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Topic: Working On My Six Pack (Read 10753 times) previous topic - next topic

Re: Working On My Six Pack

Reply #20 –
Good Job!

 Great write-up and documentation. Look forward to the outcome...............

Re: Working On My Six Pack

Reply #22 –
@craneman:

Good find!  That is where I put in my order this afternoon!  On the page you linked, click the top left icon (-000 Series).  On the following page, scroll down to part # SN70019 - that's the one you want.  I ordered 24 (enough to do all 12 valves on our coach, twice), and it came to $11.17 with postage included.

Direct link:  019 Buna-N Square O-rings - Tetraseals [SN70019] : The O-Ring Store LLC, We...

Re: Working On My Six Pack

Reply #23 –
Just ordered mine.
Thanks for the link.

Re: Working On My Six Pack

Reply #24 –
Good find guys, but looking at the type of material would not the Viton be a better choice as it is good for synthetic oil too??
JohnH

Re: Working On My Six Pack

Reply #25 –
Quote from: John Haygarth –
Good find guys, but looking at the type of material would not the Viton be a better choice as it is good for synthetic oil too??
JohnH
The site lists the Buena as best for petroleum oils which is what I am using for my hydraulics. I have Transynd in the tranny but using Delo for the hydraulic system.

Re: Working On My Six Pack

Reply #26 –
Am I missing something? These "O" rings are internal to the Six pack, right? In which case, their job is to seal clean, dry (ideally) air. Perhaps I missed a transition to seals in the hydraulic system... have to go back and read through the thread again.
Don
Quote from: craneman –
The site lists the Buena as best for petroleum oils which is what I am using for my hydraulics. I have Transynd in the tranny but using Delo for the hydraulic system.

Re: Working On My Six Pack

Reply #27 –
Quote from: Don & Tys (AKA acousticart) –
Am I missing something? These "O" rings are internal to the Six pack, right? In which case, their job is to seal clean, dry (ideally) air. Perhaps I missed a transition to seals in the hydraulic system... have to go back and read through the thread again.
Don
You didn't miss anything I am still focused on my hydraulic fan motor and slipped up. I hope I don't have any oil of any kind other than the lube I put on the seals. On my cranes I do get some engine oil in the air system but that is because the old type compressors bleed oil and I have to drain the tanks periodically.

Re: Working On My Six Pack

Reply #28 –
Quote from: Don & Tys (AKA acousticart) –
Am I missing something?
No, we're still on track - talking only (please) about the air system.  I assumed JohnH's comment had to do with the type of O-ring lube, which is the only "oil" these seals should ever see.  Since Buna-N is one of the most common O-ring materials, I am sure there are a number of excellent installation/lubrication products that will be compatible with these seals.

Re: Working On My Six Pack

Reply #29 –
Quote from: Chuck & Jeannie –
I assumed JohnH's comment had to do with the type of O-ring lube, which is the only "oil" these seals should ever see.

So are using any type of O-ring lube? In the past I've used Vaseline & lately started using silicone grease. Probably not the best stuff to use. :(

see ya
ken 

Re: Working On My Six Pack

Reply #30 –
Ken,

I'm going to town today - plan to stop by the local O-ring Emporium, and pick their minds.  I live in OILFIELD country, and every single piece of equipment used in the Patch has a multitude of rubber sealing devices.  I am sure they will be able to recommend a good installation lube for our rather simple application.

PS: When I worked for Schlumberger, we routinely worked with flow lines, manifolds and valves which were rated at 10,000 PSIG working pressure.  Every single piece was fitted with O-rings.  You should see what happens when you remove a rubber O-ring from a joint of tubing that has been exposed to high gas pressures.  Due to gas permeation, it swells up to about 10 times the normal size - looks like a big rubber Donut!

Re: Working On My Six Pack

Reply #31 –
Still waiting on parts, so, another dissertation...

One of my biggest concerns in doing this project is the worn sealing surface on the "plungers".  (See photos below)  I have been careful, as I do my cleaning, to keep all the parts of each individual valve together.  However, when you disassemble the valves to replace the inner seal, it is impossible to avoid disturbing the relationship between the plunger sealing surface and the valve seat.  If the seat and the plunger are not perfectly concentric (they are not), then it is possible they may not seal properly when the valve is reassembled.

