Power steering noise

[David Anderson]

I've got a bad whine in my steering until the bus warms up.  I checke the fluid and added Dexron to the mid level between the marks, started the bus and it whined and burped a bunch of fluid out the top of the reservoir.  The whining stopped and the the fluid is low again.

When we came home the steering whined again until warm.   I checked the fluid today and it isn't even at the bottom of the stick.   The bus steers fine except for the noise until warm.  What should I do to fix this?

I attached a copy of the the power steering pump diagram below in case anyone knows what the guts of the pump looks like.

David

[Cary and Don]

Been there and done that.  First we have a GM4107.  When we first go it the fluid got down a little and we added the fluid.  What a mess.  It turns out that they had been using hydraulic oil in it and we added the power steering fluid on top.  It boiled out this pink foaming mess.  We figured out that there was hydraulic oil in there and refilled with that.  It took a couple times for all the pink to disappear.  We have had it for seven years.  It still howls when cold and clears when warm.  Don't know if that will need to be fixed at some point, but it hasn't caused any problems for us so far other than the loud noise.

Don and Cary
GMC4107
Neoplan AN340

[desi arnaz]

i get the same noise when cold.......

[luvrbus]

David, have you changed the filter in the reservoir and are you sure you engine has the Eaton pump

good luck

[hargreaves]

Try using Transynd trans fluid, it is less viscious at low temps and tends to be much easier on pumps. We used to use hydraulic fluid on our transits and found that when cold the fluid did not want to move and caused cavitation. It actually got so bad it would suck engine oil into the power steering system. since changing no noise and longer pump life.   Good luck,   Gerry.

[David Anderson]

David, have you changed the filter in the reservoir and are you sure you engine has the Eaton pump

good luck

I changed the filter about 20k miles back.  I don't know what kind of pump I have.  I have never had to do any service on it.  How can I find out?  It looks just like the one in the attached picture link from my post above, and I have always used Dexron; however, when I couldn't find Dexron II and switched to III, that may have been when the noise started, but I don't remember.  I'm more concerned about the upchuck of fluid all over my rear bumper.  It's a mess.

David

[Barn Owl]

When my old pump went bad it kept throwing it's oil out. I hope that is not your problem. Sheppard tech support says to use 40wt oil in my system and they where quite insistent on it. I have trouble with it whining loudly when cold but it goes away when warmed up. I am still temped to convert to a lower wt. oil.

[TomC]

Sheppard said to use 15w-40 in mine.  It whines when cold, but can't hear it when warm, only when turning hard over.  Good Luck, TomC

[PSmith]

Mine is marked with '10w-30w only' and was noisier when cold..   Found that the suction side of the pump had a 'questionable' o-ring and was allowing 'sucking air'.  Changed o-ring and eventually the air worked it's way out and the whining is now only when cold and turning hard.  Normal turning after warm-up, it's pretty quiet.  Just my 1 cent.
Phil

Mine's a Vickers --

[luvrbus]

David has Ross steering on his Eagle and they used 2 different pumps the Eaton he posted uses Dextron if a seal leaks it will leak to the outside and the Vickers uses 15/40 if it leaks it will leak to inside the engine

good luck

[roger dolan]

   Make sure that your supply line is big enough to supply the pump. When they whine it means the pump is starving for oil. I put a larger suction line on my 4106 and that solved the problem.


                                                Roger 4106

[desi arnaz]

where is the suction line and how hard was it to change?

[DaveG]

Generally the suction or low pressure side supplies oil from the reservoir to the pump. The pressure or smaller of the two lines is the pressure or output from pump to the steering gear.

Suggest you determine what pump you have first.