Community Forums

park2832003 · 03-17-2019, 08:37 AM

Hello , i am new to the RV world. I have a 2003 Alpine coach 40'. It has the Cummings 400 ISL. the other day after sitting for a couple months i started the coach to move and level. I noticed fluid coming from what looks like a steering box on the drivers side below steering wheel. Is this the same fluid that comes from the tank at the engine it has directions that say only use Dextron II fluid? It says to check hot. Does that same tank have anything to do with the brakes? Thanks for any help Tom

Old Scout · 03-17-2019, 10:56 AM

Yes--the tank in the rear engine compartment provides hydraulic fluid for the engine fan motor, power steering, and power brake boost[but not the brake fluid for the master cylinder/calipers]. Our older Alpines came with ATF, the equivalent now is Dexron III. Tank holds about 3 gals and has three stacked filters inside. Opinions vary but I usually change fluid every 4 years [about 50k miles]….
Ps--add your coach model/year to your signature block.

park2832003 · 03-18-2019, 06:35 AM

Thanks Old Scout, the leak is not very big and i am on the road . If i keep the fluid checked would i be ok to get back home ? About 800 miles out. is there danger of not having breaks? Your help is great. First clear answer on that tank Yet. I will buy some Dextron III to keep on board.

wolfe10 · 03-18-2019, 07:02 AM

Sorry, no one can tell accurately you if the leak will stay small or a seal will completely blow out.

Yes, if you run out of hydraulic fluid, you will loose your booster part of the brakes as well as steering assist.

Not turning the steering wheel all the way to the locks will help a little by not applying full pressure to some of the seals. This is particularly true if your cut angles are not set properly and the steering knuckle(s) contact the physical stop.

Let us know exactly what steering box you have and where it is leaking for more specific information.

DrDaveMA · 03-18-2019, 07:16 AM

Submit IRV2 Alpine Registry info (see sticky above), join FMCA, ACA and ACE (Alpine Coach East)

Old Scout · 03-18-2019, 09:07 AM

Brett has it right, no sure way to tell if leak will get larger. These hydraulic components are under pretty high pressure -- 3000+psi. Assume its a Shepard100 steering gear. One owner here on IRV2 recently changed the seal on that gear, wasn't quite as easy as instructions or You-tube video but he got it done. Again, hi-pressure leaks are hard to predict--seals and connections are generally slow leakers as compared to a burst hydraulic hose for example. Try to avoid lock to lock turns and monitor at every stop--keep us posted......

Alpine06 · 03-25-2019, 04:13 PM

Hello,
I had 2 leaks of lets call it "booster fluid" (mine is actually 15W40").
So I noticed oil on top of my Generator ... tracing the wet drops back to the low pressure return hook up that is just connected using a hose clamp. I re-tighten that connection and for the last 2 trips no more leaks.
I also read through the entire Bosh manual and interesting enough there is a section for "possible leaks" and it mentioned that under extreme cold conditions that very connection could leak. Bingo I drove my rig back from MN with outside temps below zero.
A few days later moving the coach in my driveway I noticed again a spot this time a little further back. This took a bit more investigating and actually crawling under the coach ... looking at the steering gear there are 2 hydraulic connections and my top one leaked ... must have been going on for a while with all that accumulated crud. Setting a wrench on the fitting it was very noticeable that this connection was just loose. I have not driven it since but I think it is solved.
You can actually see this connection if you look through the small opening below the fuel fill.

RVPioneer · 03-26-2019, 04:04 PM

RE: 15W40. My trusted mechanic recommended using AW46. I told him the sticker on the tank said 15W40. He repeated his recommendation. It now has AW46.

Old Scout · 03-26-2019, 05:37 PM

...AW46 is a very good choice for your hydraulics--good decision....IMHO.

Alpine06 · 03-27-2019, 07:10 AM

Quote:

Originally Posted by RVPioneer

RE: 15W40. My trusted mechanic recommended using AW46. I told him the sticker on the tank said 15W40. He repeated his recommendation. It now has AW46.

And could you tell a difference in the break pedal force ?
Western RV used 3 different types of oil and researching this forum best I can tell 15W40 was only used for a short period of time. I thought about changing it but I am not clear yet to the benefit. Plus flushing all the old out will be a problem ... doable but I don’t like a mix of oil. If I do it I will try to change as complete as possible. However I have yet to read a post that tells me any benefit of doing that. Other than people say by personal preference “it’s better” ... better how ?

RVPioneer · 03-27-2019, 12:07 PM

Quote:

Originally Posted by Alpine06

And could you tell a difference in the break pedal force ?
Western RV used 3 different types of oil and researching this forum best I can tell 15W40 was only used for a short period of time. I thought about changing it but I am not clear yet to the benefit. Plus flushing all the old out will be a problem ... doable but I don’t like a mix of oil. If I do it I will try to change as complete as possible. However I have yet to read a post that tells me any benefit of doing that. Other than people say by personal preference “it’s better” ... better how ?

I’ve only driven about 25 miles since the change. The fluid is for the brake booster, so I’m not sure a change in fluid would be perceptible at the brake pedal.

My understanding of the benefits with AW46 are that the composition and additives in motor oil can lead to water emulsification, cavitation, foaming and changes in viscosity over time. That seemed like enough reasons to change.

RVPioneer · 03-27-2019, 02:40 PM

As far as flushing out the old oil, since I had to remove the oil cooler to have a leak repaired, fluid drained from both front and rear hoses. This drained the reservoir and as much as would flow out of both hoses. I also stood the cooler on end to drain its contents.

After remounting the cooler, both hoses were left disconnected while AW46 was added to the reservoir until it flowed out the front hose. The front hose was then connected and oil was added until it flowed out the rear of the cooler. The reservoir was filled after the rear hose was connected. I’m not familiar enough with the system to know where else old oil may have remained.

I’d guess 90% or more was removed. Running the engine and doing another flush while warm would probably get it close to 100%. 5 gallons of oil is about $50 and another $50 for 3 filters.