Bleeding the thing
Thread Starter
|
Elder User
Joined: Nov 1999
Posts: 796
Likes: 3
From: Anderson Northern Ca
Bleeding the thing
Just installed a new 78 1/2 ton 4x4 steering box,new pump, new hoses, new oil cooler and a new in line oil filter. The problem is I cant get all the air out of the system.With the resivoir to the full level and the cap on ,the oil level drops completely until it starts sucking air when I start the truck.I followed the install instructions on bleeding the pump,spent 4 hours turning the steering wheel back and forth to expell the air. After the oil level drops I shut the motor off and the oil level came right back up to the full mark.This tells me that the oil is compressing the air when the pump is running and as soon as I turn off the motor the compressed air is pushing the oil back up to the resivior.Can anyone give me an idea of how to rid the system of air or am I missing something,there are no leaks whatsoever in the system.I started this project almost 1 year ago and would really like to finish it the right way, thanks in advance.
Cargo Master
Joined: Jul 2000
Posts: 2,281
Likes: 18
From: Northern California
Bleeding the thing
I'd make sure the nothing is higher than the pump as that might trap air. If you run the pump, do you see any air comming up in the fill area? It's hard to imagine that air is stuck in there. I'd also check for small leaks or cracks in the line or housing somewhere.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Bleeding the thing
Nod, Do you have to have the engine running to do this? Have you tried lifting the front wheels and turning them with the engine off? I think I did some of both.
John
jowilker
Club FTE since 01 01
66 F100s
In the still cool hours of the night,
you can hear chevys rusting away.
John
jowilker
Club FTE since 01 01
66 F100s
In the still cool hours of the night,
you can hear chevys rusting away.
Thread Starter
|
Elder User
Joined: Nov 1999
Posts: 796
Likes: 3
From: Anderson Northern Ca
Bleeding the thing
Thanks KarlJay and John,I bled the system with the wheels off the ground with the motor off for 3 hours and with it on for short periods for an hour and still the same end result.There are no cracks or leaks whatsoever anywhere in the system.I am driving my F250 to work and will try the 4x4 again tonight,thanks for the help.
"bowties in the rearview mirror"
"bowties in the rearview mirror"
Senior User
Joined: Dec 2000
Posts: 435
Likes: 0
From: Nebraska Farm
Bleeding the thing
If you don't mind a little bit of a mess, crack the lines going into steering box from the pump and run it a little bit (a few seconds should do it). If there is an air lock, you need to relieve it somehow. Wrapping a rag around the fittings keeps oil from spraying everywhere. Also, make sure your hoses arene't kinked or plugged, even though they're new, you never know. I replaced my steering box this summer and recall having the same strange thing happening.
Dave,
79 F-150 4x4, 390 w/C6, Edelbrock carb, 33X12.50 never will be finished.
Dave,
79 F-150 4x4, 390 w/C6, Edelbrock carb, 33X12.50 never will be finished.
Thread Starter
|
Elder User
Joined: Nov 1999
Posts: 796
Likes: 3
From: Anderson Northern Ca
Bleeding the thing
Thanks Dave and everyone else , I finally found the right answer at Steering Systems By Benchworks, they were the shop who rebuilt the box in the first place.Pat the owner said to lower the truck to the ground and start the motor,check the fluid level and allow the system to come up to normal operating temperature.The reason a PS. box wont bleed while the wheels are in the air is that they have to be on the ground to provide resistance so the metering valve inside the box will open.Once the system is warmed start turning the wheel a little at a time and keep an eye on the fluid level.I did this for an hour with great results, I had to remove some oil from the resivoir when I was done to get the correct oil level.When you are working the air bubbles out dont fill the pump too full, just keep the oil level at the bottom of the filler tube so it wont suck air.Also recommended was leaving the steering wheel turned to the left overnite,this allows air to escape thru the valve system and out of the box. It works great, dont know how I got
along without it! "bowties in the rearview mirror"
along without it! "bowties in the rearview mirror"