Plan "A" is to hope for the best (Murphy was a optimist).  I will install the rebuilt six pack in the coach, and give it a try.  If it holds air, all is good.  If it leaks, I'll remove it (again) and go to plan "B": Replace the plungers.

Plan "B".  The problem we Foretravel owners have with these HWH valves is not unique.  Other SOB's use the same valves.  Search the Net and you will find numerous references to these valves, and the attendant problems.  HWH will not sell individual replacement parts for these valves, other than O-rings.  You must buy a complete valve assembly (expensive), even if all you need is a new plunger.  One of our own, Jim McNeece, several years ago posted a alternative source for a possible replacement plunger.  I have just touched base (PM) with him, to get a update on his experience.  I will relay his reply, or perhaps he will add a note to this thread.  Jim's old post:

Possible HWH Solenoid Replacement Plungers

Re: Working On My Six Pack

Reply #32 –
 Chuck, I was referring to the rings being lubricated by a syn' grease, not moving syn' oil as I was aware of the valves job in service. Got to commend you on this job and documentation too as it really helps all of us try and save money and learn more about parts of our coach's. Mine do not leak (as far as I know) but it would be a nice little project to do one nice day in the pit, after others are done I have listed.
JohnH

Re: Working On My Six Pack

Reply #33 –
SIX PACK REBUILD - COMPLETE PARTS LIST

Reminder:  Everything I list here pertains to the FRONT six pack manifold on our '93 model coach, with the HWH 600 Series leveling system.  It is up to you to verify if these items are the same on your coach.  Newer models might differ, but I think the HWH hardware is pretty consistent over the model years.

O-RINGS

All the O-rings I have encountered are standard AS568 sizes.  These are readily available online, and possibly from local vendors.  Online prices change, sometimes daily.  I will link where I purchased my O-rings, but you should shop around for the best current price.

Air Inlet Check Valve (2 in front manifold):  AS568-10
-010 N70 Buna-N Nitrile 70 O-ring [B70010] : The O-Ring Store LLC, We make...

Air Inlet Check Valve Retaining Plug (2 in front manifold):  AS568-13
-013 N70 Buna-N Nitrile 70 O-ring [B70013] : The O-Ring Store LLC, We make...

Between the brass valve and the aluminum manifold (small O-ring):  AS568-15
-015 N70 Buna-N Nitrile 70 O-ring [B70015] : The O-Ring Store LLC, We make...

Between the brass valve and the aluminum manifold (large O-ring):  AS568-28
-028 N70 Buna-N Nitrile 70 O-ring [B70028] : The O-Ring Store LLC, We make...

Brass valve internal seal, under the stainless armature tube (square O-ring):  AS568-19
019 Buna-N Square O-rings - Tetraseals [SN70019] : The O-Ring Store LLC, We...

PRESSURE SWITCH

On the front six pack, there are 2 pressure switches, 10 PSI, Normally Closed:  Originally made by Honeywell, part # 76578-10 NC
Stewart Warner-Stewart Warner - Hobbs Pressure Switch 10 psi Normally Closed...

AIR CONNECTIONS

Our front manifold was originally fitted with compression-type air connections.  With my rebuild, I have elected to change over to more modern Parker Prestomatic "push to fit" air connections.  These are now quite common on over-the-road trucks, are fully DOT approved for all air brake systems, and have a max pressure rating of 250 PSI.  They are reusable, which will be handy if I ever need to remove this manifold again.  You just push in on the tube and the retaining ring, and the tube pulls right out.  Push the tube back into the fitting, and it is ready to go again.  EASY!

There are six air hose connectors, size 3/8" tube X 1/8" NPT
Parker Male Connector, 3/8 x 1/8 In 68PMT-6-2 | Zoro.com

There is one air hose connector, size 3/8" tube X 1/4" NPT (the air inlet fitting)
Parker Male Connector, 3/8 x 1/4In 68PMT-6-4 | Zoro.com

You will also need one (or two) brass 1/8" NPT male X 1/8" NPT female 45 degree fittings.  This is necessary because the mounting holes for the 2 pressure gauges are too close together to screw them straight in.  One gauge must be offset to the side slightly.  You can buy this fitting online (Amazon or eBay), or at your local NAPA store.  I am planning on using 2 of these 45's, one for each gauge.  This will allow easier access to the exhaust ports on the manifold, for the purpose of keeping them clean.  See photos below:

Re: Working On My Six Pack

Reply #34 –
Additional photos of parts listed above.  The "cigar cutter" is a cool little Parker tool for trimming the end of the air hose.  It insures a clean, straight end cut, without squeezing or deforming the tube.  A necessity when using the Prestomatic connectors.

