# Aster JNR C62 2 (2003) axle pump problem



## Dietrich (Dec 1, 2011)

The axle pump on my JNR C62 2 2003 version only works at irregular intervals. Sometimes it starts working at the end of a run. However more often than not it does not work at all. I have tried various ways to make the pump run but without any effect. I know of the 3 other C62 2 (2003) engines in my area who all exhibit the same problem. My question. Does anyone else have this problem. Is there a fix to it. To me the problem is most anoying when I coal fire the engine because I need all my concentration to keep the fire going.

Dietrich Dall


----------



## Phippsburg Eric (Jan 10, 2008)

I have had problem with minerals getting into the balls in the check valves (but not since using proper water). I had to disassemble the check valves, clean them and re-assemble them to get them working right. look for any corrosion. 

the easiest thing to do is to pump water through the system to flush it out. Do you have a hand pump too? does it pump water through the axle pump? try filling the boiler by pumping through the axle pump.


----------



## Dietrich (Dec 1, 2011)

Hi Eric,
Thank you for your suggestions. I have done all the things you mentioned and a few more but there has been no improvement. Lately I have come to think that the unique design of the axle pump could perhaps be the cause of the problem. T thought I might expand a bit on this topic.
The axle pump is constructed in 2 parts. There is the pump body with the piston and there is a seperate valve body. The 2 parts are joined by 2 mm copper tubing with a (M5 X 0,5mm) screw fitting at each end. The copper tubing is formed in a loop. The loop stands upright in the engine and is approx. 3 inch in legth. In addition the valve body is mounted horizontally in the engine. I thought that there could easily be an air bubble in the upright section of the loop so I went ahead and shortend this connection to less than 1/2 inch in length. However the problem is still there. The fact that the valve body is mounted horizotally also gives me some concern but there is no room to mount it vertically.
Any other suggestions would be most welcome.
Greetings,
Dietrich


----------



## David Leech (Dec 9, 2008)

Dietrich, 
I am sure that you have checked this, but I will ask anyway. 
Using the hand pump, and with the bypass open (NOT filling boiler) is there a good flow back into the tender? 
Then close the bypass (to fill the boiler) are you still able to pump water into the boiler? 
Likewise, when under steam, is there still a good flow back into the tender? 
That should show that the axle pump is doing what it is supposed to. 
And with the bypass closed, is water going into the boiler? I know, how would you know! 
If the water level does not increase, then the water has to be going somewhere, if the tender is going down! 
I find with one of my locos that I need to give the hand pump a couple of pumps every time that I stop, to make sure that the system is primed, otherwise the axle pump will not work. 
I guess that there is an air bubble somewhere that is created when stationary. 
Also, if I run really fast, it will not work properly. 
Just keep trying different tests to make sure that you can narrow down what is going on. 
All the best, 
David Leech, Delta, Canada


----------



## David_DK (Oct 24, 2008)

Hi Dietrich 

You know the C62 is the perfect machine. No errors ever ! 

Anyway. I think it might be your nice rectus connectors ..they are very small, and might stop the water from entering the pump. 
I have not installed the connectors (yet), and I dont have any problems.. (that is when the pump has been primed first) 

Best 

David, Denmark 

PS: You dont know what you will be missing at the GTG.


----------



## Dietrich (Dec 1, 2011)

David,
Thank you for your time to look into this. The first 4 questions I can answer in the affirmative. So up to this point the axle pump is doing what it is supposed to do. However when the bypass is closed there is no water going into the boiler (pressure at 2-4 Bar). Also the water level in the tender does not go down. Yes, I also believe that there is an air bubble somewhere in the system and it appears to be very dificult to dislogde it. Since we have 4 of these relatively new JNR C62 2 engines in Europe with the same problem it may time to consult with Aster.
Best Regards.

Dietrich.


