Jet Pump Pressure Test Question

[MoDawg73]

Hello all,

In the course of rebuilding my 99 GTX Ltd, I pulled the jet pump cone off, and out came a couple of ounces of water, separated from some really black, icky smelling oil.

I am trying to figure out if the pump needs to be rebuilt, because I don't have a press to do it with.

I pressure tested it, and it was at 8 PSI after 10 minutes. I know the manual says it should hold 10. Now when I tested it, I had not applied any loctite on the cone o-ring, which I had planned to do when re-assembling for good.

What do you guys think? Do these symptoms warrant a complete rebuild? I sprayed some soapy water around the cone and the fitting and found no bubbles.

If I decide to not rebuild, what are the realistic risks that I face?

If I decide to rebuild, should I install a new wear ring as well? It has good clearance (Around .7 MM), but I am not sure how far into the useful life that would represent.

Thanks for any wisdom you can pass along!

Ken

 

[cncsignman]

If you had water in the cone, you should replace the seals. Would also check the bearings and replace if any signs of wear. You shouldn’t lose any pressure after 10 minutes. Water in the bearings will lead to a seized pump.

 

[MoDawg73]

Thanks! That's what I was afraid of!
Ken

 

[etemplet]

Just change the seal and check the surface where the seal rides. Flush the housing out really good and give it a keen eye.

If you have water in there the seal is leaking and it won't heal itself it will just get worse.

 

[etemplet]

What tool are you guys using to remove the seal on the jet pump? I've never had much luck with using a seal puller and always end up making my own tool or improvising. Since I'll be doing a number of these it would be cool if I could find a good tool that actually worked effectively. Or I'll have to actually put some effort into making another tool. LOL Help is appreciated.

Good luck in your endeavor !! Be careful damage the lower bearing trying to get the seal out.

 

[Chester]

If you had water in the cone, you should replace the seals. Would also check the bearings and replace if any signs of wear. You shouldn’t lose any pressure after 10 minutes. Water in the bearings will lead to a seized pump.

He said the water was separated from the oil. The 155mm pump cones have an outer cavity that water accumulates in. This is normal and separate from the oil.

Chester