power steering fluid blowing overboard

HB of CJ · September 09, 2013, 11:01:56 PM

This is unrelated and probably will not help but my old Crowns VT-42 Victors pump blew a seal, (is this possible?) overheated, and pumped out most of the fluid during a trip from Apple Valley Ca to Cave Junction OR about 11 years ago. Ancient history...but...

There was very nasty oil all over the engine and bulkhead walls. Hot pump. Since I had made the trip non prepared, I had no spare parts or tools to speak of. I cut the remaining belt, (one had disappeared) and drove the bus home with manual steering.

Removed and took the VT-42 pump to the Grants Pass OR hydralics shop up by the RR tracks and the young guy looked at the pump and then got the old guy. He looked, examined and thought for a bit and told me I had the wrong pump for my application.

Sixteen thousand pound front axle. TRW power assist manual steering gear. I needed a bigger pump which he swapped with the existing pump as a core. Also got bigger Gates commercial matched belts. Also one of the very long hydralic hoses had a pin hole leak at a brass joint. They swapped pumps and made up two new hoses as I waited.

Had a local mechanic install and purge the trapped air from the axle cylinder. Then the power assist steering could be turned with one finger actually slightly lifting the bus a little bit from R lock to L lock. Quiet. Powerful. Seems the school district...

...had just installed whatever pump they had in stock so they could auction off the 1974 Crown Supercoach 10 wheeler. For me it took the right guy with the right knowledge to understand that my existing pump was too small. Hope this helps. HB of CJ (old coot)

David Anderson · September 10, 2013, 05:13:35 PM

Quote from: akroyaleagle on September 09, 2013, 07:45:02 PM
David,

The pump cannot return more fluid than it takes out.
It may be pumping air through a supply side leak and returning that.
Good Luck and let us know what you find.

Makes sense, but.... why does it only do it when cold? The awful grinding noise it makes when cold is really loud. After warmup all goes away. Steering is not any more difficult cold or hot. Only the noise and blowing out the canister seal is the difference.

In the past it would blow it out the dipstick seal. I fixed that and now it blows it out the reservoir seal. The can is not supposed to be under pressure right? It should be equal in and out I suppose.

Are there any check valves or pop off valve on the steering gear that possible contract open when cold and close when fluid heats up? If so, it seems it would blow out at that point, not suck air.

Thinking of the physics of the system it really seems like a restriction on the suction side that somehow relieves itself when heated up. I'll chase that theory first.

I couldn't tear into it today as I'm helping my son frame his house. I may have some time tomorrow afternoon.

Geoff · September 10, 2013, 06:32:13 PM

Blowing oil out the power steering pump is a classic indication that you are sucking air in the system, and if it goes away after it warms up, the seal has warmed up and started working. Bypass the power steering ram and see if the same problem happens, if so, it is your pump.

--Geoff

David Anderson · September 10, 2013, 07:19:45 PM

Quote from: Geoff on September 10, 2013, 06:32:13 PM
Blowing oil out the power steering pump is a classic indication that you are sucking air in the system, and if it goes away after it warms up, the seal has warmed up and started working. Bypass the power steering ram and see if the same problem happens, if so, it is your pump.

--Geoff

Where is the seal? Is it in the power steering gear under the steering wheel (Ross Steering gear (HB) model) (I think) or is it in the pump on the engine? Bear with me, I'm a neophyte at this

Also, how do I bypass the steering ram?

Geoff · September 11, 2013, 08:56:09 AM

I suspect the steering box. Bypassing the box is hooking the feed and return lines together (with adaptors). If you bypass the box and there is no air in the pump you have narrowed down the problem to the box. It may or not be rebuildable.

--Geoff

luvrbus · September 11, 2013, 09:28:37 AM

Its a easy check for air in a system on a Eagle just check the fluid level start the engine then turn the engine off check it again if the fluid level rises it has air trapped in the gear if that accrues they have a bleeder valve on the gear.

The fluid level should always be above the return line in the reservoir or they just keep making air first he needs to figure out if he has a Vicker or a Eaton pump on his Eagle the Vickers pump runs off the blower and the Eaton will run off a auxiliary drive on the bell housing on his Eagle

His Houston Metro Eagle has Ross (TRW) steering he can download a trouble shooting guide from TRW for free

David Anderson · September 11, 2013, 03:07:15 PM

I have an Eaton pump. I may have found a problem. The pipe on the side of the reservoir has its hose attached to the pump bowl reservoir sub assembly on the side of the Eaton pump (the one with the hose clamp on the pump picture.) I think that hose should be connected at the reservoir bottom fitting instead. It seems the pump would suck from the bottom fitting of the reservoir and return the flow to the side inlet on the reservoir.

Is my plumbing hooked up backwards?

I purged all the ATF from the lines with air pressure about 2psi so the whole system is empty. My air hookup was at the steering gear on the hose that returned to the reservoir. I noticed that the air was pushing through the bottom fitting of the reservoir and bubbling out of the center stem. The center stem sits inside the filter. This is why I think it may be plumbed backwards. Shouldn't the filtered oil be sucked into the filter media from outside in then downward to the bottom of the reservoir, out to the pump, then to the steering gear, then returned to the reservoir via the higher inlet?

