Hydraulic Leak and Air Leak - 390BH

[jakedempsey]

Well, We are on our 2nd outing in the RV and I just keep learning! Today I left Kissimme KOA and the RV was bouncing like no body's business and I just learned (through this forum) I did not let the air bags inflate! I actually think it was the jacks because I pulled into Target and retracted them again and all was well. Lesson learned: Just make it a habbit to retract-all TWICE!

Now - We just got to Ft Wilderness at Disney and I have two issues I really need help with:

1. I have hydraulic fluid leaking. I saw it under the door where the pump/reservoir are so I opened the door and I had fluid in the tray under the pump/reservoir. I do not see any fluid on the lines, but I see some fluid where the reservoir is bolted to the block. I read somewhere that a lippert pump is known to have o-ring issues but to be honest I have no idea if mine is a lippert or not. I was thinking of removing the reservoir but how on earth would you do that and not spill the fluid everywhere since it is mounted horizontally? Do you have to somehow suction the fluid out before doing it? Do the slides need to be in/out when doing it? I was hoping I could take it off and clean the face (I've read that gunk can cause the seal to break) and put it back. Any advice here?

2. I have an air leak somewhere. Here is what I notice. When the parking brake is engaged the rig is nice and quiet and pressure builds to 125ish. With the parking brake off, wheels blocked, trans in neutral.. I hear a loud rushing sound near the rear of the rig and the air pressure won't rise above 75 on 1 or 2. If the tank is over 75 it will bleed down to 75 too. Also, when I press (and hold) the brake while at a stop light my air pressure keeps falling and I hear a hissing at what seems like the front. These two may be totally different issues but I could use some guidance on how to diagnose the problem. I started trying to figure out the issue because of the gauge leaking down while at a red light. Today I was backing into our spot and after a few brake uses my air alarm came on.


Our last trip we put 5,000 miles on the RV (our maiden voyage) and this trip we are going to do ~2,000. I'm very comfortable driving now, but am learning how little I know about these rigs as i encounter these issues.


Thanks for any help you guys can provide. Love this forum and I find myself searching on here all the time!

[tmmar]

You might want to look at this thread and see if it is of any help to you.

http://www.forestriverforums.com/for...ach-69347.html

Good Luck.

[Campin Cajun]

On the hydraulic leak, have someone operate the hydraulic slides in and out while you are looking for a leak around the pump. If the pump is leaking it won't take long to find the leak.

You first need to find the leak before you know how to fix it. This problem can be tied together with having to hit retract all twice. If the slides do not show the leak, then operate the leveling system.

[ResQfrog]

If you have a air leak that bad you should not be driving it at all. You most likely have a bad brake diaphragm or control valve. You will have greatly reduced braking or could have the brakes lock up due to low air pressure. A air leak this bad would be a out of service for a commercial truck. This could also get you a ticket for unsafe vehicle. get it looked at as soon as possible.

[jakedempsey]

rgmiller32 - When it is in Neutral with the parking brake released: It shows pressure at 75psi and I hear a large rushing air sound near the engine bay. Is that abnormal? I didn't know if that was a different issue than the front brake hissing when the brake pedal is held.

[jakedempsey]

Knowing that I need to get these things looked at ASAP (esp the air leak) and that I am parked at Disney... how does one actually do that? Call a local mechanic to come out to the RV? Sorry if this is a basic question, but this is my first time being out and needing something looked at. What do I even search for lol?

[jakedempsey]

Found a local Mobile Rv Mechanic - called and left a VM.. going to get an appt scheduled. Hoping he lets me be his helper so I can learn!

[Dijoeboss]

I would think if the air leak is that bad, won't take long to figure out where it's coming from. Definitely wanna get that fixed!!


2013 Georgetown XL 350
Bunkhouse
2002 F250 4X4 CC
2012 Jeep Liberty

[ResQfrog]

You need a heavy duty truck mechanic with air brake training. Make sure that the rv mechanic has air brake training. What chassis is under your coach? If Freightliner you could call them. If Spartan call them to get a number for a local dealer. Could also find a local truck repair center with road serice.

[ResQfrog]

While you are waiting for the service guy to get out to you Google FMVSS 121. There you you find info on the air brake standard and the pre trip test you should do before moving your coach. It will reference heavy trucks. But remember you fall under this if your GVWR is over 26,000 pounds.

[Superchief]

Here is a Static Air Brake Test procedure that I found:

Pre Trip Inspection Brake Check

Parking Brake Check (Pre Trip Inspection)
Apply parking brake only and make sure it will hold the vehicle by shifting into a lower gear and gently pulling against the brake.

