Water pump or hose leak.

[bootsy]

I've got the 06 xlt v6 4x4. Just replaced the radiator and thermostat as usual. Now I have coolant coming from either the water pump or one of the smaller hoses connected to the bottom of the pump. I've read some threads about the pump going but has anyone had the small hose go instead? The leak is right at the junction of the pump and the small hose. Could it be that I just need to tighten the clamp on the hose or move the clamp closer to the pump in order to seal?

Any advice would be appreciated. Thanks.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 2006-2010 section. Connect a cooling system pressure tester onto the system to see where the leak is coming from.

 

[stroker393]

Your problem is more than likely the 1" OD bypass hose between the t/stat housing and the water pump. I'm currently working on my '07 4.0 Eddie Bauer with that hose issue as it burst under load pressure. I replaced a leaking radiator at 56,000 miles and 3000 miles later this hose goes. There is a problem with the cooling systems on our 06-07 4.0 models and I'm still trying to put a finger on what actually is causing the failures. My hose when I got it off had a tiny slit on the back side near center but looking on the inside of the hose it had several separation slits that hadn't made it all the way through; a pressure burst. For some reason Ford decided to put 20psi caps on this system, not the usual 16psi ones that they have always used. Do a search about this hose issue and also radiator and you'll find lots of post. If this was a rare occurence I wouldn't think no more about it but for this many radiators to go and then this hose there isn't a part problem but a Ford cooling system problem. What part will fail next.

 

[michael loibl]

Does anyone know of a 15-16 pound cap that fits this system? I'd be willing to give it a try. I've grown rather attached to radiator number three here, being as the warantee ran out 18 months ago.

 

[stroker393]

Stant cap (#10233) is a 16 lb and used on the 94-2001 Explorers and other Fords with the 4.0 V6. In 2002-2005 Ford switched to the system with no rad cap and only coolant recovery screw-on cap. In 2006 thru 2010 for some reason they went with the 20 lb. My bypass hose wasn't aged, it burst from pressure and I looked closely in the bends of my upper and lower radiator hoses and there were hair line cracks starting so they got changed also. I've got 300 miles on my rebuilt system running the 16 lb cap and everything is fine with no difference where my needle is on the temp gauge.
Water boils at 212 degrees and when pressurised you raise the boiling point thus saving your engine. The boiling point of water will raise 3 degrees for every pound of pressure your cap is rated:
16 lb PSI = 260 degrees
18 lb PSI = 266 degrees
20 lb PSI = 272 degrees

There is no logical reason for Ford to run 20 lb PSI caps on only the 2006-2010 models; maybe this was a test for some lower emissions they were trying to acheive in which they failed badly. Still trying to get the cap rating for the 2011 models with the new 3.5 V6. From what I've seen the 4.0 is gone. My final take on all of this is the 2006 was where we all saw the big radiator numbers failing, Ford realized the error and designed a stronger radiator and had all other manufacturers do the same but if you have had more than one failure you got one of the first designs. The radiator leak bulletin didn't come out until Aug-Sept 2009 so probably some 08-09 models may hold the first design. My rad went at 56,000 on 10/2010 (I have it boxed in my attic garage) so I feel like I got the newer design models. If there is another weak link in our systems then hopefully I've saved myself some future work on replacement parts but only time will tell now. I did replace a ton of parts due to the bypass hose burst:

-lower t/stat housing ( one of the long bolts had scale/rust on it but the bolt isn't in water; slow leak starting within the housing)
-t/stat (original was stamped 106 C; if this is celsius thats 222 degrees) replaced with 195
-all orings, even new oring on temp sender
-bypass, upper, lower rad hoses
- even cleaned top of intake valley while I could get my hand in there with Permatex rust remover gel; looks brand new

 

[richardodie2]

rad cap # 10233

Just bought the stant rad cap rated for 16 psi , will give it try and see what happens, fingers crossed

 

[stroker393]

Update on my system running the 16 PSI cap; I got 61,000 miles and no problems. Explorer is running strong with no noticeable difference in vehicle operation and cooling system is doing its job. Ford; if you are reading this get with your R&D department and research this issue so you never let us down again. We all just don't buy a Ford for transporation only; we buy for the brand too. I am a loyal owner and have been since I got my first in 1976 and Ford is the only thing in my yard.