANT PRESSURE RELIEF CAP.

47) Partially raise vehicle.
WARNING:WARNING WEAR RUBBER GLOVES FOR THIS STEP. CHEMICAL CLEANER MAY CAUSE SKIN IRRITATION.

48 Remove radiator draincock.
49) Completely drain chemical solution and discard.
50) Lower vehicle.
51) Disconnect heater return hose from water pump fitting (Fig. 9 ).
52) Install a 3/4" I.D. Rubber cap on the water pump heater hose fitting (Fig. 9 ).
53) Disconnect and plug radiator overflow hose from coolant recovery bottle. Discard clamp (Fig. 10 ).
54) Attach a 4 foot section of 3/8" vinyl hose to overflow fitting on the coolant recovery bottle. Let vinyl hose hang over fender (Fig. 10 ).
55) Install coolant pressure relief cap.
56) Connect garden hose (water supply) to heater return hose using 3/4" adaptor.
57) Turn garden hose on full pressure.
58 With engine off, flush engine for at least five minutes and until water is clear. Water will drain out of radiator draincock and the 4 foot vinyl hose.
59) Turn garden hose off and remove pressure relief cap from bottle.
60) Disconnect garden hose from heater hose. Let cooling system completely drain before proceeding.
61) Raise vehicle.
62) Install and tighten draincock.
63) Install splash shield.
64) Lower vehicle.
65) Remove rubber cap from the water pump.
66) Install new screw clamp on heater return hose and reconnect to water pump. Tighten clamp.
67) Reattach and secure alternator brace.
68 Remove 3/8" vinyl hose.
69) Unplug radiator overflow hose and install new screw clamp. Reconnect radiator overflow hose to coolant recovery bottle and tighten clamp.
70) Add one (1) bottle (16 oz) of heavy duty cooling system additive (FW-16) to coolant recovery bottle.
71) Add six (6) quarts of new coolant to coolant recovery bottle. Fill remainder of cooling system with water to top of clear lower portion of coolant recovery bottle.
72) Start engine and top off with water to top of clear lower portion of coolant recovery bottle (Fig. 11 ).
NOTE:THE NEXT STEP MUST BE DONE BEFORE THERMOSTAT OPENS.

73) Raise engine RPM to 3000 RPM for 30 seconds and check for foaming inside the coolant recovery bottle. If foaming is present the coolant by-pass restrictor has not been installed. Turn off engine and install the coolant by-pass restrictor (F7PE-8N030-AA) contained in 1996-1997 bypass kit (F7DZ-8522-AB). Refer to coolant by-pass restrictor installation procedure in the bypass kit instructions.
74) Install coolant pressure relief cap.
75) Select maximum heater temperature and blower motor speed settings. Position control to discharge air from the instrument panel vents.
76) When vehicle reaches normal operating temperature, verify hot air from panel vents and a hot upper radiator hose.
77) CAUTION: If air discharge remains cool and engine coolant temperature gauge does not move, engine coolant level is low and must be filled. Stop engine, allow to cool and fill cooling system to top of clear lower portion of coolant recovery bottle.
78 Start engine and allow it to idle until normal operating temperature is reached. Hot air should discharge from panel vents. The engine coolant temperature gauge should maintain a stabilized reading within the NORMAL range and upper radiator hose should feel hot to touch.
79) Shut engine off and allow engine to COMPLETELY COOL.
80) Check engine for coolant leaks.
81) IF NECESSARY, ADD COOLANT UNTIL LEVEL IS AT THE TOP OF THE CLEAR PORTION OF THE COOLANT BOTTLE (Fig. 11 ).
82) INFORM CUSTOMER THE IMPORTANCE OF MAINTAINING COOLANT LEVEL. IT'S RECOMMENDED THAT COOLANT CAN BE SAFELY FILLED TO THE TOP OF THE CLEAR PORTION OF THE COOLANT BOTTLE WHEN THE ENGINE IS COLD. THIS PROVIDES EXTRA RESERVE COOLANT.
PARTS INFORMATION
PARTS INFORMATION
Part NumberPart Name
F8AZ-19A503-AAChemical Cleaner
FW-16Coolant Conditioner
VC-4AEngine Coolant
F7DZ-8522-ABCoolant By-Pass Kit - 96-97 Taurus/Sable
F8DZ-8522-BACoolant By-Pass Kit - 98 Taurus/Sable
F8DZ-8522-CCCoolant By-Pass Kit - 96-97 Methanol Taurus/Sable
1F1Z-S501-AAWater Pump - 96-98 Taurus/Sable
F8DZ-6C057-AACore Plug

WARRANTY INFORMATION
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage.
WARRANTY INFORMATION
OperationDescriptionTime
011106AReplace Water Pump (Includes Time To Perform Sediment And Chemical Flush And Fill Procedures) 1996-1998 3.0L MFI, 3.0L FFV4.1 Hrs.
011106BReplace Water Pump And Install By-Pass Kit (Includes Time To Perform Sediment And Chemical Flush And Fill Procedures) 1996-1998 3.0L MFI, 3.0L FFV4.6 Hrs.
011106CPerform Chemical Flush And Fill Procedures 1998-1999 3.0L MFI, 3.0L FFV1.6 Hrs.

DEALER CODING
Basic Part No. Condition Code
8A08049