3.5 water pump leak

Hello all
I have a 3.5 carb engine that sprung a leak at the water pump, seemed a simple enough job despite much trouble removing the old water pump bolts I finally got it off and was about ready to fit the new pump when I discovered another potential problem.
I was checking that I have clear flow through the block with a hose when I noticed that when I put water pressure onto the heater feed pipe (circled green) I am getting water coming out of one of the water pump bolt holes (circled Orange)

My question is has anyone else had this? and other than taking the timing cover crank pulley etc etc off (which I really don't want to be starting this time of year) is there any other way of sealing it?
Any thoughts or ideas welcome

Thanks

Might want to check your post. You're saying both holes are circled in green.
BUT if you mean the one circled in orange there are 4 very long bolts (the one in the orange circle is 5") that go through the water pump & front cover into the coolant area of the block & when fitting them you need to use a thread sealant.
They are also the ones most likely to shear when removing if corroded into the block - guess how I know. Be careful when tightening & if any look dubious replace them.

Ooops, yes your quite right, circled green is direct to/from heater and where I put water in and circled orange is the bolt hole where water comes out. I'm not sure what it looks like on the inside of the timing cover or between cover and block but guess there is another gasket surrounding the bolt and it should not be able to push water out the bolt hole. I could try sealer around the bolt ofcourse, the concern is more where else the water may get to - possibly into timing cover itself?
I did have to work a long time on all 15 bolts to get them out in one piece, still had 3 break off but I was quite pleased that the long ones into the block came out.

Ratae said:

Might want to check your post. You're saying both holes are circled in green.
BUT if you mean the one circled in orange there are 4 very long bolts (the one in the orange circle is 5") that go through the water pump & front cover into the coolant area of the block & when fitting them you need to use a thread sealant.
They are also the ones most likely to shear when removing if corroded into the block - guess how I know. Be careful when tightening & if any look dubious replace them.

Click to expand...

There is a gasket between the front cover and the block.
There is a gasket between the waterpump and the timing cover.
The long bolts pass through the waterpump, its gasket, the timing cover, its gasket & screw into open threaded holes in the front of the block where the waterways are thereby sealing the holes. Why they didn't make all holes blind is something only LR or Buick could tell you but it seems daft to me. They clamp the waterpump to the timing cover and the whole thing to the block.
The sealant on the threads is necessary to seal and prevent the coolant corroding the steel bolt threads & the aluminium block threads into a solid mass.
My LR manual specifies Loctite 572 lubricant sealer on the threads of the 4 long bolts & that's what I used when I did a cam & top end overhaul last year.
One of mine was badly corroded & the bolt sheared. I had to fit a helicoil to restore the thread. I can't remember if all 4 of the long bolt holes are open to the coolant at the block end - but if you want to check then you'll need to take your timing cover off.

ETA I've done a few waterpumps on mine over the years - incl 3 over 2 days due to a faulty batch of pumps - & never had a gasket cover/pump leakage issue after fitting or an unexplained water loss. Bear in mind there are other short bolts holding the cover to the block so I wouldn't expect the gaskets to be disturbed sufficiently to leak

This might give you an idea of what's involved with the timing cover:
http://new.lrcat.com/#!/1230/73417/74385/5981
& this a rough idea of the pump, bearing in mind several different pump shafts have been used depending on the year:
http://new.lrcat.com/#!/1230/73417/75066/6008

Thanks for the info, I had assumed all the bolts holes would be capped not open to the waterways so seems I was worrying about nothing, sealed up the threads on the long bolts with 572 and its all back together now and seems ok.

Thanks again

Having thought about it I do wonder whether they left the holes open to avoid a build up of crud which would happen in a blind hole.
Cleaning out the bottom of a long blind hole would be awkward & if you didn't then when you tighten the bolt it would compress the crud & you then risk shearing what is a relatively thin bolt before it clamps everything up.
Similar issue on Sprinter injectors, long blind hole & a thin stretch bolt to hold them in. It's possible to shear them or even worse break through into the waterway so the hole needs to be thoroughly cleaned out before putting a new bolt in esp after the black death leakage these are prone to.