Community Forums

Terry W · 10-07-2015, 10:44 AM

I have my MH in the shop for a brake fluid change and a couple of other little things.

I feel that the PS is a little under assisted at very low speeds. I realize that the system isn't designed to turn the wheels at a dead stop and it isn't good for the steering components anyway. But, at very low speeds, like tight parking situations, the steering assist won't/can't keep up and it is comparable to almost no assist. It is almost impossible to make a quick maneuver, especially a quick lock to lock turn.

Does this seem normal to everybody, does yours act like this. Maybe I'm expecting more response than it is capable of???

I talked to the guys at the shop and they said they will give it a test and take a look at things. They are curious if there is any information available for fluid pressure and flow rate.

If I understand the Hydro Max pump it supplies the brakes and the steering with power assist, just like on some cars and light trucks. Are there any adjustments that should be checked or any part of the steering assist that might not be working correctly.

I am not having any apparent brake issues, they seem fine.

I read the Bosch manuals on the ACA tech site, no real help.

Thoughts??

Terry

Old Scout · 10-07-2015, 11:05 AM

Not quite--the power brakes, power steering and the engine fan are all powered by the hydraulic pump on the engine. So--when was the last time fluid and filters were changed in your engine-powered hydraulic system??????
PS--lots of conversation about what type of fluid to use--early Alpines used ATF, some mid-age models used 15w-40 engine oil, and latest model use AW46 [like] hyd fluid.....

Terry W · 10-07-2015, 11:08 AM

Fluid and filters changed about 3 months ago. I didn't do a complete flush, just the 3.5 gals in the tank and the 3 filters. Used Dexron 111.

Old Scout · 10-07-2015, 11:26 AM

OK--pretty sure most 05s used the engine oil protocol. Many 05 owners have since gone to AW46 vs back to ATFIII to get better braking response.......
PS--note: the hydro-boost does proved back=up boost for the brakes via a 12v motor in the event of a pump or engine issue, or when the engine is not running.....

Terry W · 10-07-2015, 11:41 AM

I did a lot of reading on here and the answers were all over the board so I went with the ATF111 because of availability.

I have no issues with the brakes or not that I know of, they feel good.

So the hydro boost just provides engine off back up. Thanks, I'll remember that.

Does your steering seem to be more responsive than mine? Am I chasing a non existent problem?

Like I said, maybe I expect too much?? I would think that it would be reasonable to expect to be able to turn lock to lock fairly easy if the MH is moving at all.

Old Scout · 10-07-2015, 01:38 PM

Well--about all I can tell you is that the power steering on my 03 is not like a car--I feel like I can steer freely in tight corners--eg, in a parking lot, but I dont expect to be able to easily do a "lock-to-lock" while stopped or while inching forward???????
PS--just to clarify: the hydro-boost has two functions: 1] it is the primary means by which fluid pressure from the engine pump is converted to mechanical advantage at the brake pedal [ie power brakes]; and 2] it provides a back-up 12v powered brake boost system if there is no pressurized fluid from the engine pump......

Terry W · 10-07-2015, 02:08 PM

Thanks for the info and interest. Maybe a few others will chime in. I may be barking up the wrong tree, I'll post if the shop finds anything.

Terry

Terry W · 10-12-2015, 04:15 PM

PS update.

Just talked to the shop about my steering problem, the mechanic is in agreement with me that something isn't quite right. There is almost a total lack of assist at low speeds and standstill. We both believe there should be some kind of reaction to the steering input other than a lack of assist. Over the years I drove trucks at work and never had this kind of reaction to very low speed steering input.

They've had the MH since last Wed. and have taken care of the other little issues, but as of right now they're stumped on the steering. The plan is to get the manuf and model of the steering box and try and find the pressure and flow specs and go from there.

EngineerMike · 10-17-2015, 06:58 PM

You have a Sheppard M-Series steering gear. That manual lists the test procedure for determining if you have correct pressures. W/the gate valve on test apparatus closed, you should hear the bypass valve squeal at ~2,750psi. W/your foot solidly on the brake pedal tech should read ~1000psi back pressure created at the brake master cylinder bypass.
I had this done at a Berendsen Fluid Power shop in West Sacramento (their Spokane shop sold WRV the parts on your coach for hydraulic pump, radiator fan motor, fan controller and maybe some other hydraulic parts), cost me about $90 (min. 1 hr sop rate, test took about 45 min.) for the test. They had the test tool and used it for various machinery. IIRC they opened the line between the steering & brake boost and spliced the took in there, tho it could have been prior to the steering; knowledgeably tech should know.