blakeloke Report post Posted March 13, 2016 During cooler weather I sometimes can hear a hissing coming from the engine bay at the air governor. I'm thinking, although I have not pinpointed the exact location yet, that the governor piston is not reseating properly. I still need to crawl under there and do a thorough inspection of hoses but before I do anything I wanted to appeal to you all for advice on what to look for and what to be careful of. I've read a post that dates back to 2013 or so (believe it may have been Tom that started it) and thought it wise to ask the experts first. If you remember, we had an issue with losing air pressure late last year and barely avoided getting stuck in I-40 in New Mexico. Since then we had the air dryer/filter replaced and had a Monaco authorized shop here in Conroe TX replace our old leveling system block (old, discontinued Firestone Intellitrak made in Dublin). Our air system has plagued us since the year we bought the coach which was back in 2005. So, our coach now levels, dumps and lifts perfectly now. And, it stays level......but, sometimes we lose braking air pressure. Combination of that and the hissing leads me to believe it may be the governor. The compressor seams to be fine as it builds pressure quickly (unless it's cold). I already have the new governor and plan to do the work myself. Thanks a bunch Blake Share this post Link to post Share on other sites
wolfe10 Report post Posted March 13, 2016 Blake, Yes the governor is easy to replace. It will be between your on-engine air compressor and the air dryer. Follow the air lines to locate. Have some thread sealant handy for changing out the fittings. I like Rectorseal #5. Share this post Link to post Share on other sites
blakeloke Report post Posted March 13, 2016 Thanks Brett.....should I pump the brakes and dump all air before I start? Share this post Link to post Share on other sites
wolfe10 Report post Posted March 13, 2016 Thanks Brett.....should I pump the brakes and dump all air before I start? A good idea whenever you are working on the air system. Share this post Link to post Share on other sites
jleamont Report post Posted March 13, 2016 Blake, on our coach it's located remotely (not mounted directly on the compressor) when I open the rear bay doors it's on the right side just next to the engine under my air filter mounted to the chassis not the engine. I actually carry a spare with me. The Monaco products seem to be similar with regards to their engine compartment layout. Share this post Link to post Share on other sites
Walt2137 Report post Posted March 19, 2016 Blake part # is Bendix 275491 , Midland KN18530 and CW to lower pressure CCW to raise. Walt Share this post Link to post Share on other sites
Walt2137 Report post Posted March 19, 2016 Be sure to mark or tag the lines before removing, don't ask how I know this. Walt Share this post Link to post Share on other sites
blakeloke Report post Posted March 21, 2016 Thanks for the help guys! Brett.......this looks to be a simple swap out.....think I will tackle it sometime this week. Joe.....our governor is located on the compressor. Bad thing is that the plastic air lines rub against the frame rails. They don't look bad now but I think I may cushion them with rubber hose or something similar. Walt.....thanks for the part number.......noted on labeling the hoses! Blake Share this post Link to post Share on other sites
jleamont Report post Posted March 21, 2016 Blake, do yourself a favor and go to a local truck parts store to purchase (remove and take with you). Monaco wanted $65.00 I bought the same one from Napa for $18.00. Share this post Link to post Share on other sites
manholt Report post Posted March 22, 2016 Joe. Call me dumb, but what is Monaco wanted? Share this post Link to post Share on other sites
blakeloke Report post Posted March 22, 2016 Carl, I believe Joe is saying that Monaco charges $65.00 for the air governor that he paid $18.00 for. Blake Share this post Link to post Share on other sites
jleamont Report post Posted March 22, 2016 Carl, I believe Joe is saying that Monaco charges $65.00 for the air governor that he paid $18.00 for. Blake YUP, exactly Share this post Link to post Share on other sites
blakeloke Report post Posted March 29, 2016 Update: Guys....really appreciate the help. I swapped out the governor on the compressor today. PSI built up to 130 and held at 120. There still is a bleed/leak somewhere albeit slow, but the topping compressor comes on as designed and shuts off at 120 PSI. Joe's recommendation to go to NAPA was awesome......$17.99 included the set screws and gasket. My skinny rear barely fit to change this out and highly doubt that Carl and his 6'8" body could fit in this little space. Most of you have been able to work through these issues rather quickly but I haven't until retiring since I've been up in Moon Township PA for the past 4 years and other global spots previous to that. Your knowledge is invaluable! Blake Share this post Link to post Share on other sites
jleamont Report post Posted March 29, 2016 Blake, glad to hear you are all fixed up. Now on to the air leaks. I had one that frustrated me, couldn't seem to locate it, next to my generator on the drivers side is the port for a tow truck to connect into. I was exhausting air from that port. On the front tank is a one way check valve that was not fully seated, I took the simple approach and installed a 1/4" ball valve behind the port and shut it off . I noticed mud bugs had been in the fitting, while there I replaced the fitting and zip tied the correct mating connector off of it just in case I ever needed a tow. Also, if you have an air line connection else where for airing up your tires, check that, mine was also leaking. On our coach it is located next to my propane tank 1st bay behind the steer axle. Lastly I had 3 of the 4 air tank drains leaking, very small air leaks. I replaced all of the ball valves that were brass and plastic with all brass valves with a Teflon seal. That will keep you busy on a weekend . Just remember to place jack stands under the coach if you have to crawl under it. To my surprise when I drained the air tanks the suspension stayed inflated. Share this post Link to post Share on other sites