PTC-001 Parker Tube Cutter | MRO Stop - Industrial Supply + Technology

Re: Working On My Six Pack

Reply #35 –
Quote from: kenhat –
So are you using any type of O-ring lube?
@kenhat
You asked about lube.  As promised, yesterday I stopped at the local O-ring store.  They had both of the small O-rings needed for the check valves in stock, so I asked for 5 of each.  The nice lady behind the counter tossed them in a plastic bag, and also threw in a 1 ml "sample" tube of Super Lube.  She said that's what they recommend for all gasket & O-ring installations.  When I got out my wallet, she said "Don't worry about it - just have a nice day".  Can't beat that kind of service!

When I got home, I discovered Super Lube is available at all the Big Box stores, Lowe's, Home Depot, etc.  Very highly recommended.  Next time I go to town, I'll get a bigger tube.  Sounds like great stuff - pretty much does everything...except cure hemorrhoids.  Too bad about that...  :(

Super Lube 21030 Synthetic Grease (NLGI 2), 3 oz Tube: Science Lab Cleaning...
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Working On My Six Pack

Reply #36 –
Ha! I have a tube of Super Lube in my bicycle tool box! It's probably 10 or 15 years old. That stuff has been around for a while. I just went out and checked and yep I still have about a half a 3oz tube. :)

see ya
ken

Re: Working On My Six Pack

Reply #37 –
Awesome write up on a topic of interest to the vast majority of Foretravel owners with a mindset to "do-it-yourself"! ^.^d
Don

Re: Working On My Six Pack

Reply #38 –
Some may question my replacing the (front manifold) pressure switches, since they are expensive.  Well, what do they do?  From my reading, it appears they mainly function as a safety device, to prevent the coach from being severely "twisted" during auto-leveling and manual leveling operations.

"The air bag pressure switches are used as air bag low air pressure warning switches when the system is in the travel mode. When the system is in the leveling mode, the air bag pressure switches are used to protect the vehicle from excessive twisting during the leveling procedure, specifically when the system is doing a lower procedure."

If you have ever traversed a steep driveway entrance/exit, especially at a angle, and heard your windshield panels creaking and groaning in the frames, then you know about "frame twist".  Something to be avoided, especially in older GV models.  If the pressure switches can help prevent popping a windshield out of place, then I want them in tip-top condition.  Plus, there was no way I was putting my shiny clean manifold back together with grimy, cruddy 20+ year-old switches - aesthetics alone demanded they be replaced!

Footnote: Above quote came from Lesson 10, "Air Suspensions & HWH"...part of the excellent HWH Online Technical School.  If you really want to learn about and understand your air suspension system, then you need to study the applicable training modules on this page:

HWH Online Technical School

Re: Working On My Six Pack

Reply #39 –
One Thing Leads To Another:

After being introduced to the concept of a "square" O-ring (the inner seal on the air valve), I got to wondering how these would work in the other two O-ring positions - between the brass valve body and the aluminum manifold.  Hmmm...  Looking at the O-ring grooves (also called "glands") on the underside of the valve body, it appears they are cut in a "square" shape, with clearly defined "corners" in the bottom.  Seems like a square shaped O-ring would drop right in, since it is exactly the same size as the corresponding conventional round ring.  The TetraSeal literature from Parker says:  "In most static applications, it is a direct replacement for an O-ring and generally will perform a high pressure gasketing function as well as or better than an O-ring."

Since I know the sealing surfaces on my aluminum manifold are not perfect - I had to clean up several areas of chemical etching, and some fairly deep transverse scratches - I am thinking the increased contact area of the TetraSeals might be advantageous.  At any rate, I have ordered a set of the square rings in -15 and -28 sizes.  When they arrive (probably Tuesday), I will try fitting them in the grooves, and see how they look...

Stand by for (MORE) photos and my (not) "expert" opinion.