I had the steering gear overhauled by BAB steering in 2003 for just under $1k. They sent me an instruction sheet urging me to use 15w40 motor oil instead of ATF. I didn't do that. The Eagle manual list ATF as the fluid choice.

Should I switch to motor oil? What do most of you guys use in these Ross HF steering gears?

luvrbus · September 11, 2013, 03:20:13 PM

The pump in the picture is a Eaton B 800 gear driven pump it has no coupling and it uses rollers instead of vanes to pump, maybe time to call Strightline Steering on that one he will need to know if it is driven off the passengers side or drivers side looking from the rear of the engine

A good feature of that style Eaton is if a seal blows they leak to the outside of the engine not to the engine oil

Ed at Jefferson will have the pump just sit down and take a aspirin before he gives you a price

good luck

David Anderson · September 23, 2013, 06:54:39 PM

I finally got the 38 year old hose out to replace it. It took me 8 hours to get that thing out. Why didn't I do this when I built the conversion

I do believe they built the bus around the hose. I had a new 38' hose made and got it installed this afternoon. $317 for the hose. I'm not replacing the return hose as it has no pressure on it.

I need to decide if I'm plumbed incorrectly. I feel like I should put the pump suction hose on the bottom fitting of the reservoir and the steering gear fluid return line on the high fitting of the reservoir. (They are reversed in the picture in the earlier post.)

This is the way my radiator is plumbed and I suspect the power steering system should be the same. This would force fluid into the reservoir on the outside perimeter of the filter in the can and send the fluid though the filter outside to inside, then it would be drawn through the center stem of the can and sucked out the bottom of the can via the bottom fitting back to the Eaton engine pump.

The other decision I need to make is whether to use motor oil or ATF. I had the steering gear overhauled 10 years ago for $953 by BAB Steering. They sent a data sheet recommending 15w30 motor oil instead of ATF. The Eagle manual calls for ATF, which is what I've run in the system since. Should I disregard the Eagle book and change to motor oil? I may try to call BAB Steering and get their input.

David

akroyaleagle · September 23, 2013, 08:09:19 PM

David,

Here's my $.02.

I too have been told to run 30wt oil or 15/45wt in the transmission or P/S.

I do not believe the oil has the same ability to withstand the temps encountered.

I have ATF in both and will continue. I believe hydraulic fluid should be used where it is specified.

I would install the hoses where the Eagle Manual says to. I suspect the filter in the tank is
designed to work one way. Without going out to the shop to look it up, I think the return line should
be attached to the bottom. It wouldn't make sense that unfiltered fluid would be introduced to the tank.

Len Silva · September 24, 2013, 05:32:20 AM

Here's my $0.02. If BAB Steering says it, do it. Those guys can do no wrong in my book.

luvrbus · September 24, 2013, 05:43:57 AM

I would not use 15/40 in the Eaton pump David if you do not want the howling on a cool morning, I don't care what BAB says that is a roller pump not a vane type unlike a Vickers no way can it leak to the engine side like a Vickers if it ever leaks it will be to the outside

Sam 4106 · September 24, 2013, 08:06:32 AM

David, I agree that the lines on reservoir need to be reversed. Then they would correspond with every other system i have seen. Oil from the bottom of the reservoir goes to the pump. Try it that way. What have you got to loose, other than the labor? I believe that will solve the mystery.

Good luck, Sam

luvrbus · September 24, 2013, 08:34:46 AM

On your Eagle the suction comes out the bottom of canister it is a 1 inch suction line to the top of the Eaton canister that is just a cover on the Eaton pump you can remove that cover by removing the 2 nuts working on it I would change the large o-ring now for to avoid a future leak , then the pressure line the smaller line at the bottom of the pump that is a bitch to work on goes to the steering box then a line goes back to canister side on the back

good

David Anderson · September 24, 2013, 06:49:29 PM

I reread the BAB tech sheet and the motor oil is recommended for Sheppard gears. ATF is recommended for Ross. That answers one question.

The plumbing---The suction fitting from tank to the Eaton pump is 3/4" on the side of the reservoir. The return fitting from the steering gear is 1/2" on the bottom of the reservoir, so obviously they are not reversed and they are plumbed correctly.

I jacked up the front end, filled the tank with 2 qts of ATF to the top, started the engine and it took a total of 6 qts to keep the level up. I turned the wheels left and right, heard some whining at first then it got quiet. Lots of foam in the fluid. After I get the bus put back together I'll drive it and check levels. I've never purged the whole system of fluid before this, only drained the tank in the past. Maybe new fluid throughout will help solve my problem.

I'll repost after I get it all done.

Clifford you are right on that the fitting on the pressure side of the Eaton pump is a bear to get to. Had to take the air hose off and the governor just to get my fingers down there