blakeloke Report post Posted March 29, 2016 Joe, Thanks for the tips. Was under the coach spraying soap yesterday to see if I could detect the leak. Hadn't thought of looking at the fittings for airing tires and tow. Funny, I had to replace the wiper arm on the drivers side yesterday also and had the generator slide pushed out. I looked right at the quick connect and it didn't dawn on me to spray that and the other fittings. I'll tackle that today or next! Will need to run by Northern Tool to get a heavier set of jack stands first (durn....my second most favorite store beside Tractor Supply!). Blake Share this post Link to post Share on other sites
w5txxt5w Report post Posted April 15, 2016 This past summer had a hose from governor to drier that also rubbed on frame develop a leak. Fix or shield! This was a metal braided hose about 2-3 feet in length. Finding such a hose in middle of nowhere is a challenge. Fortunately near Vernal,UT in oil patch area and found a company who made a new hose including proper fittings etc. Looked a several OTH service facilities and no joy. Young son found the builder on internet ; >). Cost $44 and I felt like I has robbed the bank! Share this post Link to post Share on other sites
rsbilledwards Report post Posted April 15, 2016 Oh boy this great, I have some questions too, directly related. On my Panther the pump is a Bendix 550 and the governor is mounted on the outside front corner. From Cat the governor is not 65 bucks but more. Is the pump you are working on a Bendix, is it the same series? Yes mine is adjustable yet it only runs at 90 psi but apparently I'm drivin a dinosaur compared to some...tongue in cheek... but it is Porsche fast compared to some. ha. In the middle of no where there is usually a NAPA store and most make hoses, easy if you have one to copy. I too have a bunch of leaks to chase down, several I have found directly on top of the air bag mounts. Thanks Bill Share this post Link to post Share on other sites
blakeloke Report post Posted April 15, 2016 Bill, I'll check the governor manufacturer tomorrow. Haldex comes to mind but I'm not sure. My engine is a Cummins ISL and the governor is mounted directly to the compressor. Long story short, I'm still chasing a leak, or leaks somewhere. Fortunately the coach stays level now (Firestone leveling manifold - wasn't cheap) so the leak is isolated to the main air system. I've tested the valves and fittings that Joe mentions above and they appear to be okay. Also soaped the fittings around the front air receiver. No luck yet. Next, I'll start tracing individual lines from the dryer and downstream. Might be able to do this in the next day or two.....if not....I'm confident we'll be okay on the road as pressure holds steady at 120 psi when the engine is running. We have plans to be in Talledaga for the races so I may just have to live with it for that trip! Blake Share this post Link to post Share on other sites
jleamont Report post Posted April 15, 2016 Blake how old is your dryer? Share this post Link to post Share on other sites
dickandlois Report post Posted April 15, 2016 12 hours ago, w5txxt5w said: This past summer had a hose from governor to drier that also rubbed on frame develop a leak. Fix or shield! This was a metal braided hose about 2-3 feet in length. Finding such a hose in middle of nowhere is a challenge. Fortunately near Vernal,UT in oil patch area and found a company who made a new hose including proper fittings etc. Looked a several OTH service facilities and no joy. Young son found the builder on internet ; >). Cost $44 and I felt like I has robbed the bank! Bob, I just had to have the line replaced between the compressor and the Air dryer in February. The leak was enough to slow down the air up time. This happened after replacing all the air ride bags about a year ago. Thinking the line was weak or had a slow leak in it and with the new parts and any related leaks repaired, the supply line from the compressor could not hold up with a steady 120 to 125 lbs. of air pressure. Think it is a good thing this portion of air line is covered with a stainless steel braid. With all the road fodd !! Rich. Share this post Link to post Share on other sites
blakeloke Report post Posted April 15, 2016 Joe, The air dryer was replaced in January. Share this post Link to post Share on other sites
jleamont Report post Posted April 15, 2016 24 minutes ago, blakeloke said: Joe, The air dryer was replaced in January. Blake good! Often overlooked on an RV. Rich, that line is on my to do list, I do not like the way it looks. I have to measure it first and call Monaco/Allied for a replacement, they used two different lengths on my coach depending where the dryer was mounted but Allied has no more information other than that, so I have to measure it to be sure. Share this post Link to post Share on other sites
rsbilledwards Report post Posted April 15, 2016 It is not necessary to go to Monaco/Allied for the line. Remove it and take to Napa or your friendly CAT dealer and they can make it for you often on the spot. I say CAT only because they are an example. I suspect the local Cummins folks can do the same and for less than you know who. Blake, what manufacturer is you air pump? What size is the dryer and who made it? My coach does not have a drier and I want to install one. Bill Share this post Link to post Share on other sites
jleamont Report post Posted April 15, 2016 Didn't know a dealer could make a braided SS hose, I know my local CAT/NAVISTAR Dealer cannot, they can only make the rubber hoses to supply a brake chamber. I will have to ask around. To install a dryer I would call CAT tech support and ask them what pairs with your engine/turbo etc, give them your serial number and application, they will lead you in the right direction. I know there are many variances so you want to get the correct one. I think that is a great idea to retrofit one into your coach. Share this post Link to post Share on other sites
kaypsmith Report post Posted April 15, 2016 I think Carl is what Monoco Wanted!!!!! Share this post Link to post Share on other sites
