Hole in water pump casing leaking coolant

Hole in water pump casing leaking coolant

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Modrich

Original Poster:

201 posts

27 months

Saturday 18th May
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So, I filled the coolant system up with water to test for leaks after replacing the coolant hoses on my Tuscan restoration and I have 2 leaks with cold water, engine not running..

1) Temperature sensor on the block below the fuel rail, the sensor on the right. I had removed this sensor previously and replaced the copper washer, it was also gunked up with silicone obviously to fix a previous leak. I cleaned-up the faces and hoped that a fresh copper washer would do the trick but looks like I will need to try again, either with softer aluminium washer or washer and silicone. Anyone had experience with this? There is an allulinium union into the block, then the sensor screws into the union/adapter.

2) There is, what looks like an intentional hole in the water pump casing behind/at the back of, the steel coolant bend, that is leaking water/old coolant, the more I poke, the more comes out, like it was maybe blocked with silicone/gunk. It's approx. 4mm in diameter and could be threaded, maybe for a grub screw? I've tried to gently screw an M4 screw in but it won't go. Tried poking various sizes of allen keys in there to see if there's a grub screw in there but nothing, any ideas? Should this be plugged with a grub screw or dowel?

Any help would be much appreciated.

guards red

674 posts

207 months

Saturday 18th May
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That hole is usually found in most water pumps and lets ine know that the water pump seal has failed. The water is getting past the seal and is then vented through that hole.

You will need a new water pump.

Modrich

Original Poster:

201 posts

27 months

Saturday 18th May
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Aaaaaargh! Just as I thought I was getting close to getting the Tuscan on the road...

Thanks Guards Red, the more I thought about it, the more it seemed like it was a tell-tale hole for this purpose...

So it's valve cover off, balance wheel, A/C wheel and compressor off then front cover off. Looks doable with the engine insitue, am I right?



Edited by Modrich on Saturday 18th May 14:23

Modrich

Original Poster:

201 posts

27 months

Saturday 18th May
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I can't seem to find any guides on doing the water pump, just a few engine builds.

I notice Sagi Badger has experience with this, any tips SB? first issue is getting teh balance wheel off...

Any help much appreciated. I will of course write-up a highly detailed How To Guide in my build thread...

Are there any other service items worth changing whilst doing this job like change guides, oil pump etc...?

Modrich

Original Poster:

201 posts

27 months

Saturday 18th May
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Found Peter Sleemans Head refurb guide that covers removing the harmonic balance wheel and front cover...

https://www.tvr-car-club.co.uk/uploads/9/5/1/5/951...

I'll need to get a couple of puller tools.

Any tips on water pump seals and bearings would be appreciated.
AC
Motaclan do a Water pump refurbish kit (TVR KIT 14 RF) for £60. I'll wait until I've got everything removed before ordering parts.

Sagi Badger

610 posts

200 months

Saturday 18th May
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Right, yes water pump leak/failure as others stated but as mad as it sounds it may be worth a start/warm up and see if it stops. The seal most likely to weep is a mechanical seal, carbon and ceramic disc spring loaded and my experience with these is the sleeve can seize on the shaft, likely if the coolant system has not been maintained and filled with scabby old tap water, so a warm up may, may, force this to release and seal, nothing lost if it doesn’t. There are also seals, bearings and a procedure for reassembly etc and yes I have experience and yes it is a pig as the body is fragile.
I have made water pump delete parts for two of my SP6s, two O ring grooves and bolt holes in the correct place to allow complete removal and use of an electric pump as I hate these things, needs chain modifications. The OE water pump tensions one of the chains with an eccentric pinion, you rotate the whole body to tension the chain.
If you want to rebuild it search my posts, it was a while ago, funny that a week ago the shelf with water pump parts was searched for something else. Getting to it in situ is, is….., possible but with patience.
PM me if you need help, I don’t always look on here.
J

Modrich

Original Poster:

201 posts

27 months

Saturday 18th May
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Thanks for your detailed reply SB.

I have been thinking, would it hurt to drive the car with this leak to test the engine for any other issues and also see if the leak cures itself? Will this water leak get into the oil?

I did note before stripping the coolant system that a white/pink crust was around all the coolant pipe connections and the car had lived all of it's life in Essex and London (hard water areas?) so I'm thinking the crust was limescale so could well have crusted-up this mechanical seal you are talking about so it's worth a try to free it off with fresh soft water first...

Sagi Badger

610 posts

200 months

Sunday 19th May
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Yes I would try it. Sadly there is no way of getting to the pump without removing the timing case. Is there a risk of water contaminating oil, doubt it. The hole is there to relieve pressure so that the water does not find its way into the timing case.

Word of caution, these can air lock of you rush the filing, and there isn’t much head above the cylinder head and any water loss will drop the level around the valve seats. If you look into a cylinder head waterways from the head face there will most likely be evidence of cavitation, so if you drive with a leak don’t push your luck. I have converted my Tuscan to the 350/Sag set up with a remote expansion, it sits on the OS inner wing tucked up as high as possible, that is how concerned about the water level I am.

Lastly, you mentioned pullers, you will need a stout one and luck. Frankly I wouldn’t attempt it in situ, I would have the engine out. I know Pete S, he has more patience than me… so if you are lacking tools and your heart isn’t in this then don’t attempt in situ.

Modrich

Original Poster:

201 posts

27 months

Monday 20th May
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Interesting about the Sag remote expansion I will lokk into that, an pics of your installation SB?

If the leak persists after running the engine for a while then I'll tackle the job myself. I don't have a puller but there's a few on ebay that might work, Peter recommends a heavy duty one then a smaller one for the final stages.
text
This looks promising with 15mm thick plate: https://www.ebay.co.uk/itm/404957554113?itmmeta=01...

and this for final stages: https://www.ebay.co.uk/itm/185731059702?_trkparms=...

To add insult to injury, I will have to remove all the tanks and likely even the steering rack spacers so the bolt can clear the rack when pulled out...



Edited by Modrich on Monday 20th May 10:26

Modrich

Original Poster:

201 posts

27 months

Tuesday 21st May
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Well, in true TVR fashion, and as you suggested SB, the leak has cured itself. I had drained most of the water off after I found the leak, then yesterday refilled it to check again as SB suggested, not a drop leaked from the tell-tale hole, cold. Today I ran the engine for 10mins to get the water hot and just a tiny drop of old coolant came out then it was dry. I still have a leak from the block water temp sensor, I resealed the actual sensor which is now ok but there is still a leak from the union into the block which I haven't removed so this will need stripped and cleaned.

One think to note, I blew the 100amp fuse from the alternator/starter to the battery yesterday trying to started engine. I have fitted a new high torque starter so maybe this needs a higher rated fuse?


Stunned Monkey

354 posts

216 months

Monday 8th July
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That hole is between two O-rings on the pump body. The leak tells you the 1st Oring has failed. You don't need a new pump, you do need a new O-ring or two. It's quite easy but will require removal of the timing cover.