So at the alignment shop the other day i was turning around in the parking lot looking for a spot when white smoke and flames erupted out of my hood. Fire quickly went out but still Scared the ***** out of me. The power steering pressure hose started squirting fluid all over my headers.

Uppon further inspection, I found the O ring for the pump fitting was all kinds of chewed up looking. It had a static leak after first installation because i overtightened it and split the O ring. Changed the ring and tightened it to a little over finger tight. held up fine for a few days untill then.

My question is how tight should it be? It doesnt take much torque at all to destroy the o- ring in there and you can feel it split when you over tighten. is that normal? The line and pump are both from an 84 monte i believe. I swapped the flow conroll valve with the stock pump. If i accidently stuck the stock flared fitting on the new pump would the metric line still thread in and cause this?

Thanks for the help. I really dont need to go through any more drawers:D

The torque specification for a power steering metric o-ring fitting is 15 to 25 ft-lbs.
The torque spec for the older style 45 degree flare fitting is 25 to 35 ft-lbs.

One of the main reasons that Saginaw Steering Gear designed the metric o-ring connection was so that the assembly plants and for service in the field people could use lower torques than the 45 degree flare fittings. In 1979 Saginaw came out with rack and pinion steering gears that had aluminum valve housings. We wanted a lower torque fitting because we were afraid that people would strip the threads in their aluminum rack and pinion valve housings if they had the 45 degree flare fittings with higher torque specifications.

As you experienced the o-ring fitting will seal quite effectively even if it is just finger tight. Overtightening can cause the o-ring to be overstressed and might cause the shredding that you noted. Even with that shredding I doubt that the connection would actually leak if it was torqued back up to the 15 to 25 ft-lb spec. The o-ring connection actually does come together metal to metal. (This is what keeps the metal pipe from moving around and rotating.) The o-ring actually is a secondary or redundant seal when the connection is assembled and torqued to spec.
http://i2.photobucket.com/albums/y38/JIML82/P-PumpLeakPoints1.jpg
This picture of a power steering pump shows both type of hose connections. One thing that it correctly indicates is that the primary seal is at the o-ring or at the 45 deg flare. If there is a leak at that point, oil will leak up the nut threads or oil will leak up between the hose pipe and the inside diameter of the nut. So trying to "fix" a leak by placing teflon tape on the nut threads will not seal a leaking connection.
Jim
Jim

Great info here, thanks. So if i did accidentally put the 45* female flare fitting back in the pump, I would know because the metric o ring hose wouldnt even thread in there or seal at all right? I cant really tell if its o ring or flare by looking in the pump orifice

Actually the 16X1.5 metric nut will thread into a 5/8-18 UNF port (or vise versa). The O-ring will not seal however.

Jim

Most o ring fittings are supposed to seal with the o ring. The threads are just there to hold the stuff in postion, so the tightness of the fitting should not have anything to do with the sealing. My specific experince is that a brand F ps pump output hose will swivel when the fitting is properly tightened, and not leak. You absolutely should know which fitting type you are using. Most ps pumps can have the outlet fitting changed to whatever is desired for the vehicle. I did this when changing ps pumps on a 78 Grand Prix and a Jeep CJ with the GM pump.

Ok, well today i got a new discharge fitting from an 86 monte carlo. It looks the same as the one I have so i DO have an O ring fitting on the pump. However... When i thread in the hose to the new fitting its much more snug. The old fitting seems to have some play in the threads even when its tightened down. Im guessing there are 2 different size metric discharge fittings and i was using the larger?

There were two different size metric o-ring fittings. One fitting had a tube nut that was 16x1.5 mm the other had a 18x1.5 mm nut. You cannot make a mistake and fit one nut into the wrong metric port. The formed o-ring tube end is the same regardless of nut size.

You hose must have a 16mm nut and the tube must have the o-ring on the end in order to install it correctly into the 1986 MC discharge fitting. All GM pump discharge fittings were changed to metric o-ring starting in 1980.

Because the two different types of nuts are so close together, you can thread a metric 16x1.5mm metric nut into a 5/8-18 conventional threaded port. The o-ring tube end certainly won't seal and most likely you won't even be able to start threading the nut because the o-ring tube end is too long to fit in the port.

The opposite is also true. You can thread a 5/8-18 nut into a metric 16x1.5 threaded port. Because the 45 degree flare is a much shorter tube end than the 0-ring configuration, some people do actually install a 45 degree hose end into a metric o-ring port. They will not seal and a massive leak will result.

Hope that I was clear enough on the above descriptions.
Jim