Hemi Swapping a perfectly good 70 Duster
I'm fairly confident I have my power steering issues resolved. Ultimately, I think there were 3 problems, 2 of which were caused by my ignorance/neglect. While this is frustrating, it was a learning experience I didn't know I needed. @Dantra was kind enough to ship me his power steering analyzer to determine my pressure and flow. This was a huge help and now I owe him some beers!
Problem #1: The pressure valve is advertised to be 800-850psi and the turn 1 flow valve was supposed to be 2.5gpm. After using the analyzer, I found I was at 800psi and only 2gpm. Note that I had already drilled the flow valve out slightly. No telling what it was prior to that. I was able to find some data on the steering rack I have, which states it will operate with pumps that output 1200psi and 3gpm. Now I had a target, I just had to get there. I removed the two small shims on the pressure valve and that got me to 1000psi. Instead of buying pumps and robbing valves, I came up with an idea to increase the spring tension on the valve that would result in higher pressure. This is what I came up with. A 6-32 screw fit inside the spring and regulator body perfectly. I just ground the head flat so it would sit right. This resulted in around 1200-1300psi. Good enough for me. Next up was the flow, which was easy. I just chose my next size up drill bit. This resulted in 2.5gpm at idle and 3gpm at high RPM. Nailed it!
Problem #2: I was confident my new pressure and flow had fixed the problem, but it didn't. I went for a drive and it almost seemed worse. The problem also showed up with doing some high RPM pulls, which made me think the pump was cavitating. I get home to see the suction hose has a section that looks collapsed. This is where my neglect shows up. In my haste to get this thing done, I didn't put much thought into what type of hose I needed, nor did I inspect the type of hose the parts store supplied to me. It was heater hose. No Bueno! I found the proper hose locally and replaced it. Again, I was confident it was fixed. Wrong!!!
Problem #3: When I pulled the cap off the reservoir, it was under a vacuum. (not a vented cap) I started doing some research and found an article about PS reservoir venting. Turns out all the symptoms of a non-vented cap are exactly what I was seeing. I really didn't want to purchase another reservoir just for the sake of having vented cap. I also searched to see if the brand tank I had offered a vented cap, which they do not. After thinking about how to accomplish a vented cap, this is what I came up with.
This is just a 1/8npt coupling that I drilled the threads out on one side. I then "turned" a nut down to fit in there (nut on all thread in a drill while sanding on a belt sander), and soldered it in. Next was a small hole through a bolt and some o-rings to seal it up. I'm planning to get one of those sintered brass pneumatic vents to put on top of the coupling. All the cavitation I was having wreaked havoc on the oil. I decided to take the pump apart to make sure nothing was damaged. All looked good, so back together it went. With some fresh fluid in the tank, I went for a ride. All seems good now. However, the fluid is still getting to 200 degrees. I'm going to install a cooler to try to lower this temperature.
I traded some emails with someone at Turn 1 steering. He was the one that told me not to fear having too much pressure. The rack will only demand what's needed. It's not like I'm going to ever hold it at full lock. He also mentioned the vented cap. They do offer a drop in pump for the G3 hemi, and its very expensive. While I'm sure there are some advantages to using their pump, I don't see why a properly dialed stock pump won't work. However, this could be my ignorance speaking again. I'm sure they install ball bearing in place of the bushings and likely have some tighter tolerances on things. Do I really need that? I don't know. Perhaps if I were road racing, but these pumps were designed to last hundreds of thousands of miles on a street car. I don't see any reason why it won't last on my weekend cruiser. I'm hoping my ignorance doesn't come stab me in the back for that statement!
I'm fairly confident I have my power steering issues resolved. Ultimately, I think there were 3 problems, 2 of which were caused by my ignorance/neglect. While this is frustrating, it was a learning experience I didn't know I needed. @Dantra was kind enough to ship me his power steering analyzer to determine my pressure and flow. This was a huge help and now I owe him some beers!
Problem #1: The pressure valve is advertised to be 800-850psi and the turn 1 flow valve was supposed to be 2.5gpm. After using the analyzer, I found I was at 800psi and only 2gpm. Note that I had already drilled the flow valve out slightly. No telling what it was prior to that. I was able to find some data on the steering rack I have, which states it will operate with pumps that output 1200psi and 3gpm. Now I had a target, I just had to get there. I removed the two small shims on the pressure valve and that got me to 1000psi. Instead of buying pumps and robbing valves, I came up with an idea to increase the spring tension on the valve that would result in higher pressure. This is what I came up with. A 6-32 screw fit inside the spring and regulator body perfectly. I just ground the head flat so it would sit right. This resulted in around 1200-1300psi. Good enough for me. Next up was the flow, which was easy. I just chose my next size up drill bit. This resulted in 2.5gpm at idle and 3gpm at high RPM. Nailed it!
Problem #2: I was confident my new pressure and flow had fixed the problem, but it didn't. I went for a drive and it almost seemed worse. The problem also showed up with doing some high RPM pulls, which made me think the pump was cavitating. I get home to see the suction hose has a section that looks collapsed. This is where my neglect shows up. In my haste to get this thing done, I didn't put much thought into what type of hose I needed, nor did I inspect the type of hose the parts store supplied to me. It was heater hose. No Bueno! I found the proper hose locally and replaced it. Again, I was confident it was fixed. Wrong!!!
Problem #3: When I pulled the cap off the reservoir, it was under a vacuum. (not a vented cap) I started doing some research and found an article about PS reservoir venting. Turns out all the symptoms of a non-vented cap are exactly what I was seeing. I really didn't want to purchase another reservoir just for the sake of having vented cap. I also searched to see if the brand tank I had offered a vented cap, which they do not. After thinking about how to accomplish a vented cap, this is what I came up with.
This is just a 1/8npt coupling that I drilled the threads out on one side. I then "turned" a nut down to fit in there (nut on all thread in a drill while sanding on a belt sander), and soldered it in. Next was a small hole through a bolt and some o-rings to seal it up. I'm planning to get one of those sintered brass pneumatic vents to put on top of the coupling. All the cavitation I was having wreaked havoc on the oil. I decided to take the pump apart to make sure nothing was damaged. All looked good, so back together it went. With some fresh fluid in the tank, I went for a ride. All seems good now. However, the fluid is still getting to 200 degrees. I'm going to install a cooler to try to lower this temperature.
I traded some emails with someone at Turn 1 steering. He was the one that told me not to fear having too much pressure. The rack will only demand what's needed. It's not like I'm going to ever hold it at full lock. He also mentioned the vented cap. They do offer a drop in pump for the G3 hemi, and its very expensive. While I'm sure there are some advantages to using their pump, I don't see why a properly dialed stock pump won't work. However, this could be my ignorance speaking again. I'm sure they install ball bearing in place of the bushings and likely have some tighter tolerances on things. Do I really need that? I don't know. Perhaps if I were road racing, but these pumps were designed to last hundreds of thousands of miles on a street car. I don't see any reason why it won't last on my weekend cruiser. I'm hoping my ignorance doesn't come stab me in the back for that statement!