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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: John Z on July 18, 2008, 05:40:55 AM

Title: Power steering fluid for a 4104?
Post by: John Z on July 18, 2008, 05:40:55 AM
My manual says to use AQ-ATF for the power steering system. Does anyone know what a modern day equivilent would be?
Title: Re: Power steering fluid for a 4104?
Post by: tekebird on July 18, 2008, 05:49:33 AM
if it is a sheppard power steering system, Engine oil
Title: Re: Power steering fluid for a 4104?
Post by: JohnVickrey on July 18, 2008, 09:09:34 AM
I use Type A Automatic Trans Fluid.  Buy it by the gallon if you are going to bleed the system.  When bleeding the system I usually pull the return line and pump it back into a container and then pour it back into the reservoir.  Believe me it won't steer correctly if you don't bleed it after loosing a lot of fluid.

I have the original equipment power assist. 
John V.

You guys are right it is Dexron ATF.....   A long, long, time ago in a galaxy far, far away it was Type A....
Title: Re: Power steering fluid for a 4104?
Post by: gus on July 18, 2008, 02:02:59 PM
I have the same system as John V but use Dextron because that is all I can find except Type F for Ford vehicles.

Luckily I haven't had to add more than a pint in the three yrs I've had the bus.

JV,

Where do you find the Type A?
Title: Re: Power steering fluid for a 4104?
Post by: gus on July 18, 2008, 02:40:45 PM
I posted this once but it disappeared into the net unknown! I'll try again-

Just for fun I Googled AQ-ATF and found this;

http://forums.off-road.com/jeepster-american-jeepster-club/207000-t400-t-c.html

"Since the TH400 is a GM tranny, and since the AQ-ATF was replaced by Dexron a few years later, Dexron ATF is the fluid of choice. I happen to know this because I was a Buick/Cadillac "service technician" (you know, a mechanic?) years ago, when it became Dexron ATF. (https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.busconversions.com%2Fubbthreads%2Fimages%2Fgraemlins%2Fcodger.gif&hash=1fd361bda41639d90f0ac651575e398db6c384b4)"

Based on this it appears that if GM made it Dextron is the way to go. It is also my guess that the Type A John V is buying is Dextron??
Title: Re: Power steering fluid for a 4104?
Post by: John Z on July 18, 2008, 04:09:13 PM
Hi Gus. Thanks to you and the others. I stopped by the shop where i work and asked the shop foreman. He said "Dexron ATF is what i would use." He also said later on they went to engine oil, about the time MCI was going from the 9 to the 10, was his guess.

So Dexron Type III it is.

Now on to the next challenge.

John Z
Title: Re: Power steering fluid for a 4104?
Post by: CraigC on July 19, 2008, 12:55:14 AM
John

Did your mechanic look under the bus at the front axle to see if you have a original ram type of power steering. It uses ATF. You could have a later retro fitted Sheppard or Ross intergraded steering box. I do not know what oil the Ross uses. The Sheppard uses motor oil. If he just looked at the engine compartment you can use the low pressure old style pump, but the newer style higher pressure is the proper one for a Sheppard.
Craig C
Title: Re: Power steering fluid for a 4104?
Post by: gus on July 19, 2008, 06:22:13 PM
John,

Craig has a good point. All I said is void if you have another type of steering other than the original.

The steering wheel has to be turned quite a bit before the hyd boost comes into use. In other words, while driving down a straight road you are strictly manual.

The original 4104 steering is a manual system with a hyd boost cyl. The hydraulics are completely separate from the steering gear and box. If the hydraulics fail you still have the original manual steering system.
Title: Re: Power steering fluid for a 4104?
Post by: blazing46 on January 25, 2010, 08:38:11 PM
I have a 57 pd4104 and it uses 30wt motor oil, some one put dextron in it and blew the pump seals. so I guess go by the book if they have different ones huh?
Title: Re: Power steering fluid for a 4104?
Post by: gus on January 25, 2010, 09:32:09 PM
'46,

Depends on what kind of steering you have.

If it is the original hyd boost I don't see how using the originally specified Type A (Dextron) can cause a seal to blow? Maybe there was a change from my '54 to your '57, but I doubt it.

If it is a Sheppard true PS then that is a different matter.

As Craig said, look at the front steering linkage. No large hyd cyinder means you don't have the original 4104 boost system.
Title: Re: Power steering fluid for a 4104?
Post by: TomC on January 25, 2010, 10:20:08 PM
On the Sheppard power steering in my bus, I use 15w-40 engine oil.  It hums a bit when cold, but otherwise works well. Good Luck, TomC
Title: Re: Power steering fluid for a 4104?
Post by: Nellie Wilson on January 26, 2010, 02:58:35 AM
Not to side-track here, but would GM advice apply to MCI? Mine's got the big piston /cylinder thingy, so assume it's OEM. The fluid level (sight glass) never seems to go down but, if it did, what to add?

Should it ever be drained and refreshed? And is there a filter that I should check?

Nellie Wilson