So here is an odd one. I have a Vintage Air Serpentine setup with a Detriot Speed power steering pump with attached resevoir. I had been tuning the efi and just today noticed that I never put fluid in the pump and had been running it dry for a while. (just idling no driving the car is not back together yet)

So I put fluid in it and it immediately started making a racket at idle, but would stop if I gave it a little gas.

All of the sudden at idle, the resevoir blew the back cover off and blasted fluid all over my freshly final block sanded car. I mean its everywhere, all over my nice clean chassis, etc. What a mess.

Anyway, what the heck caused this? This setup had been on the car for a few hundred miles before I took it apart and it only goes back together one way so the lines are not the issue. Perhaps the pump was really hot from idling a few minutes before I put the fluid in and built up pressure too fast?

Any ideas would be helpful.

Thanks

The hydraulic fluid in the pump is also the lube oil for the pump. How long would your motor last idling with no oil?

Yea, so the pump didn't blow up, the fluid container did. I know the fluid lubes the pump, but that wasn't my question. I updated the topic as I can see the confusion.

Apparently, although the cap was vented, during the manufacturing process someone never clipped the back off the rubber plug under the cap and so the resevoir had no way to vent and blew the tank. The noise was normal from the cavitation as the air escaped, but the defect in the cap did not allow it to vent, and boom.

I'm not sure about your pump, but with most new pumps you bleed them not running. You add fluid and allow for the air to escape to the reservoir. After bleeding the pump you then bleed the steering box by jacking up the front end and slowly turn the wheel lock to lock multiple times adding fluid as needed to the reservoir with it not running. By doing it this way you can allow for the larger than normal amounts of air to be safely removed with the cap off. Glad you didn't get hurt.

Thanks Bill. The first time I bled it before I took the car apart for resto was front wheels off the ground - it was running but I left the cap off so I had no pressure issue before.

I'm going to use the approach you mentioed, and yes, I was lucky to get away with a few burns on my hand.

Yea, so the pump didn't blow up, the fluid container did. I know the fluid lubes the pump, but that wasn't my question. I updated the topic as I can see the confusion.

Apparently, although the cap was vented, during the manufacturing process someone never clipped the back off the rubber plug under the cap and so the resevoir had no way to vent and blew the tank. The noise was normal from the cavitation as the air escaped, but the defect in the cap did not allow it to vent, and boom.

Aah. I see the difference now. I thought you meant the pump itself "broke". I've seen a few of them seize pretty quickly from lack of lubrication.