Cooling System.

[Floaty Me Boaty]

Hi All,

Would anyone have any information as the best way to fault find a leak on my cooling system on the J3.

Is it simply a case of re-filling her and seeing what occurs?

I know it is a gravity fed system pushed around by the pump, but i just received a phone call from the Marina that the water has drained out and sitting in the bilge.

All was good a couple of weeks ago, so just enquiring if there is a 'Weak' spot i should go to first.

Did wonder that a drain cock had been knocked open, but all looks good in the pictures they sent me.

I am going up on Thursday so would be great to have some idea where to go to first.

As always, appreciate your time in replying and giving guidance.

[MtB]

Assuming a skin tank cooling system, almost certainly a flexible hose failure. 

 

Do you have antifreeze in the coolant? If it froze it probably popped a hose off and emptied on thawing. 

 

Antifreeze is more important that might first appear as it contains corrosion inhibitor too. 

 

 

[Floaty Me Boaty]

Hi,

Thank for getting back to me.

I tested the antifreeze, prior to the onset of winter, and glad to say it didn't freeze up, in our freezer.

Everything is crossed that it is a hose, but maybe i am over thinking what it could be.

I will take another bottle up with me in readiness.

I was just trying to picture the system and if i recall, it didn't look that complicated.

Doesn't help that i am only going on pictures.

[MtB]

5 minutes ago, Floaty Me Boaty said:

Hi,

Thank for getting back to me.

I tested the antifreeze, prior to the onset of winter, and glad to say it didn't freeze up, in our freezer.

Everything is crossed that it is a hose, but maybe i am over thinking what it could be.

I will take another bottle up with me in readiness.

I was just trying to picture the system and if i recall, it didn't look that complicated.

Doesn't help that i am only going on pictures.

 

The only moving part I can think of capable of leaking is the reciprocating water pump. There is a big seal around the piston and a fine-threaded ring/collar that can be tightened up, IIRC. This might have drained the coolant out. 

 

Also, the marina staff could be mistaken and the source of the water is something else...

 

 

 

 

[Tony Brooks]

For J specialists, does the J3 have core plugs, if they do then they would be worth having a good look at - after checking the hoses.

[Floaty Me Boaty]

51 minutes ago, MtB said:

 

The only moving part I can think of capable of leaking is the reciprocating water pump. There is a big seal around the piston and a fine-threaded ring/collar that can be tightened up, IIRC. This might have drained the coolant out. 

 

Also, the marina staff could be mistaken and the source of the water is something else...

 

 

 

 

They did send me some pictures and the water was definitely blue, also the header tank had drained.

I am assuming therefore it is from the cooling system.

I will definitely check the pump on Thursday, thank you.

Edited February 2 by Floaty Me Boaty
Typo, again

[MtB]

3 minutes ago, Floaty Me Boaty said:

diffinaley blue

 

This sounds like a lovely colour!! 

 

 

[Floaty Me Boaty]

Fingers crossed as there doesn't appear to be to many rubber hoses, but if it does transpire to be one of those bad boys, i will replace them all.

I have also sent Tom Cauldwell an email, as he might be available to take a trip and do the job for me.

[Tony Brooks]

It looks as if it as very nice, proper nut down caps where I would have expected to see core plugs, so unless one has loosened, its gasket has filed, or very unlikely one has rusted through, they are unlikely to be the problem.

[BEngo]

If it is not a hose, my money would be  the water pump packing, provided it is the single acting type pump.  The piston tends to wear so it is hour-glass shaped, so if not left fully up or fully down water can seep past, especially if the valves are a bit tired..   The good news is that it usually only drains the engine.

 

Start it, refill the header tank with mixed antifreeze and then go round all the pipe and water joints with a sheet of big blue bog roll, or kitchen towel.  Include the core plates on each cylinder- these have a nasty tendency to rust away internally where the studs are fixed.  You will soon see which are damp.  Then look at the water pump.  The water seeps out of the packing and if leaking it can be seen running alomg the flat part between the follower ring and the ccrankcase.

 

Changing the hoses generally involves removing all the pipework on the cylinders.  It is a reet PITA.

 

N

 

 

 

[Floaty Me Boaty]

18 minutes ago, BEngo said:

If it is not a hose, my money would be  the water pump packing, provided it is the single acting type pump.  The piston tends to wear so it is hour-glass shaped, so if not left fully up or fully down water can seep past, especially if the valves are a bit tired..   The good news is that it usually only drains the engine.

 

Start it, refill the header tank with mixed antifreeze and then go round all the pipe and water joints with a sheet of big blue bog roll, or kitchen towel.  Include the core plates on each cylinder- these have a nasty tendency to rust away internally where the studs are fixed.  You will soon see which are damp.  Then look at the water pump.  The water seeps out of the packing and if leaking it can be seen running alomg the flat part between the follower ring and the ccrankcase.

 

Changing the hoses generally involves removing all the pipework on the cylinders.  It is a reet PITA.

 

N

 

 

 

Busy day on Thursday.

Thanks for the guidance, very much appreciated.

Is renewing the packing straight forward or is it a call to Tom to get him out?

I dont mind tinkering but if it is a PITA, i would rather pay someone TBH.

[MtB]

2 hours ago, Floaty Me Boaty said:

Is renewing the packing straight forward or is it a call to Tom to get him out?

 

I'd say its gonna be a whole lot easier now your engine has benn drained! 

 

 

[agg221]

2 hours ago, Floaty Me Boaty said:

Busy day on Thursday.

Thanks for the guidance, very much appreciated.

