M998 leaking coolant from front of engine behind power steering

[boster58]

Hello , I have had a overheating issue for months . I finally got a new fan hub , water pump , correct thermostat, Cadillac valve , control timer and temperature control unit . Drove Humvee around for 2 days no issues temp staying between 195 - 215 not going any higher but fan not cutting on.

checked with laser temp gauge and it stated about 10 degrees cooler so I think temp is were it should be .

now the issue , drove on a 70 mile round trip and when I got home antifreeze started coming out behind power steering pump area ? Not sure if it blew a head gasket or if something could be leaking back there ? Any help appreciated

live in Daytona beach Florida

 

[Guyfang]

Boster,

Welcome to the Forum! I am going to mover this thread to the Hummer Forum. You will get much more help there, then in the Conversation Forum.

 

[Mogman]

The best I can suggest is get a pressure test kit, pressure up the system and use a mirror on a stick to look around and see where it is coming from, several possibilities.
I would say in FL it would be rare to have the fan not come on during a 70 mile jog.

 

[MarkM]

Most I can get in the summer is around 8 miles or so before the fan comes on. Could it be leaking on the water pump mounts? Since you were in there that is where I would start. Why did you change out the water pump? Good luck.

Mark

 

[Retiredwarhorses]

Go find the leak…clean it off, blow it off, install a pressure system tester, air it up to say 10psi and see where it’s coming from…could be from the thermostat housing, thermostat cross over etc…

 

[boster58]

Most I can get in the summer is around 8 miles or so before the fan comes on. Could it be leaking on the water pump mounts? Since you were in there that is where I would start. Why did you change out the water pump? Good luck.

Mark

I changed the water pump because it started overheating . The water did not appear to be moving so I changed it . While I had it apart I decided to see if I could get fan to come on as it had never worked since I had truck for last 6 years . I purchased new military thermostat, military radiator cap , Cadillac valve , fan hub and thermostat controller module . However still no water circulating . At that point I started checking all lines to see we’re water was not flowing . I found on the tank that you add coolant to there were to lines . One went to cross over tube and the other to radiator were both blocked. I decided to drill them slightly larger the original and truck started circulating water properly and temp stay in 190 range , when driving it went to 215 but no higher . Checked with laser gun and temp was actually about 5-10 degrees cooler the gauge was reading . I also but a oversized aluminum radiator and trans cooler a year earlier as the original went bad .

 

[boster58]

The best I can suggest is get a pressure test kit, pressure up the system and use a mirror on a stick to look around and see where it is coming from, several possibilities.
I would say in FL it would be rare to have the fan not come on during a 70 mile jog.

The 70 miles was 35 miles each way and stopping for lunch before returning home truck stayed steady at 210

 

[boster58]

The best I can suggest is get a pressure test kit, pressure up the system and use a mirror on a stick to look around and see where it is coming from, several possibilities.
I would say in FL it would be rare to have the fan not come on during a 70 mile jog.

 

[boster58]

Update , did the pressure test and the water is coming from a bolt in either the alternator/power steering bracket . Soon as I got 10lbs on it water started to flow

 

[Mogman]

Make sure it is not coming from above somewhere, the picture is of little use.
If it is not coming from above (water cross over etc) it sounds like the water pump or the timing cover behind the water pump is leaking.

 

[boster58]

Make sure it is not coming from above somewhere, the picture is of little use.
If it is not coming from above (water cross over etc) it sounds like the water pump or the timing cover behind the water pump is leaking.

 

[boster58]

It’s coming out of bolt hole closest to temp gauge sending unit

 

[Mogman]

The bolt holes in the front of the head do not extend into the cooling jacket, unless someone drove a bolt that was too long breaking into the cooling jacket. I am not sure that is even possible but some folks go to great lengths to screw things up, I suppose it is also possible the threads got stripped and someone drilled into the cooling jacket installing a helicoil.
Pull the bolt out and see if water pores out, if it does dry it all out, remove all oil and grease and try it with sealer on the bolt threads.

 

[Mogman]

Also do not start multiple threads on the same subject, the other post was deleted.

 

[boster58]

Also do not start multiple threads on the same subject, the other post was deleted.

Got it

 

[boster58]

The bolt holes in the front of the head do not extend into the cooling jacket, unless someone drove a bolt that was too long breaking into the cooling jacket. I am not sure that is even possible but some folks go to great lengths to screw things up, I suppose it is also possible the threads got stripped and someone drilled into the cooling jacket installing a helicoil.
Pull the bolt out and see if water pores out, if it does dry it all out, remove all oil and grease and try it with sealer on the bolt threads.

Thank you for the help . Draining coolant now I think I can get to the bolt from under truck . Here are better pictures

 

[Mogman]

I would have pulled the bolt before draining to confirm that is where the water is coming from, you could always stick it back in until you drain the system.

 

[boster58]

I would have pulled the bolt before draining to confirm that is where the water is coming from, you could always stick it back in until you drain the system.

Got to get my shower gear for that lol , alternative plan is put water back in and see if comes out .

 

[mccullek]

Got to get my shower gear for that lol , alternative plan is put water back in and see if comes out .

Before you get too far along, where on the motor is this bolt and leak? If near, like in just above, the oil filter, I had a similar issue that turned out to be a clogged drain for water, rain, fuel or whatever collects between the motor and transmission. It looked like a rusted off bolt, but it was actually part of the drain tube that was stopped up from rust and small debris over time.

I cleaned that out really well and no more water leak for me. What I thought was a coolant leak was simply a drain hole that was not draining well so when you drove it, the water blew all over the undercarriage and dripped all over my driveway, making me think I had a coolant leak.

We have since had a very heavy rain more than once, and once the roads were dry, so was my engine and driveway, so it was just rainwater that couldn't find its way out of the drain quickly enough.

 

[boster58]

Got to get my shower gear for that lol , alternative plan is put water back in and see if comes out .

Does anyone know if power steering pump will come off without taking alternator off