It rained during our recent two-week trip to the east coast. A lot.
Prior to the trip, the air gauge would hold 90+ psi overnight. It would take a couple of days for the tanks to fully empty out. Air bags hold air for weeks (or longer, I guess, but we haven't stayed still longer than a few weeks.)
During the trip we used the wipers. A lot. I kind of grew accustomed to the quirky speed adjustments. I even got pretty good at getting them parked the first time I tried.
One bad note though - during the trip I noticed that the air gauge was going down faster. By morning we'd be down to 60 psi. Or maybe even down to 30 psi.
The last time this happened I found a fitting on the driver's wiper system that needed to be snugged up. Today I went out to check and see if there was another fitting that needed a little wrench action. What I found instead was that the passenger wiper motor was leaking out a small amount of air.
I aired up the bus to 120 psi. Of course, now more air was leaking out. Then I ran the passenger wiper a few cycles and parked it again. This time I didn't hear any air leaking.
Is it normal for the park position of these things to start leaking air? Is it difficult to re-seal the motor? Is it even worth the effort?
Or, is the leak not in the motor at all but in the hand control (switch)? I looked in the manual and see that there is a parking plunger in the hand control which has an o-ring. Possibly this is where the leak is?
Any advice from those who have rebuilt and/or repaired these things would be appreciated.
Not wanting to replace with electric right now. I know that option is out there, but I don't think the situation is anywhere near to the point I need to go down that route right now. The wipers work well, other than this issue. Eventually I may have to go electric, but if this air leak can be solved with an o-ring that's my preferred route.
Forget electric unless you cobble up something. Nobody offers any conversions for GMC's at any price. I replaced my wiper controls. Luke had them and not that costly. I also got kits and rebuilt the motors. After 35 years, o-rings and seals shrink and crack. The manual shows you how to rebuild them. Be careful of getting the indexing marks correct on reassembly. You need a spanner wrench to get the big nut off the main wiper shaft. They are reversible if you switch the valve body. Its the 4or5 inch tubular shaped piece attached to the main unit. Inside the valvebody is a shaft with o- rings. Later models utilized nylon or plastic and tend to crack around the threaded air line ports. Be careful with them. Older ones were diecast and more robust.
Even though your coach is in such great shape with low miles, you are seeing that some things are gonna need maintained.
Btw, have you ever changed your differential oil?
Thanks for the info. Maybe I will start with the wiper controls. Seems like the path of least resistance, and for now I am leaning towards the leaking at park being the fault of the control.
Luke/Bill replaced the differential seal last summer before I bought the bus. I'm assuming that the oil was changed at that time. I'll have to check the paperwork to confirm. Is this a known problem area?
As rare as the 4 1/8 rears are, I'd take good care of it.
Quote from: chessie4905 on October 03, 2018, 06:05:03 PM
As rare as the 4 1/8 rears are, I'd take good care of it.
I just pulled the invoice from what Luke & Bill did last summer. Apparently the pinion drive bearing seal was replaced, but I don't see any differential fluid on the invoice. From what I can tell this seal can be replaced without draining the differential, so there's no telling when the differential oil was last changed. I'm assuming that the original owner did some maintenance on the bus, as he owned a charter bus company and kept the bus there, but there's no was to know for certain.
When the bus was in his shop last week Bill did check the differential oil level, which was okay.
Other than knowing the oil level in the differential is okay, I know nothing about the age or quality of the oil. I'll have to add this to my list for the spring maintenance, probably along with repacking the wheel bearings at all four corners. We're not going to put that many miles on between now and then, so I'm guessing things will be okay for now. Book calls for 140 wt multi-purpose gear lubricant, which I assume is still the fluid of choice.
So, I got the new wiper control valves from US Coach today. The valves currently in the bus have one end port (air in), and two side ports (output and park).
The new valves have all three ports on the end of the valve. Apparently the end port valves are the replacement for the old valves and the side port valves are NLA.
The bus is plumbed with copper tubing with flare fittings. I'm going to assume that it will be very difficult to reconfigure the existing copper tubing to change over to the end ports without danger of crimping the tubing or otherwise causing problems.
I know that there are new-fangled ways to run air lines using a nylon/plastic tubing which is much easier to work with and much easier to bend around obstacles. Can someone point me to information about this? I'm going to need to connect it to the feed from the wiper air filter outlet and possibly to a few existing flare fittings, so I hope that there are ways to accomplish this without reinventing the wheel.
Thanks.
I changed mine over to dot nylon tubing and fittings. I got my tubing and fittings from McMaster Carr. Tubing is 1/4" and you reuse fittings. You can reuse nuts, just get new dot ferrules and reinforcement inserts from them also. Made it much easier to plumb in my pulse wiper control also, which works nicely btw. Just finished it today.
Quote from: chessie4905 on October 11, 2018, 04:32:17 PM
...you reuse fittings...
Flared fittings as well? Or are the fittings that look like flared fittings actually compression fittings?
Also looks like there are two sizes of tubing currently in place, but it's hard to tell for certain since some is covered with a braided wrap/cover. Are these tubing measurements OD or ID? Then I can check with calipers to see if it's all 1/4 or if there is some 3/8 mixed in.
The nuts on air line are longer to handle vibration they can be flared or compression those are not nuts you by from your local Ace Hardware.They are B/W (Bendix Westinghouse) nuts,flares,compression and the threads are different
Are these fittings a NAPA item or am I going to be ordering everything from the internet? Milwaukee has quite a wide range of supply houses, but I've never shopped for things like this. Something the truck parts counters would have?
