Likely air leak locations

Topic: Likely air leak locations (Read 3300 times) previous topic - next topic

Re: Likely air leak locations

Reply #25 – March 05, 2019, 08:36:31 pm

From my limited knowledge of air systems, it is not recommended to open drain valves at full pressure. Maybe it is OK to do that once in a while, but should not be a regular thing as I understand it. This can erode the seat of the valve and make things worse. Some thing to consider. Have a great day ---- Fritz

Re: Likely air leak locations

Reply #26 – March 08, 2019, 12:11:45 pm

i found a leak in my parking brake switch and one that i chased forever was an air chamber diaphragm

Re: Likely air leak locations

Reply #27 – March 08, 2019, 01:28:08 pm

Ok, I found two major leaks and a few not so major leaks. I'm not sure exactly what I'm looking at but do have a couple pictures so maybe someone can help me out. Both of the low pressure switches connect under the brake pedal are steadily leaking. That's the not so major leak. One of the major leaks is coming from what appears to be an air pressure regulator and associated electronic control box located under our entryway stairs. Both the controller and regulator are leaking pretty severely. I'm not sure what it's regulating but I did notice that if it set on say 80 psi it will purge air until the tanks read 80 psi and then it stops purging. It still leaks around the body though. The second sever leak is coming from a valve body that is bolted to the (I'm assuming) the ecm for the throttle. It has an inlet and outlet controlled by two solenoids. It appears to be the solenoids that are leaking. I removed the assembly and Googled the number on the back with no luck. Does anyone know what these things are and maybe how they function?

Re: Likely air leak locations

Reply #28 – March 08, 2019, 01:30:42 pm

Forgot to add pictures, sorry.

Re: Likely air leak locations

Reply #29 – March 08, 2019, 02:32:16 pm

Let me see if I can help.

The pressure switches under the brake control valve might just need to be tightened up (the fittings). If not, then they can probably be replaced fairly easily. You would have to remove them and see if there is any ID number on them, then do a Google search for a suitable substitute.

The thing under the stairs is a control valve that directs the air pressure going to the step cylinders. The regulator reduces the coach system air to a lower value (60-80 psi) suitable for use in operating the cylinders. You can remove the whole control assembly and take it apart. Might be able to clean it up - possibly replace some O-rings, and return it to service. If it can't be repaired, then you can buy replacement units online. Again, helps to have a part number when you go hunting. There is some info in the threads linked below that might be helpful.

GV Entry Step Actuating Cylinder

GV (Unihome) Air Step Mod

The last one is gonna be tough. Parts for the old Bendix cruise control assembly are like hens teeth - rumored to exist, but virtually impossible to source. Again, if it is the solenoids leaking, it might be possible to solve that with O-rings. You have to take them apart and see what you find. Here is a reference manual for the Bendix unit. Will help you figure out how it works. Also, a "corrected" diagram of the cruise control system, showing the additional parts and lines used on our coaches to add the air throttle function.

Re: Likely air leak locations

Reply #30 – March 08, 2019, 04:06:55 pm

When working on the air system, especially if rebuilding valves, and when replacing O-rings, a good lube is essential. I recommend Super Lube.

https://www.homedepot.com/p/Super-Lube-3-oz-Tube-Silicone-Lubricating-Grease-with-Syncolon-PTFE-92003/202932697?MERCH=REC-_-PIPHorizontal2_rr-_-202932687-_-202932697-_-N

Re: Likely air leak locations

Reply #31 – March 08, 2019, 04:44:55 pm

An SOB here in the park has an extended warranty (aftermarket). The left rear of the coach is lower than the other three coners lately (airbags) so the owner took it to a dealership for warranty work. When he picked it up the next day they presented him with a bill for $900.00, told him the extended warranty only covered labor, not diagnosis and they had found nothing leaking.

Re: Likely air leak locations

Reply #32 – March 08, 2019, 05:17:23 pm

Quote from: Travelin' Man – March 08, 2019, 04:44:55 pm

When he picked it up the next day they presented him with a bill for $900.00, told him the extended warranty only covered labor, not diagnosis and they had found nothing leaking.

Wonder if they provided complimentary Super Lube when they "presented" him the bill.

Re: Likely air leak locations

Reply #33 – March 08, 2019, 05:46:05 pm

Ok, I did a little more investigating and what I found is that vent no. 5 is leaking when the step is down, the step cylinder around the polished rod is leaking when the step is up and the electronic end of the distribution block is leaking at all times. I am going to forgo the attempted repair of any of those issues and instead try to install an inline shutoff valve on the air inlet just before the pressure regulator. I will let everyone know if it works. It also appears that someone has done installed a toggle switch in the bay to control the up and down of the step from there. There is another one below the dash to the right of the steering column that also has something to do with the step, but it doesn't seem to do anything.

Re: Likely air leak locations

Reply #34 – March 08, 2019, 05:49:28 pm

Quote from: Chuck & Jeannie – March 08, 2019, 05:17:23 pm

Wonder if they provided complimentary Super Lube when they "presented" him the bill.

There is no lube provided in those type of situations!

