Community Forums

prevostart · 11-03-2022, 08:53 AM

Some one I know just bought a really nice 2003 Monaco Ex, I think 42 ft. I went over there and got his Aqua Hot tuned in, And there was another guy over there working on his power steering because it did not work well at all. I stuck my head in and watched him for a few. He said that it is a Cummings ISM with red valve cover and it has one pump that did steering and fans and He gave up at that point. Another guy came and he told him the lines from front to rear were bad and needed to be replaced? How does that system work and is that normal to replace both lines? Does Monaco run lines between frame?? Or where??

jacwjames · 11-03-2022, 09:11 AM

The system probably has 2 stacked pumps, one for the fan and one for the steering circuit. The pump is mounted on the back side of the compressor.

Very seldom hear of hoses on the steering circuit going bad, they sometimes do fail causing a leak but the hoses are leaking I'd be surprised if there is a problem internally (this can happen but is rare).

There is a chance that the steering pump is bad. Only way to tell is to do a flow/pressure test.

Another possibility is that the steering box is bad. This happens more then the other issues. There are two makes of pump used, Sheppard or TRW. TRW is the better steering box and some people swap out from Sheppard to improve steering.

There are two types of Sheppard steering boxes, good ones and bad ones, seldom any in between. Good ones provide good steering with minimal wander. Bad ones result in bad steering, having to fight to keep the rig on the road. The reason is there is no adjustment on the Sheppard boxes.

The TRW have adjustments and you can rebuild, so a much better steering box.

So you need to find out what kind of problems your friend is having.

vito.a · 11-03-2022, 09:30 AM

Our 2004 Monaco Signature with a Cummins ISX uses a single large Sauer Danfoss hydraulic pump attached to the PTO. This pump drives both hydraulic cooling fans and the power steering.
I have seen some of the Cummins ISM engines use a separate engine driven power steering pump. Check the owners manual. These owners manuals are very comprehensive.

Most hydraulic hoses, A/C hoses, and electrical wires are run through the "tunnel" on the coach. In front-center just behind the front axle is an opening that runs under the floor and just above the basement compartments all the way to the rear just in front of the rear axle. You can remove the ceiling covers in the basement compartments and access this area.
It may be very difficult to remove the original hoses as they are secured in various places.
IF it requires new hoses just route them through the tunnel. But I sure would check the pump first. If the hoses are bad there will be several gallons of hydraulic fluid running out. Ours holds 50-55 quarts of hydraulic fluid.
A side note. These pumps are easily rebuilt once you track down a rebuilt kit.
Read post #7: https://www.irv2.com/forums/f115/eng...mp-467849.html