AGR pump installed; air leak? Please Help!

[ERUSH97XLT]

A cooler hopefully will help you; I hear heated fluid (not necessarily overheated fluid) will cause pumps to whine until it cools down. My pump must have super heated the fluid... mine looks like maple syrup; the fluid clearly broke down. If I remember my fluid dynamics correctly, warm and pressurized aerated fluid, when cooled and depressurized, purges air much like a bottle of pop when opened. There is probably some temperature/pressure effects within your system which causes your small (but still annoying, I'm sure) whine.

The pump should be arriving at AGR today, according to the tracking number. I'll let you guys know of their test results to honor the warranty. I'm anxious to get this done and solved! Taking the bus to work sucks

 

[ERUSH97XLT]

Warranty Honored

Just spoke with AGR, and they said the shaft seal was improperly fitted (either from the start or was dislodged), causing air to be ingested. They also mentioned that with the heavy cavitation due to fluid aeration probably destroyed the cam ring, slipper, or both, so even if I did seal the air leak, the pump would moan poorly.

All in all, they're sending me a new pump :biggthump Hopefully, everything this time works.

I'll be sure to snap some pics and note what I remember seeing on the old pump. Looks like I have labor day plans, now.

 

[ERUSH97XLT]

Forget it...

Hey, folks.

So the second pump arrived earlier than expected, so I installed it as previously described, making sure I bled the system properly and flushed the system with fresh Amsoil P/S fluid.

This pump moans like the warrantied one, but slightly quieter at high rpm

I couldn't sacrifice any more time without my truck, so I enlisted the help of a reputable mechanic. He investigated the problem, and noted the fluid discolored very quickly after a flush and fill of his own. He said the fluid turned into what looked like metallic paint, indicating metal-on-metal wear at the pump. He agreed that the procedure I followed was correct, as he does the same flush-fill-bleed procedure on every power steering pump he replaces. In short, he replaced the pump with a standard rebuild from NAPA, and everything now works as it should, no fluid aeration, no noise, just plain ol' power steering.

So, I called AGR to notify them of the same problem. They dismissed that their pump could ever possibly be at fault again (I agree, what are the odds of receiving two bad pumps?). They accused me of abusing the pump and failing to install it correctly, but my mechanic has over 50 years of experience, both in repair and performance builds, and he couldn't identify any other issue besides the AGR pump. He pressure tested the entire system without the pump with both P/S fluid and under vacuum and found no leaks. Again, it has to be something with the pump.

Needless to say, I will be returning this second AGR pump for a full refund.... and I will never think of trying this swap again.

Thanks to all who chimed in to help. I learned much more about power steering systems during this nightmare than I would have otherwise. Maybe this experience has a silver lining after all.

Regards,

ERUSH

 

[Tbars4]

...Thanks for sharing all the detailed information with this problem..:biggthump

...I posted a warning to others and a link to this thread in my AGR install thread so others can read it for themselves..

..again, Thanks..

 

[ERUSH97XLT]

No Problem, sir.

Here are some more concluding thoughts:

I left the pump with the mechanic for his own investigation, and he used his home-built test bench to see why the pump was ingesting air. He sealed the return hose barb and the high pressure port, then put the reservoir under vacuum to test for an air leak at the pump. He noted the reservoir held air as high as his hand pump would go (~25 in-Hg vacuum). This finding suggests the pump's seals are working properly, so even if fluid was running in the pump, the pump's suction vacuum isn't enough to leak air past the seals.

He then ran it with fluid on his test bench with an old, but still good, rack and pinion from a mustang. The same ingestion happened after about two minutes. His theory is that the vortex (from the high flow rate) within the reservoir is whipping the fluid before entering the pump.

We discussed his findings further, and we think that the rack and pinion system isn't large enough to support the high flow rate. Perhaps if I installed a large remote reservoir , more tubing, or choked the flow with a valve, the "whipping" would be reduced, making this pump more feasible.

I just made a 240 mile trip to Kansas City, and the rebuild pump with Amsoil P/S fluid is totally silent and works like the stock setup. No aeration, no vibration, just smooth power steering.

All in all, I do not recommend this pump for my application, the flow rate is just too high. If you figure out a way to make it work, by all means, share But, for me, I'm sticking with OEM.

 

[Tbars4]

If you figure out a way to make it work, by all means, share

..We've been playing around with our AGR pumps and may have found a solution..The party begins about post #57 of this thread...
http://www.explorerforum.com/forums/showthread.php?t=240227&page=3