We are stuck in Ocean Springs, MS with no brakes and no pressure. I read about an air governor or pump. I am not a mechanic, but just looking for some help. '95 U300 SE. Thank you.
Hang on. here's your specs:
if you have no air pressure, your brakes are on.
first thing to check is the air governor. a $20.00 item, and an easy fix.
good luck. lots of people carry a spare governor
Update: I tried loosing the nut on the bendix air governor and then turned bolt or screw 360 degrees counterclockwise and then back clockwise. Didn't help. When we shut the engine off, you can hear air leaking. It seems to be coming from the Bendix, but not sure. Would that seem like it's the problem? Thank you for the quick responses!
Air pump belt intact and compressor spinning? Can you hear air leaking anywhere?
Try to find your D2 valve, most likely on compressor smack it with something metal like a cresent wrench, there's also an adjustment screw under the cone shape plastic cover that you can turn in and out to try to unstick it. See photo
A bit more information would help us narrow down the possible trouble area.
Were you driving when you lost air pressure, or is the coach parked somewhere and would not build air pressure when you started engine?
If driving, did you lose air pressure in just one tank, or both tanks simultaneously?
If parked in one spot for several days, have you checked the water drain valves for all air tanks to be sure they are closed?
Here is some info on the D2 governor:
http://www.plazafleetparts.com/uploads/2/1/9/0/2190100/d-2_governor_maintenance.pdf
Haldex D2 Governor Service Data (http://beamalarm.com/Documents/haldex_d2_governor_service_data.html)
We just returned from NAC with after a recent brake issue. Best way to describe my concern was: "After building air at startup, Coach lost air while 'feathering' brakes to jockey coach out of home base. Builds air back, seems drivable."
I lost enough air (<70#) to be a real concern after startup. MOT replaced my D-2 gov and the step slide valve. Last Friday. The real problem was my brake pod(s) according to Keith. A few days later, MOT hadn't heard from Meritor. FT had no workaround, so I called Berndt. (He owns World Line Auto on Main.) His guys "upgraded" my obsolete pods. It took a couple of tries, in that the OEM Pod's exhaust matched the new parts intake...so backwards—do overs.
NAC is the perfect place to have a problem with your coach. Between Keith, Braxton and Berndt and a few others, they could give most drivers a way back on the road. The age of these rigs require some work-arounds and I believe between our Forum and some experienced folks exists a real blessing!
Paul, is the "pod" you are referring to the brake can or actuator?
Here's where you are, in the white area, closest to Biloxi. Perchance there's a forum member close?
So... update: Replaced governor, bypassed dryer and it worked up to 125 psi. Ordered a filter for the dryer and replaced the old one. cleaned out the valve on the bottom of the dryer after that didn't work. Looks like the dryer is bad. Any idea on what dryer I should get? U300 SE '95 M11 Cummins. Thank you!
My suggestion is to identify the dryer and get a FACTORY (as in the factory that made it) REMAN air dryer. All valves as well as filters will be new.
Should be a direct bolt-in.
If dryer is to be replaced, simply remove the whole dryer assembly and carry into any local NAPA parts store. Tell them you want (as Brett advised) a factory remanufactured unit. If you are lucky and they have one in stock, remove it from the box and compare it to your old dryer. Check to make sure they both hook up in the same way, and see if you need to transfer any fittings from old unit to new (rebuilt) unit. If the store does not have one in stock, but can order it, HOLD ON to your old dryer until the new one arrives, then compare them. The store will add a core charge to price if they have to order it, but you'll get it back when you turn in the old one.
A episode like the OP had is a great reason why Brett told me to replace ours after six years, PERIOD! ^.^d
Loosen the fittings before you unbolt it
Take pics before you unbolt it. Ask me how I know ?
While on the dryer subject,what is the rule of thumb time frame after you change yours and start from zero?
Three years for service/replace. If you only operate in the desert SW, maybe a little longer.
My suggestion is alternate between "factory reman" and "rebuild with new filters". And, if paying labor, the factory reman is a good "always" answer.
Again, that is factory as in the factory that made the air dryer. The remans have not just new filters, but new valves, heater, etc.
Probably once a year, I inspect a coach that has had a desiccant failure. REALLY easy to identify-- when you open the wet tank drain, white powder comes out. That can lead to a "many coach bucks" repair, as it can clog all the components of the suspension and brake system.
Not servicing/replacing the air dryer IMO is similar to never changing the engine oil. Really poor long-term decision!
I don't know the "official" answer, but I would think it is not so much
time (or mileage) as it is
engine hours.
A coach sitting parked without engine running is not putting anything through the dryer, so degradation should be minimal.
A coach with engine running, whether parked or moving, puts (some) air through the dryer and so components will wear out at some (?) rate.
When Brett told Mike "6 years" he may have been referring to the max "shelf" life of the desiccant cartridge, whether it is being used or not.
Yup........
The newer cartridge style is an easy annual spin on replacement.
I have this one ;New Air Dryer Assembly - Replaces Meritor Wabco System Saver 1200Series... (https://www.ebay.com/itm/New-Air-Dryer-Assembly-Replaces-Meritor-Wabco-System-Saver-1200Series-R955205-/282513506036?hash=item41c71dfef4)
I recommend taking this unit to NAPA and matching up the cartridge before you install it . Some come with no numbers on the cartridge at all .
I had to drill a hole or 2 and swap the fittings. These seem to be the standard deal for replacements around my area. Lots of trucks running in the wet FL air.
My factory manual says 18 months replacement cycle. I agree it is overkill but the consequences of waiting too long can be catastrophic.
18 month service interval is probably a very good recommendation for OTR trucks who do many times the miles we do and use a lot more air than we do.
Mike do you have part Numbers for the newer cartridge style and will it fit my coach a GV320 2000 or do I have to have the housing replaced? (sorry not too knowledgeable about this stuff)
Tommy,
Call the company that made your air dryer and ask for a supercession that has spin on filters. Yes, you could go with another brand, but connecting to the original plumbing may be an issue.
I was wondering if ours has spin-ons or could be modified? Sure be handy! ^.^d BTW, I had to look up that $5.00 word!
Mike,
From my records (ASSUMING it has not been changed with another brand/model): Already upgraded from Bendix AD-4 to Bendix AD-IP.
http://www.anythingtruck.com/instructions/060-AD-IPServiceDataSheet.pdf
One large bolt (called "cartridge bolt" in the above PDF) from bottom secures filter. EASY.
So, I can just order the filter and not screw around removing the whole assembly? Wowsers! ^.^d
Mike ,with all due respect while sitting in the Desert you could be reading all about them and learning as you should know about this item and the miriad of other things that are important. That is what I do and keep going online for issues/fixes that are not in those FT books. I take out info from various places that COULD impact me on the road and start my own diary so I hopefully can make a judgement and fix while out O the road.
Just my 3 cents worth ( converted to canadian )
JohnH
Hey all! Thank you so much for all your help! It was not fun being stuck in an unwanted place in Mississippi with no brakes/air! It turned out that the governor and dryer needed to be replaced. We are now in Lynn Haven, FL and everything is working properly. Again, thank you for all your help and quick responses. I've learned so much about the air system and I'm not mechanical at all... I guess I can learn to be. Blessings!
Josh, Glad you are back in business and thanks for posting your follow-up.