Cat 310 pump leak question

[slash007]

I noticed that one of my cat 310 pumps has a small water leak coming in between the rails on the back side of the manifold. I wasn't sure if the most likely cause would be low pressure seals or maybe the piston o-ring? I've rebuilt the manifolds before, but never had a leak and wasn't sure what the most likely culprit was and wanted to find out so that I could focus more on whatever it could be. Thanks.

 

[I.B. Washincars]

I've not had any Cats for quite some time now, but whenever I had a leak like you describe, it was the plunger bolt gasket.

 

[MEP001]

It's possible the plunger bolt seal is leaking, but in my experience it's incredibly uncommon. It's more likely to be a low pressure seal.

I'd recommend replacing the seal kit and the plunger bolt o-rings, back-up rings and the copper washers. The seal kit comes with the o-rings, the rest you'll have to order separately. Check the plungers for cracks while you have it apart (Again very uncommon but it is possible).

 

[slash007]

I'll throw a seal kit in it and check the other parts. I think it's the only pump that wasn't re-sleeved,wondering if I should just replace it with one that was. Thanks for all of the information.

 

[slash007]

I took the head apart and the middle Low pressure seal came right out. It had the middle part bent outwards, so it was obvious where the leak was from. I didn't see any irregularities on the piston that would have caused that.