Replacement pump for Front Hydraulic Control Model 41 - 14.5 gpm

Seems to be several interchange models. Get with a Vickers pump dealer and see what you can work out.

http://www.tpaktopc.net/cgi-bin/Cat_Part/Cat_Part.cgi?findPartNum=1H1340

Try Knight Hawk Supply. I was able to get parts for my 41 pump from them. Good Luck, Gary http://knighthawksupply.com/vicpistonpvb10.htm

Old Magnet and Gary,

Thank you both very much for your quick replies and for the supplier leads that you have given. I will now follow up those leads.

Regards, Robert

[quote="rjstumm"]Old Magnet and Gary,

Thank you both very much for your quick replies and for the supplier leads that you have given. I will now follow up those leads.

Regards, Robert[/quote]

Let us know what you find. I know a few other guys with #41 units in need of some TLC.

Yes B4D2, I will let you know how successful I am in replacing the pump.

Rgeards,

Robert

Old Magnet, Gary, B4D2 and others,

I have been able to refurbish the hydraulic pump in the Model 41 front mounted unit on my D2 by purchasing a cartridge kit. I bought this from Pro-Active Fluid Power in Michigan (www.proactivefluidpower.com). I found the people there to be very knowledgeable and extremely helpful. Their part number is : 912067 Vickers Cartridge Kit.

The part is an exact replacement for the one that was in my pump. However, the refurbished pump doesn't have any more pressure that the old pump had, so there is obviously a problem in the hydraulic valve unit which is bolted directly to the discharge port on the pump. I have pulled this apart and reassembled it several times and I can't see anything out of place. There seems to be three valves in total. One is obviously the releif valve and this is in its own separate casting bolted to the top of the valve unit. The other two valves are side by side within the main body of the valve unit block. Each of these has what seems to me to be a very weak spring behind it to hold it against its seat. The springs look too weak to be of any use any my suspicion is that they are not original.

Is anyone able to offer advice about how stiff these springs should be from the description I have given. Also, any advice on what might be causing the low pressure problem - the rams wou't lift the blade and with the rams disconnected from the blade and they are extended to the end of their stroke and the hydraulic pump comes under full load, it creates so little load that the diesel hardly changes note. Any suggestions?

Thanks. Robert

Hey Rjstumm,

Have you done a pressure test on the pump? It could be that the problem is in the cylinders and not the pump.

If your running Cat dozer hydraulic cylinders they have internal end of stroke relief valves. (could also be source of leakage). Need to disconnect and cap lines to get a good dead head pump pressure check.

Thanks for this tip. I have disconnected the rams and plugged the lines to and from the pump and the result is still the same - the diesel hardly changes note.

A friend has suggested that the vanes in the pump need back pressure from the outlet side of the pump to make them push out against the swept surface of the chamber that the vane hub turns in in order for the pump to operate properly. That is why I was wondering if the two valves with the weak springs that I described had anything to do with the problem. Anyway, I have to dismantle it again so I will try and study its function and see if I can understand why it is not working.

Thanks for your suggestions. Robert