Air Brake Check (air brake equipped vehicles only) (Pre Trip Inspection)
Air brake safety devices vary. However, this procedure is designed to see that any safety device operates correctly as air pressure drops from normal to a low air
condition. For safety purposes, in areas where an incline is present, you will need to use wheel chocks during the air brake check. The proper procedures for
inspecting the air brake system are as follows:

Test Air Leakage Rate (Static check) (Pre Trip Inspection)
With a fully-charged air system (typically 120 psi), turn off the engine, chock the wheels, release (push in) the parking brake button (all vehicles) and trailer air supply
button (for combination vehicles) and time the air pressure drop. After the initial pressure drop, the loss rate should be no more than 2 psi in one minute for single
vehicles and no more than 3 psi in one minute for combination vehicles.

Test Air Brake System for Leaks (Pre Trip Inspection)
With parking brake, (all vehicles) and trailer air supply button (for combination vehicles) released (pushed in), apply firm pressure to the service brake pedal. Watch
the air supply gauge and listen for leaks. After the initial pressure drop, the loss rate for single vehicles should be no more than 3 psi in one minute and no more
than 4 psi in one minute for combination vehicles. If the air loss rate exceeds these figures, have the air system repaired before operating.

Test Low Pressure Warning Alarm and/or Signal (Pre Trip Inspection)
Turn the key to the on position. Rapidly apply and release the service brake pedal to reduce air tank pressure. The low air pressure warning signal must come on
before the pressure drops to less than 60 psi in the air tank. If the warning alarm/signal doesn’t work, you could be losing air pressure without knowing it. This could
cause the spring brakes to activate suddenly. Only limited braking can be done before the spring brakes come on.

Check That the Spring Brakes Come on Automatically.
Continue to rapidly apply and release the service brake pedal to further reduce air tank pressure. The trailer air supply button (if it is a combination vehicle) and
parking brake button should pop out when the air pressure falls to the manufacturer’s specification (usually between 20 to 40 psi). This causes the spring brakes to
come on.

Check Rate of Air Pressure Buildup (Pre Trip Inspection)
When the engine is operating at 1800 RPM, the pressure should build from 85 to 100 psi within 45 seconds in dual air systems. (If the vehicle has larger than
minimum air tanks, the buildup time can be longer and still be safe. Check the manufacturer’s specifications.) If air pressure does not build up fast enough, your
pressure may drop too low during driving, requiring an emergency stop. Don’t drive until you get the problem fixed.

Test Service Brakes (Pre Trip Inspection)
Wait for normal air pressure, release the parking brake and trailer air supply button
(for combination vehicles), move the vehicle forward slowly (about 5 mph), and apply the brakes firmly using the brake pedal. Note any vehicle “pulling” to one side,
unusual feel, or delayed stopping action. This test may show you problems which you otherwise wouldn’t know about until you needed the brakes on the road.


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[jakedempsey]

Ok - I had a mobile mechanic come out today. We had a hole in an air hose that went to the right rear brake can! The two air lines were rubbing against each other.

Unfortunately, the mechanic didn't have the hose and left to have one made b/c nobody had it in stock. I did not realize I would have to pay for his time while he wasn't here!!

The bill was 600.00! I nearly fainted! The hydraulic leak ended up being the black valves (i think thats what they are). There were 3 that were pretty loose.

Thanks for everyone's help!

[ResQfrog]

The tow bill would have much worse if you were driving and the brakes locked up for lack of air pressure. Then add the emergency repairs on top of that.

[I-RV]

Superchief; thank you for the great information for testing air brakes. Do you know if these are the tests that trucks are supposed to do at the crest of steep downhill's which have signs and pull-over areas to do the test. I am sure with a DP, that we should be doing these downhill tests as well and was wondering what to do.

Hank

[Superchief]

Hank, Not sure about testing at the top of a grade, but when Ed (wnytaxman) took his "B" endorsement driving test for New York State, the Examiner told him he should run a static test on the air brakes before any trips. Craig


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[I-RV]

Superchief; your mentioning of the "Class - B" license brings up an interesting point. I am licensed in NJ and only have an auto license. I know nothing of what other states require; do you? Also brings up the point of legality in driving in other states. H'mm!!!
Hank

[Superchief]

Hank, Whatever your State requirement are, is good in other States. You can not legally possess two or more driver's licenses. In New York State, you need a "B" endorsement if your Motorhome is over 26,000 lbs. There has been previous posts about other States on this Forum before. I know Texas has a requirement, as do several other States. Craig


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[Superchief]

Hank, Here is a table (series of photos) about requirements by States... Craig


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[Superchief]

Hank, New York is a "R" endorsement, not a "B" endorsement - should have looked at my license - me bad!!! Craig


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[I-RV]

Thanks for the info.; Craig

Hank