So I recently drove the jag 2.5 hours down to Nashville to see the Lane Motor Museum. Absolutely worth it by the way, great museum. At some point in the couple of days that followed my return I ended up with a pretty substantial coolant leak. Unfortunately it was dripping onto the belts and getting flung everywhere, making it difficult to pin down where it was coming from. I added some florescent dye and washed all the old coolant off, ran it for awhile, and then was able to find the leak. Unfortunately for me, I have no idea what it is leaking from. Instead of a hose or gasket, it's coming from a little hole in my water pump. Not an accidental hole mind you, this is like a drill hole of the sort you'd expect to find a screw inside. Unfortunately I can't get up there enough to see what this hole is and I was hoping somebody here could tell me.

Hopefully you can see in the picture what I am talking about, but it isn't an easy thing to get a picture from.

I am going to order a water pump today, but in the meantime I am tempted to fill this hole with RTV as I need the car for the drive back and forth to work. If that holds, it will buy me time while the water pump arrives.
I would feel more comfortable plugging up a hole if I knew what the hole was. I am also slightly concerned that it's a symptom of a larger problem which may not be cleared up by a new water pump.

 

It's a 'weep hole'. Very common. Also very common for the shaft seals to leak .....with coolant exiting via the weep hole

Cheers
DD

 

Thanks Doug,

The shaft seals would be replaced if I swapped out the pump, so that is reassuring. In the meantime, it sounds like if I blocked this weep hole off with RTV it probably wouldn't hurt anything in the very short term. Sounds like I will end up with coolant polluting the bearings for that shaft pretty quickly once it's no longer just running out that weep hole, so I should be getting that water pump swapped out asap. Unless anybody can think of a better quick fix for the week before I can get that water pump installed, or a good reason to fear my current plan enough to find another way to get to work.

Is that the purpose of the weep hole? To get rid of any coolant that might seep past the shaft seal before it reaches the bearings?

 

Exactly !


Cheers
DD

 

Great!
I've ordered a water pump. (Product Detail)
I found that one for ~$50 and a $3 core charge on rock auto, which beat the price on JagBits (~$199 with $20 dollar core charge) sufficiently to dispel any fears about quality. I put an A1Cardone remanufactured water pump on my MGB a couple years ago and it was fine.
In the meantime I'm going out to seal up that hole in the hopes it keeps most of the coolant in the engine until the pump arrives Thursday, I'll bet it helps for a couple of days and then starts to come out by the pulley instead, followed by the catastrophic failure of the pump. So, a good idea then. As long as I make it to work and back a couple of times without covering the parking lot in coolant.

I am always glad I posted, that hole wasn't mentioned in my service manual or the Hayne's manual, I'd have had to pull the water pump just to sort out what was wrong.

 

Also a helpful video.

 

I tried to seal off the weep hole with RTV, it didn't work. The weep hole is almost impossible to get too effectively without removing the water pump. So there will be no temporary fix, the car is parked until the new water pump arrives.
The car needs to drive me six hours north on Thursday night, and I am thinking the pump will arrive Thursday. I'll probably disassemble the thing Wednesday so that I just have to install it when it arrives. It looks to be a simple job.

 

If it were me and I needed a couple of days of travel, I'd not mess with trying to seal the weep. Although a self tapping metal screw might work. Take along a gallon of premix coolant. Top off the system before driving. Ancient tech, but it works.


Doing the preop prep is an excellent plan.


I've done well with Rockauto. No disrespect to Jagbits, though.


Carl

 

As Doug confirmed, the bleed hole is to stop coolant passing a worn-out seal from getting to the pump bearings. In the "good old days" it was commonplace to replace pump seals and bolt the pump back on, I did this myself on a Mark 2 pump way back in the 80s. Nowadays when the pump starts to leak a new one is fitted, as it is so much cheaper in mechanic's time.