Re: Likely air leak locations

Reply #35 – March 08, 2019, 08:08:44 pm

Tyler. I and a couple of others have done that idea of adding a solenoid valve to the valve body so when the step is either up or down depending on what you want you just flip a switch on dash and the air is terminated and no more air is lost. I found a great amount of air was bypassing the O ring in main cylinder for step cover and the cylinder could not be taken apart so I left it in and stop any loss of air while driving and this works good. In Beamalarm under Modifications you will see a write up of this and pics.. There is also one on how to wire in a switch to keep the step up when parked, simple wiring job.
JohnH

Re: Likely air leak locations

Reply #36 – March 10, 2019, 05:07:44 pm

One leak fixed! It may not be a glamorous fix but it is simple, reliable and effective! The best part is that there's no electronic wizardry involved and in my book I call that a double win! Sure it's not as convenient as a switch on the dash but I'm quite capable of bending down and turning a lever by hand. Now to try and figure out the solenoids in the back.

Re: Likely air leak locations

Reply #37 – March 10, 2019, 05:37:38 pm

One little suggestion: instead of teflon tape, the smart kids on this Forum recommend using pipe sealing paste when working on the air system. There is less likelihood of a small bit breaking loose and getting stuck in a valve seat somewhere downstream from your repair.

I've had good results with the product linked below - there are others. Available in most auto parts stores. One small tube will last for years.

Permatex® High Temperature Thread Sealant - Permatex

Re: Likely air leak locations

Reply #38 – March 10, 2019, 06:08:16 pm

We had bottles of that stuff laying around when I was building natural gas skids. I'll have to get some for the next project.

Re: Likely air leak locations

Reply #39 – March 10, 2019, 08:00:21 pm

It's been a little over 3 hours and we still have 40psi on the dash! We're making progress haha!

Re: Likely air leak locations

Reply #40 – March 10, 2019, 08:04:28 pm

It' the little things in life that make it so much fun

Larry

Re: Likely air leak locations

Reply #41 – March 10, 2019, 08:52:04 pm

Quote from: ohsonew – March 10, 2019, 08:04:28 pm

It' the little things in life that make it so much fun

It does feel good

Re: Likely air leak locations

Reply #42 – March 10, 2019, 09:05:34 pm

I removed the solenoid assembly again to have a go at it but I'm not sure how it comes apart and I don't want to break it trying to figure it out. I'm not too smart with this stuff, that's why I opted for a mechanical valve rather than an electric one on the door step, and if I break this assembly there's a good chance we'll be stuck here. It might be best to reinstall it and look for another one somewhere.

Re: Likely air leak locations

Reply #43 – March 10, 2019, 09:30:45 pm

Wish I could help with the solenoid assembly, but I have not tried to take ours apart. It is not obvious from your photos how it comes apart. Best not to break it, unless you have another one in hand. I am afraid that will be a very difficult part to find. I'll see if I can find you any help. Some guys at one of the Bluebird forums were pretty deep into working on these systems. I'll see if I can find some contact info for that group.

Re: Likely air leak locations

Reply #44 – March 10, 2019, 09:45:03 pm

Here's a link to the Wanderlodge Owners Group. Some of their coaches use the Bendix cruise system.

Right above where it says: Welcome to the Wanderlodge Owners Group" there is a search box. Put "bendix cruise control" in there and search. You'll get lots of hits to read through. Perhaps you will find something about a source for used solenoid assemblies? Worth a look.

Wanderlodge Owners Group - Powered by vBulletin

Re: Likely air leak locations

Reply #45 – March 10, 2019, 09:45:58 pm

Quote from: Chuck & Jeannie – March 10, 2019, 09:30:45 pm

Some guys at one of the Bluebird forums were pretty deep into working on these systems. I'll see if I can find some contact info for that group.

Thanks Chuck! I'm on the WOG site frequently just perusing the 'for sale' section as I have a real soft spot in my heart for the Wanderlodge. I'll sign up for an account and ask around as well. It's really cool how these things cross brand lines, like the Newell guys with our air conditioner problem.

Re: Likely air leak locations

Reply #46 – March 10, 2019, 09:52:55 pm

Found a old post that may help, if you do want to disassemble the solenoids. Check this out (Reply #329):

What did you do to your coach today VII

RVtinker (Mike & Lilli) is active on the Forum - was here today. Might send him a PM if you need help chasing air leaks!

Re: Likely air leak locations

Reply #47 – March 10, 2019, 10:17:29 pm

Dang Chuck, you're really on it!

A was able to find a part number which is 065030 according to some old bendix parts catalog. I'll check out that link and see what I can do!

Re: Likely air leak locations

Reply #48 – March 10, 2019, 10:29:30 pm

Followed rvtinker's instructions and the solenoids came off easy as can be!

I am feeling 100x better than I was a few minutes ago! I'll get some new o-rings tomorrow and see if that solves the problem! Thanks so much to everyone for your help!

Re: Likely air leak locations

Reply #49 – March 10, 2019, 10:31:54 pm

Don't forget the Super Lube!

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