LQ4 Hydro booster problems

[Bobbyh68]

I’m using a LQ4 out of a 06 Silverado HD that came with hydro boost from the factory. I’m having trouble adding it to my 1974 C30 Chassy. I’m using the original LQ4 pump, steering box from the c30, and hydro booster from a 2004 2500. Lines are ran correctly, I triple checked line placement with the junkyard, online research and my other LQ4 swapped truck in my garage. Everything looks correct.

My problem is that after a few minutes of test running my brake pedal is depressing (like someone is pressing it) and pump starts wining likes it’s under a heavy load, and lines are very warm to the touch and my steering fluid is burned.

Acts like a line is blocked or lines are routed wrong. Has anyone ever experienced this?

[bs46488]

I had the same issue with the pedal depressing.

Mine was resolved with more bleeding of the PS system. In my case, it took a lot of bleeding for the system to stabilize

[Bobbyh68]

I forgot to mention I’m on my 2nd booster. Thought that was the problem.
Also noticed some people “T” the return lines together. Might not hurt to try this. Might help bleed the system.🤔

How do I bleed the system?

[mongocanfly]

I swapped out all my hydro stuff and had no issues with having to bleed...put a pic up of how you have it plumbed...

[mongocanfly]

My hydro pump has 2 return ports in reservoir....I've read some people have issues with foaming g fluid when t-ing the lines...and some dont have any issues...bleeding is done by turning the steering wheel lock2lock

[bs46488]

My LS steering pump has 2 return lines for hydro boost

I did the lock to lock with the steering wheel both with the vehicle on the ground and the front wheels up in the air.

[Bobbyh68]

Thanks, Bleeding it seems to be working!👍

[Bobbyh68]

I do have a p/s cooler laying around,(junkyard is like a candy store) I’m going to add it to my system. Thanks again for the great information.😎

[BR3W CITY]

Are you running a cooler on the PS system? Under heavy load (full lock strain) the system might whine a little, which is normal. For example, don't sit with your wheels full locked while turning out of a parking space etc for long periods of time.

Even under low load tho, the system generates a deal more heat than a vacuum PS system. If your under load at all times, then there is either a mechanical malfunction, blockage etc.