Having some problems with my hydroboost/steering.
Finishing up my Nv4500 swap, I switched to hydroboost brakes and hydro clutch. The clutch I'm satisfied with how it works. The steering and brakes are giving me some fits now though. I bled out the system (wheels in air, pump brake pedal several times, cycle wheel lock/lock 20 times, refill pump, repeat). Did that procedure several times till the pump wouldn't take anymore fluid, then briefly started motor and shut down. Topped off pump and bled system again a few times (engine off), restarted motor and topped off agian. I'm fairly sure I got the air out as it got to the point where it wouldn't take any more fluid, engine running or not.
I did have some initial problems bleeding, which I assumed was because I had the two return lines "T'd" together. I pulled the "T" out and welded in another return fitting in the pump. It's at the same height as the other one.
Moving the truck around the yard, steering worked great and brakes worked awesome. I could turn same as before I started changing parts.
Problems started showing up with the road test I did earlier tonight. Taking the first corner after leaving my driveway I had a hard time turning to the left. Like no assist at all, but I could still turn. Going down the road about 2 block I had to stop. Brake pedal didn't come back up all the way and was draging brakes. I couldn't pull it back up either. Turning this time (again to the left) I had no assist and after about half turn of the steering wheel....it wouldn't go any further. Had to back up and do a multi point turn. Brake pedal eventually came back up but the steering only got worse, didn't matter which way I turned, but seemed worse to the left. Once I got back to the yard and up to the barn the brake pedal stayed down again and I couldn't move it. Steering pump never made any noises and was full the entire time. We checked it while idling and once I shut it off.
Let the truck cool down for about two hours and fired it back up to move it in the barn for the night. Steering worked ok and brakes worked just like they should.
Any thoughts? Air still in the system? Bad pump? Bad box? Bad hydroboost unit?
Some things that struck me as odd when I was bleeding the system. The lines were getting real hot real fast. Even with the front end in the air. After about two minutes of running they would be too hot to touch. This got much better after I put the second return fitting in the pump (this issue is what led me to believe the "T" was a reatriction). When turning the wheel with the engine off, I would get some fluid pushing out of the pump. I figured air working it's way out. When I first started the motor and topped off the fluid, upon shutting it down....I had a lot of fluid come back out the pump.
A little about my parts. Pump is new (well re-man). Maybe 4 hours run time on it. But, even before I put the hydrobosst in I wasn't too happy with the ammount of assit I was getting. Hole in fitting is drilled out to 5/32(?....whatever the west texas site recomends). Crossover steering with Ord parts. My steering box is drilled/tapped for hydro assist, but those are plugged. I didn't mod the box, so that is another wild card. In the past I've had to steer with no assist and its been a bear. To the point where you almost can't turn the wheel regardless if the truck is moving or not. Front end is welded and had drive flanges on for the road test (4wd or 2wd didn't make and change). I realize that a locked front end will steer hard, but at times I literally can't move the steering wheel. Hydroboost parts came from a member here, and I'm assuming those are good. I have the lines hooked up correctly(going to double check that tomorrow). Running regular power steering fluid, not ATF. When running it looks very thin and watery. I've heard switching to tractor hydraulic oil will help.
I'm going to try a different pump tomorrow and possibly try bypassing the hydroboost with a regular powersteering presure line, just to try elminating that. I do have another 2wd box I could try, or for that matter a 4wd one and putting a stock draglink/kingpin cap on.
I have some thoughts as to what it could be, but would like some other opinions on it too.
Finishing up my Nv4500 swap, I switched to hydroboost brakes and hydro clutch. The clutch I'm satisfied with how it works. The steering and brakes are giving me some fits now though. I bled out the system (wheels in air, pump brake pedal several times, cycle wheel lock/lock 20 times, refill pump, repeat). Did that procedure several times till the pump wouldn't take anymore fluid, then briefly started motor and shut down. Topped off pump and bled system again a few times (engine off), restarted motor and topped off agian. I'm fairly sure I got the air out as it got to the point where it wouldn't take any more fluid, engine running or not.
I did have some initial problems bleeding, which I assumed was because I had the two return lines "T'd" together. I pulled the "T" out and welded in another return fitting in the pump. It's at the same height as the other one.
Moving the truck around the yard, steering worked great and brakes worked awesome. I could turn same as before I started changing parts.
Problems started showing up with the road test I did earlier tonight. Taking the first corner after leaving my driveway I had a hard time turning to the left. Like no assist at all, but I could still turn. Going down the road about 2 block I had to stop. Brake pedal didn't come back up all the way and was draging brakes. I couldn't pull it back up either. Turning this time (again to the left) I had no assist and after about half turn of the steering wheel....it wouldn't go any further. Had to back up and do a multi point turn. Brake pedal eventually came back up but the steering only got worse, didn't matter which way I turned, but seemed worse to the left. Once I got back to the yard and up to the barn the brake pedal stayed down again and I couldn't move it. Steering pump never made any noises and was full the entire time. We checked it while idling and once I shut it off.
Let the truck cool down for about two hours and fired it back up to move it in the barn for the night. Steering worked ok and brakes worked just like they should.
Any thoughts? Air still in the system? Bad pump? Bad box? Bad hydroboost unit?
Some things that struck me as odd when I was bleeding the system. The lines were getting real hot real fast. Even with the front end in the air. After about two minutes of running they would be too hot to touch. This got much better after I put the second return fitting in the pump (this issue is what led me to believe the "T" was a reatriction). When turning the wheel with the engine off, I would get some fluid pushing out of the pump. I figured air working it's way out. When I first started the motor and topped off the fluid, upon shutting it down....I had a lot of fluid come back out the pump.
A little about my parts. Pump is new (well re-man). Maybe 4 hours run time on it. But, even before I put the hydrobosst in I wasn't too happy with the ammount of assit I was getting. Hole in fitting is drilled out to 5/32(?....whatever the west texas site recomends). Crossover steering with Ord parts. My steering box is drilled/tapped for hydro assist, but those are plugged. I didn't mod the box, so that is another wild card. In the past I've had to steer with no assist and its been a bear. To the point where you almost can't turn the wheel regardless if the truck is moving or not. Front end is welded and had drive flanges on for the road test (4wd or 2wd didn't make and change). I realize that a locked front end will steer hard, but at times I literally can't move the steering wheel. Hydroboost parts came from a member here, and I'm assuming those are good. I have the lines hooked up correctly(going to double check that tomorrow). Running regular power steering fluid, not ATF. When running it looks very thin and watery. I've heard switching to tractor hydraulic oil will help.
I'm going to try a different pump tomorrow and possibly try bypassing the hydroboost with a regular powersteering presure line, just to try elminating that. I do have another 2wd box I could try, or for that matter a 4wd one and putting a stock draglink/kingpin cap on.
I have some thoughts as to what it could be, but would like some other opinions on it too.