Is renewing the packing straight forward or is it a call to Tom to get him out?

I dont mind tinkering but if it is a PITA, i would rather pay someone TBH.

There are core plugs to check in both the cylinders and the heads. Fortunately they are pretty obvious. The plugs in the cylinders are Monel so they don't rust, but the cylinder around them can so you are checking the edges rather than the middle. If your engine is fairly well wiped down with a slightly oily cloth on a regular basis it should be fairly easy to spot where the water is coming from.

 

When you are checking for leaks, don't forget to check under the exhaust manifold, particularly at the stack end out through the box. The original raw water cooling system passed the water through here as a silencer so it depends on how it has been capped off as to whether that is relevant.

 

The pump is not too difficult to deal with, but it depends on what the issue is. If it just needs nipping up a bit, that is simple; if it needs re-packing it is fairly obvious how to disconnect the piston and take it out, but you do need the right sized gland packing material.

 

Alec

[Floaty Me Boaty]

Morning All,

Thanks very much for all your guidance, very useful.

Also spoke to Tom (Langley Mill) and he has instructed me how to check the heads, just in case the worse case scenario has made a visit and one has cracked.

I did come across some packing in the toolbox, that was left by the previous owner, but until i get the pump piston out, it means diddly at this moment in time.

Off to pick up some Blue Antifreeze, as it does not contain any nasties, then start printing off your notes and readiness for my trip on Thursday.

 

God, i wish there was a workshop manual around 🙂 

[BEngo]

The original water pump packing was 3/8 in sq.  The piston diameter was 2 in and there is only enough room for two packing rings.  That means you need about 18 in of packing to do the job.

 

It is easier to get the piston back in if you slightly flatten the packing before fitting it.  The follower will bring it back to shape when you tighten down.

 

N

[Floaty Me Boaty]

4 minutes ago, BEngo said:

The original water pump packing was 3/8 in sq.  The piston diameter was 2 in and there is only enough room for two packing rings.  That means you need about 18 in of packing to do the job.

 

It is easier to get the piston back in if you slightly flatten the packing before fitting it.  The follower will bring it back to shape when you tighten down.

 

N

Thanks for the info.

I will double check the quantity on Thursday to ensure i have enough.

Is it as simple as releasing the ring and the piston will come out at the top?

[BEngo]

Yes, but

Have a look at ghe parts book to see how it all goes together.

 

Set the WP crank at TDC.  Undo the locknut on the connecting rod.

Undo the ring

Unscrew the piston rod from the connecting rod

Push the piston down.  Rock  the conn rod out of the way.

Pull piston and piston rod out.

 

Reverse to reassemble.  You may need to turn the engine to move the conn rod back down before the piston rod will screw in.

 

N

[Floaty Me Boaty]

3 minutes ago, BEngo said:

Yes, but

Have a look at ghe parts book to see how it all goes together.

 

Set the WP crank at TDC.  Undo the locknut on the connecting rod.

Undo the ring

Unscrew the piston rod from the connecting rod

Push the piston down.  Rock  the conn rod out of the way.

Pull piston and piston rod out.

 

Reverse to reassemble.  You may need to turn the engine to move the conn rod back down before the piston rod will screw in.

 

N

That's great, thank you once again.

I will check the toolbox first to see if there is the correct packing in there, and to obviously get an idea to what it looks like.

Water Pump.pdf

[BEngo]

The pdf you posted is for the double acting pump.  This has leather cup washers ( scarce!!) to do the pumping , and I don't think they had any packing but  I have never had one apart either.  There does apear to be some packing round the piston rod.  

 

Most engines have a single acting, and simpler pump.

N

 

 

[Floaty Me Boaty]

Wasn’t too sure if it was the correct pump and on talking to Mike, it is wrong and he hasn’t any drawings of a J Series pump. 

[BEngo]

A thought has ocurred.  I think it would be worth looking at the two water pump  valves whilst you are re packing the ram and have the water drained.  Access them by unscrewing the covers on either side of the pump.  There is a spring and a valve underneath each.

 

Nothing to do with any leak, but saves buying more antifreeze in future.

 

N

[Floaty Me Boaty]

1 hour ago, BEngo said:

A thought has occurred.  I think it would be worth looking at the two water pump  valves whilst you are repacking the ram and have the water drained.  Access them by unscrewing the covers on either side of the pump.  There is a spring and a valve underneath each.

 

Nothing to do with any leak, but saves buying more antifreeze in future.

 

N

Spoke to the previous owner yesterday and he has assured me that there is a bag with all spare bit and bobs in the toolbox.

Not sure what i will find, but fingers crossed.

Edited Tuesday at 10:52 by Floaty Me Boaty

[Floaty Me Boaty]

Something else i noticed, but TBH I didn't pay a lot of attention too at the time, and that was when i opened up the Test Cock, i did notice lots of air in the water being emitted.

Reading the Kelvin notes, it does say it should be a steady flow.

One never knows.

[Floaty Me Boaty]

Hi All,

Thursday's visit was eventful.

Once i had cleaned all the water up and dried her out, i went through all the checks recommended by you all, thank You, and once i had refilled her, i could hear a spitting noise when turning her over.

 

On further inspection, the Drain Cock on the pump had somehow been knocked open.

 

All other checks were good apart from the fact i couldn't find any pump packing in the toolbox.

 

I will contact Tom later today to see if he can come down and re-pack the pump as it is no good me stripping it down on Monday, only to find i cannot finish the job.

 

[Tony Brooks]

May I just thank the contributors to this topic for some very educational posts.