Hard to turn steering wheel only while turning left

[clandr1]

I have a weird issue - my power steering pump makes a hissing noise that I can hear in the cab, but only when turning left at slow speeds. The steering wheel is also hard to turn.

When I turn right, everything is normal.

I don't have any power steering leaks. Truck is 13 years old, I'm the original owner, and it has around 198,000 miles on it. The PS pump is original.

Any ideas what I'm dealing with?

Thanks!

 

[Big Mama]

hissing is usually a leak. It may have an air bubble in it from a leak small enough to pull air in. When you say no leaks are you sayiyno drips on the driveway or you’ve been under it with a flashlight?

 

[clandr1]

Good question, I should clarify that I found fluid leaking on the high pressure line. A grounding cable that bolts to the block was contacting/rubbing the hard line and I'm assuming created a small leak.
I replaced the hard line, bled the system, and am experiencing the same problem. There is absolutely no leak (currently) in the system that I can detect.

 

[JetBlackNali]

Does your truck have the hydra boost brake system on it ?

 

[clandr1]

Does your truck have the hydra boost brake system on it ?

Yes.

 

[JetBlackNali]

Does the hissing go away when loaded(turning or braking)? If so I would look into the hydra boost unit. Buddies dodge of the same vintage with hydra boost had a very similar problem. On his it was high pressure line to brake unit. Inside the line is a teflon liner that slid out and got wedged in the brake unit. His problem was both directions on steering went south doing approx 60 miles an hour on the freeway. Scary

 

[Big Mama]

It really does sound like air lock. That bubble stays in the same place. If not are any of the steering components binding from the previous problem?

 

[clandr1]

Does the hissing go away when loaded(turning or braking)? If so I would look into the hydra boost unit. Buddies dodge of the same vintage with hydra boost had a very similar problem. On his it was high pressure line to brake unit. Inside the line is a teflon liner that slid out and got wedged in the brake unit. His problem was both directions on steering went south doing approx 60 miles an hour on the freeway. Scary

No, the hissing always occurs no matter what. The brakes are fine - no change there. A mechanic buddy is convinced I need a new steering gear box, because he thinks there is a failed valve or something inside of it.

It really does sound like air lock. That bubble stays in the same place. If not are any of the steering components binding from the previous problem?

I checked tonight and the steering components do not bind. I jacked up the front end and turned lock to lock 20+ times, and the wheels moved freely. Once it was back on the ground, the stiff left turn & hissing came back.

 

[Big Mama]

Then your friend is probably right. If there’s no weight on it and it works fine that kinda rules out the pump and lines. I hope he’s right. Please report back once fixed for the next guy.

 

[clandr1]

Will do!