Power Steering Weak at Idle

[FightinTXag]

I swapped a TBI 350 out of an 87 burb into my '85 K10 in place of the tired Q-jet 305. My old PS pump had gotten to where it would randomly whine very loudly. So I decided I'd just leave the one from the burb on the engine and get a new pressure hose just to cover all bases.

Now, after the swap, my power assist is very weak at idle, but only once the engine is fully warm. I don't remember that being an issue the couple times I drove the Suburban, and it certainly wasn't in my truck with the old PS pump. I'm using Castrol Transynd (fully synthetic ATF).

One thing I notice is that the new pressure line seems very close to the exhaust manifold. The manifolds on my 305 were the horn style that went up over the spark plugs - usually more prevalent on cars I think. I don't think they were this close to the PS line. There's only maybe 1/4" between the new pressure line and the 350's exhaust manifold. Anyone else ever had an issue with weak steering assist because an exhaust manifold or header was heating the lines up? See pics:

The only other things I can imagine is that the pump just happened to start crapping out after the swap? Or I haven't gotten all the air out (doubtful since I've been driving it for over a week)? Or maybe the fully synthetic ATF is too thin when fully warmed up (doubtful)? I know for sure the belt is very tight - besides it'd be more likely to slip when cold, not hot.

 

[habitatxskate]

you aren't running power steering fluid?

 

[k20]

Ive always run ATF in my powersteering, but I never ran synthetic, I always ran conventional Type-F in my powersteering, never had a lick of trouble

 

[Jason4x4]

firdt, the pressure line is supposed to be routed under the return line, that will get it away from the manifold, and second, try these-http://westtexasoffroad.homestead.com/powersteering.html

 

[FightinTXag]

firdt, the pressure line is supposed to be routed under the return line, that will get it away from the manifold,

Ok, I'll try that. The PS line I was replacing was not an OE type, so I wasn't really sure about the routing. It looked like some kind of hydraulic line somebody had made. I'll try unhooking and re-routing the line.

and second, try these-http://westtexasoffroad.homestead.com/powersteering.html

I had run across that link before. (I always search thoroughly to see if I can solve my problems before starting a new thread.) Honestly, if re-routing the hose doesn't solve the issue and it's looking like the pump is faulty, I'd just as soon go spend $34 at Oreilly for a rebuilt one before experimenting with mods on a worn out pump to try to get the performance back up. I can understand doing those things to get more out of a good pump if crossover steering and huge tires is straining it. But with my factory steering setup and 235/75/15s, I'd probably be better off just swapping pumps.

 

[FightinTXag]

*update*

Well eventually the pump started whining loudly and puking fluid so I replaced it with a rebuilt one from Autozone. Now I've got plenty of assist at idle, but it starts whining very loudly once the truck warms up. I feel like the manifold is still heating up the fluid because of its proximity to the pressure hose.

While I had the pump off, I experimented with the pressure hose and it won't fit on the other side of the return hose barb. Anybody else run into this issue? Looks like Oreilly, Napa, and Autozone all use the same pressure hose - maybe it's somehow different from the factory one? Anyone have any ideas or pics of their pressure hose?

 

[Leper]

It has more to do with the location of the port on the rear of the pump. You can have a hose made pretty cheap. Does your front end move freely with the gearbox disconnected?I find it hard to believe that the manifold is heating the fluid up to that point by being that close. The fluid moves pretty fast through that area.


I would do a real good system bleed. It sounds to me like you are sucking air into the system. It only takes a tiny place for air to get in. Air would then make the pump make noise and would eventually foam up out of the top of it.

 

[FightinTXag]

By the time I got home from work last night and the brand new pump was spewing fluid everywhere. Took it off, ran it back to Autozone and picked up another one.

Went to install the 2nd new one, and it wouldn't fit. The return was different. The return tubing exited the resevoir much higher then snaked along the back of the resevoir and was tack welded in position such that the nipple was in the right place. The probelm was the tubing running along the back of the resevoir interfered with the engine block and wouldn't allow the pump to be mounted correctly.

So I pulled off the 2nd one and took it back to Autozone to get my money back. Went to Oreilly and got a 3rd new one. Oreilly claims that there's comes from Cardone and Autozones was from Atsco, but they were completely the same right down to the labels and directions in the box.

While putting the pulley and brackets on the one from Oreilly, I noticed a label that said it was necessary to pull some temporary plugs and replace them with bolts or mounting studs from the original unit. Well my core was long gone, so I couldn't see if there were bolts in those locations on my original pump, but luckily I had some bolts of the correct size/thread/length for those locations. Got it installed, filled, and bled. So far so good.

I wonder if the first pump I got might've been leaking because I neglected to do anything about those plugs? Oh well.

 

[jhellwig]

Did you used the crank pull from your 305 or the donor motor? They might be different sized and when the fluid heats up it might not be enough speed to pump enough pressure. It does also sound like you have and heat and air problem with the system. If the pump was worn out the steering box might be on the way as well.

 

[FightinTXag]

I used all of the accessories (including the ps pump) from the 350. The ps pumps were a little different (resevoirs were clocked differently), and I don't think my original one would've mounted right on the 350's brackets.

Anyway, today it worked like a champ. I think the old pump had just gone out, and I think the new one started leaking like crazy and began groaning and whining because it was low on fluid.

Oh, and I replaced the steering box about two years ago.

 

[chevy111]

I had an issue similar to this when doing one on my truck. You can use any steering pump as long as its a saginaw style. They vary greatly on where the hoses come out and have two types of reservoirs. One holds more fluid, and can be clocked deifferent ways. The autoparts stores claim they are vehicle specific but they are full of it. These pumps came on alot of years and a lot of different vehicles so they are basically universal. I ended up getting one that had the hose exit from the bottom for the return hose to clear my headers. As far as the pressure hose you can bend those pretty easily. Just use a pipe bender and bend it cleanly so it doesn't crack or kink. I did mine by hand because I only needed to bend it a about an inch and it worked fine. Heat can play a roll but more so from headers then your manifolds. You can also rig up a little shield like the one for your plugs. Hope this helps.