----------



## Dietrich (Dec 1, 2011)

Hello David,
Sorry. I am talking about the relatively new (2003) JNR C62 2 which has this problem. This engine is totally different from our 1978 version and by the way does have the RECTUS connectors.
Yes I know, your faboulous GTG is coming up.
All the Best ,
Dietrich.


----------



## zephyra (Jan 2, 2008)

The axle pump will work differently under pressure (bypass closed) than if there is no pressure in the system. The likely culprit is the ball valve on the inlet side - this may seat adequately if there is no pressure in the system but fail if there is pressure. On the inlet side, the hand pump in the tender also has a non-return valve which is a second line of defense but a combination of air in the system on the inlet side and flexible tubing can absorb pressure from the axle pump.Seating the ball with a sharp tap through a brass rod will help.

I also have a theory that axle pumps with horizontal inlet/outlets may develop a timing/resonance problem under pressure. I have no way to prove this but what I have done is used a small stainless spring to pre-seat the ball and this seems to help and defeat another issue where the pump seems to work well at low speeds but fails as the engine speeds up. 

Robert 
@import url(http://www.mylargescale.com/Provide...ad.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css);


----------



## David Leech (Dec 9, 2008)

Dietrich, 
I would suggest that you have a look at the back head check valve then. 
If it doesn't close properly under pressure, maybe the pumps check valves are not being allowed to open so the water doesn't flow. 
JUST a theory! 
All the best, 
David leech, Delta, Canada


----------



## zephyra (Jan 2, 2008)

@import url(http://www.mylargescale.com/Provide...ad.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css); Posted By David Leech on 11 Apr 2012 09:01 AM 
Dietrich, 
I would suggest that you have a look at the back head check valve then. 
If it doesn't close properly under pressure, maybe the pumps check valves are not being allowed to open so the water doesn't flow. 
JUST a theory! 
All the best, 
David leech, Delta, Canada 

Unless there is air in the system, the water has to go somewhere  Only 4 options:

1. It goes back to the tender via the bypass valve - water level in the tender stays the same with visible flow through the bypass outlet 
2. It goes into the boiler - water level in the tender goes down
3. It goes back to the tender through the inlet valve - no visible flow, water level in the tender stays the same
4. There is a leak - water level in the tender goes down.

Hence my diagnosis of option 3. 

If the clack valve fails, then the valve on the outlet side of the pump should be a second line of defense.


----------



## Dietrich (Dec 1, 2011)

Hi Robert,
Thanks for your interesting thoughts and suggestions. Seating the ball on the inlet side of the axle pump valve is certainly worthwhile and I will go ahead and do this. I will report back a soon as I have re-seated the ball. By the way I have tried your suggestion to pre-seat the ball with a weak s.s. spring about 6 month ago but this did not help. 
Dietrich


----------



## Dietrich (Dec 1, 2011)

Thanks David,
Yes, I have also thought about a potential problem with the check valve at the back head of the boiler. I have reseated this vale more than once and eventually replaced it with a new one since multiple reseating of the valve does not seem to work well. I have noticd though that when the the axle pump is not working during a run the check valve also does not appear to work correctly because I get some hot water from the boiler back into the tender i.e. the tender water does start warming up and the pressure hose connection between tender and engine becomes quite hot. This would indicate that the outlet valve from the pump also does not seal well. 

Dietrich.


----------



## David Leech (Dec 9, 2008)

Dietich, 
I think that perhaps ALL the balls in the valves are not well! 
I know that I once saw an Aster that had the wrong size balls in a check valve. 
Maybe check the ball sizes too. 
If all else fails, maybe try some of the 'rubber' balls to see if they seat better. 
All the best, 
David


----------



## Dietrich (Dec 1, 2011)

Hello David,
Thanks for hanging in there. I have opened up the 3 valves and checked the balls. They are 3mm as they should be. Next I will remove the valve body of the axle pump and reseat the 2 valves. If this does not do it I intend to buy 3 rubber (I believe nibul) balls and try again. I will let you know.
Best Regards,
Dietrich.


----------

