Coolant Tube Problem

[Vanguard]

I'm having a problem with the large coolant tube where it enters the water pump. It seems to be the source of my original coolant leak. I suspect my original water pump is still good.

I replaced the water pump once took it for a test drive and found it leaking the next morning. As I posted in another thread I figured the RTV had cured and the pump wouldn't seat. Well I got new gaskets, new o-rings and removed the !#$!#$! RTV. Reinstalled the pump, refilled the coolant and test drove it. No leaks in the morning. Went to work. Puddle under the car after work. Plenty of coolant left, drove home. Coolant level still fine. Checked every couple of hours after getting home. No leaks.

Got up this morning to another puddle after the motor cooled. Did I miss a step or is there some trick to getting the tube to seat? After changing the pump twice I'm getting sick of working on it and my wife is fed up with me. It's Halloween tonight so this is going to have to wait until tomorrow again. #$!#@$@!.

Any help would be appreciated.

[TC535i]

I've heard the coolant tubes on the V8's can pull out if you're not careful, but that was on removal of stuff up front, so they'd pull out in the back.

Are the puddles just on the ground, or can you locate where they're leaking from?

[Jon K]

Throw some UV dye in the coolant - I know it sounds crazy but I have a link to the dye I mix in with glycol coolant for my PC. Mix it in, drive it, let it leak, get a black light, and inspect!

[Vanguard]

It's leaking up front after the motor cools. I was careful not to pull them out of the back after reading past threads on what it would take to fix it.

[TC535i]

It's leaking up front after the motor cools. I was careful not to pull them out of the back after reading past threads on what it would take to fix it.
yeah, that's what I'm talking about... that's the only coolant tube issue I've heard of, if it's leaking up front I'm not sure.

I'll probably get flamed or sometihng, but have you tried Bar's Leaks? Worked on my 318 tstat housing that wouldn't seat for some reason or another, tried reseating/resealing about 6 or 7 times and I'd still get a trickle down the front of the block. Hit it with a bottle of bar's leaks, and tracked it several times since... no coolant loss.

[Vanguard]

I'm leary of the bar's leak. I think the coolant leak began at same spot as well. I've ordered new cooling tubes, another set of o-rings and gaskets. I think I'm going to throw on the UROs pump as well this time.

Is it supposed to be very hard to seat the tubes, when you the pump is installed? Per the Bentley I used some petroleum jelly on the tube ends and o-rings to help them seat. They went on very easily.

[TC535i]

I'm leary of the bar's leak. I think the coolant leak began at same spot as well. I've ordered new cooling tubes, another set of o-rings and gaskets. I think I'm going to throw on the UROs pump as well this time.

Is it supposed to be very hard to seat the tubes, when you the pump is installed? Per the Bentley I used some petroleum jelly on the tube ends and o-rings to help them seat. They went on very easily.
yea, no problem with my 540... just rubbed some of the fresh coolant on the rings and it slid right on.

[Ferret]

yea, no problem with my 540... just rubbed some of the fresh coolant on the rings and it slid right on.

I've just used 'Radweld' which is pretty much the same stuff as 'Bars Leaks' on my 540i - it's sealed up the leaking heater matrix a treat! I was thinking I was going to have to spend hours pulling the dash out and it stopped the bugger leaking in 5 mintues. Good stuff!

[leicesterboy15]

How does plugging this stuff work? My car seems to dump coolant when the engine is cooled down as well. I had a leaky rad and water pump and I replaced both but the leak is still there although I'm not sure if something was installed incorrectly or I had this leak before anyway. My coolant sensor fires about once a week but mostly when I go to start the car after standing for a few hours and not when I turn the car off. Mine collects in the plastic engine under tray like its dripping off the front of the sump. I've tried locating the leak but I can't find it so I suspect this might be my problem as well as I take it the joins you are all on about are under the intake so not immediately visible?

Jon K - any chance of that link?

[leicesterboy15]

Just fond a pic - is it the two pipes that lead back from the pump?

http://i37.photobucket.com/albums/e97/brighterbuys/My%20Stuff/IMG_1932.jpg

I guess the only way to do this properly is to take that damn intake off again?

[Vanguard]

Yep. Those are the pipes. I read another thread where someone had pulled the radiator and had enough room to slide the pipes in without messing with the radiator. I'm going to try it this weekend. I've got new pipes, new orings, a new pump gasket and another new pump.

I'm hoping installing the o-rings in the accumulator can be done without removing the intake. That looks like the biggest issue to me.