Feeling a bit overwhelmed for some reason on this, mainly because I have no idea of how much or what kind of tubing I'll need or how many and what type of fittings I'll need. Probably won't know until I get the thing taken apart. It's been a rule I've followed for a while to not take things apart until I've secured all (or nearly all) of what will be needed to put it back together. Sounds like that might not be the case on this project.
https://www.mcmaster.com/air-brake-lines.
1/4 inch od. The connections are all compression fittings. You use New 1/4" ferrules and inserts in end of tubing to keep it from collapsing when you tighten the nut. Reuse the old nuts as they are dot. and threads are different from lowes or ace hdwe, etc. Just buy a 10 foot roll of dot 1/4 tubing, compatible dot 1/4 inch ferrules and inserts for 1/4 dot tubing. The Parker stores carry fittings and nuts,etc. Our local one didn't carry any tubing. I've also purchased the tubing from Ebay. Just make sure you are buying dot nylon tubing. The next size larger tubing is 3/8" which may attach to the air filter. If you have any 3 /8" in your system, just buy tubing, ferrules, and inserts for that size also.
Quote from: chessie4905 on October 11, 2018, 05:36:14 PM
https://www.mcmaster.com/air-brake-lines.
1/4 inch od. The connections are all compression fittings. You use New 1/4" ferrules and inserts in end of tubing to keep it from collapsing when you tighten the nut. Reuse the old nuts as they are dot. and threads are different from lowes or ace hdwe, etc. Just buy a 10 foot roll of dot 1/4 tubing, compatible dot 1/4 inch ferrules and inserts for 1/4 dot tubing. The Parker stores carry fittings and nuts,etc. Our local one didn't carry any tubing. I've also purchased the tubing from Ebay. Just make sure you are buying dot nylon tubing. The next size larger tubing is 3/8" which may attach to the air filter. If you have any 3 /8" in your system, just buy tubing, ferrules, and inserts for that size also.
Thank you - that does clear it up. All I need to have on hand is the tubing, ferrules, and inserts. I'll lay in a supply and try and get it done before the temps get any colder. (Seems like winter is in a hurry to get here this year.)
I'm going to take from this conversation that I was correct in assuming that it was pointless to try and reuse the old copper. That being said, I plan to replace from the air filter up to the valves and then to the wiper motors.
Everyone does different but I don't uses the plastic DOT lines close to a dash ,I have seen the stuff melt when a wire shorted out and you have to make long sweeps or it kinks ,mice love it,one thing it is cheap and easy to work
If the connections are all compression fittings, the I could just bend new copper to do this as well, correct? I've always had much better luck bending new using a bending spring than trying to re-work old lines.
If I decide to go with copper for all or some of the lines, is there a particular variety of copper that is used in these air lines? Something tells me that I can't just use the stuff sold at Home Depot if it's going into the air system.
NAPA sells the DOT copper so does the Truck Supply parts houses
Really Cliff??? Come on. I've seen copper melt in a fire also. BTW, at least nylon won't short out against a bare connection. Also copper work hardens the more you work it.
Oh, just set a dish of mouse snacks near dash so they won't chew the lines. Or....https://www.lowes.com/pd/TOMCAT-4-Count-Wooden-Mouse-Trap/50192375
Quote from: chessie4905 on October 11, 2018, 07:29:04 PM
Really Cliff??? Come on. I've seen copper melt in a fire also. BTW, at least nylon won't short out against a bare connection. Also copper work hardens the more you work it.
I am not talking about a fire,I had wire short out in the tunnel where the DOT nylon lines supplied my leveling jacks it was a hell of a mess.Like I said we all do it different I only use it where it is easy to replace and no wires around it
Quote from: chessie4905 on October 11, 2018, 04:32:17 PM
I changed mine over to dot nylon tubing and fittings. I got my tubing and fittings from McMaster Carr. Tubing is 1/4" and you reuse fittings. You can reuse nuts, just get new dot ferrules and reinforcement inserts from them also. Made it much easier to plumb in my pulse wiper control also, which works nicely btw. Just finished it today.
nylon hose uses an internal sleeve ferrule.
i'm sure the OP (and you) know this.
the common copper outer sealing ferule alone often blows out...
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=dot+compression+inserts&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=dot+air+line+reinforcement+sleeves
Cliff, were those leveling Jack lines air or oil?
Quote from: chessie4905 on October 12, 2018, 03:25:46 AM
Cliff, were those leveling Jack lines air or oil?
They were oil with the oil rated and 3500 lbs nylon hoses pretty standard on hydraulic levelers.LOL every time I weld,grind or cut around that stuff under a bus sure as the sun comes up a piece of slag ,sparks or spatter will burn a hole in it then I have to replace it
Teflon tape/pipe dope - yes or no?
Not talking about the compression fittings here - talking about the fittings that screw into the valves and wiper motors that use threaded ends to make the connection. In plumbing I'd use either Teflon tape or pipe dope. Not sure what the protocol is for DOT air lines so I'm asking.
Most shops don't use tape on anything I use the PTFE compound which is liquid Teflon you can buy a tube or a can at NAPA it's a Permatex product
That's what I use also. A can or tube lasts a long time, and can be used in household plumbing also. I still use teflon tape in some applications. Like air lines in shop, etc.
Not sure if your valve body is metal or plastic...be careful with any kind of thread sealant if its plastic..Ive seen those break when tightening the fitting, and youre buying a new valve when that happens...fyi...dont ask how I know this