Cranked up to head home this morning and air pressure pegged at 65psi. Can't get going with that. Have a governer on hand but don't know where it is located on the coach, 2001 u295. Governor sound like the problem? Help locating would be appreciated.
On the engine air compressor on passenger side. Two bolts. Easy.
Watch on You Tube
See the link below for info on what governor (D2) looks like and how to adjust the activation pressure. Sometimes a stuck D2 can be coaxed into operation by turning the adjustment screw in or out a little. But best solution is to simply replace with a new or rebuilt unit. Available at most any NAPA store, and also most truck parts supply stores.
Owners should always keep one in spare parts box for future use, so good job on being prepared! ^.^d
http://www.plazafleetparts.com/uploads/2/1/9/0/2190100/d-2_governor_maintenance.pdf
Anyone have part number for NAPA D2 for ISM 450?
: https://www.napaonline.com/en/p/MBI275491RX reman $19
Amazon.com: D2 Truck Air Governor Bendix Midland Freightliner: Automotive (https://www.amazon.com/Truck-Governor-Bendix-Midland-Freightliner/dp/B005458FYY/ref=pd_rhf_dp_s_vtp_ses_clicks_nonshared_1_1/145-6664226-5182068?_encoding=UTF8&pd_rd_i=B005458FYY&pd_rd_r=23bd452d-7c83-4b94-a2ad-4d9a2b173306&pd_rd_w=Izpzo&pd_rd_wg=YAgxK&pf_rd_p=930d18c8-b847-4ad8-a160-854f3ef05c26&pf_rd_r=602YK0S3HPQ1WQXHFP5H&psc=1&refRID=602YK0S3HPQ1WQXHFP5H) $19
Amazon Prime Amazon.com: Air Control Governor, cross to Bendix P/N 275491 or Midland P/N... (https://www.amazon.com/Control-Governor-Bendix-275491-Midland/dp/B071P24RPX/ref=pd_sbs_263_t_0/145-6664226-5182068?_encoding=UTF8&pd_rd_i=B071P24RPX&pd_rd_r=87e7b8c7-3f73-401f-bbff-f3a86bcdcb64&pd_rd_w=KKAwX&pd_rd_wg=MIsUp&pf_rd_p=5cfcfe89-300f-47d2-b1ad-a4e27203a02a&pf_rd_r=J6HGX8HTCCHDH3T2JE7X&psc=1&refRID=J6HGX8HTCCHDH3T2JE7X) $17
Amazon.com: Bendix 275707N D-2 Governor: Automotive (https://www.amazon.com/Bendix-275707N-D-2-Governor/dp/B0056ZYJBA) new $54
AFAIK, all new and rebuilt D2s are physically the same as far as ports and mounting points. They might vary somewhat in external appearance (especially the "imported" ones). The main difference is the "activation point" that is set by the manufacturer. Some are set higher - some are set lower. Almost all of the ones currently being sold can be adjusted to your taste after installation.
So what I'm saying is: buy whichever one sounds best to you!
Got it changed. Started up. We'll know in a few.
Pressuring up but very slow. Fearing something else. Looks like it's going to peg at 65psi again. Two red alarm lights still lit on dash. Suggestions?
Actually stopped at 55psi. Might have been that before and I misread.
Need more info. Where are you located? Are you dealing with below freezing temps?
Did the coach act completely normal last time it was driven? How long ago was that?
Are all the air tank water drain valves completely closed?
Next thing you might check is the air dryer. If you can safely reach it with your hand (while engine is running), see if air pressure is being constantly released from the bottom exhaust valve (purge valve).
More ideas in this thread:
Getting pressure high enough to drive? (https://www.foreforums.com/index.php?topic=38335)
Dude,fill out the signature with as much coach info as you can so we know what you have.
While it could be a number of things, I would start by looking for a massive air leak. Check air dryer purge valve (bottom of air dryer, listen for air leak immediately after shutting off engine, check hoses from compressor to air dryer.
Seem to be fixed. Had hoses reversed. Do it every time!!!
Curious, would all the Governors listed above in post #3 also fit a 2001 350 hp ? They do look the same as what I have on the engine.
D-2 governors are the same for different engines and manufactures. My '81 FT, '81 International, '85 3208 and my '99 ISM all use the same D-2
Any thoughts regarding Bendix vs. import?
Jeff,
For the little difference in cost, I always go with OE quality on the air system, including air dryers where factory (OE factory) remans are an excellent choice..
We are talking about something that can leave you on the side of the road and can materially affect brakes and suspension.
Thanks Brett
I definitely agree with Brett! OE quality parts cost relatively little more---and the peace of mind is definitely worth any extra cost.
I was successfully fighting off the urge to post a snarky comment "Buy two." But I agree with Mr. Wolfe about using name brand parts on mission critical systems.
The best example of a manufacturer putting all of their eggs in one basket is Citroen and the 1970's DS 21. A good friend of mine had one and I regret not purchasing that car from him. We rode a good many miles around Pennsylvania in that car.
But. In the center of the gauge cluster, larger than all other indicators was a red light that said simply "Stop." Not caution. Not take me in for service at your earliest possible conveniece, simply "Stop."
Because everything on that car runs on one single circuit hydraulic system. Steering, brakes, suspension, clutch and transmission shifter. Once you lose hydraulic pressure i.e. "The Red Light" you have manual steering, the mechanical parking brake, the suspension drops to its lowest level and you have no way to place the transmission in neutral.
So the larger Foretravels are somewhat better, but the air supply is still mission critical.
I don't know what do do in an air loss situation, but I guess I aim for the side of the road and pull the emergency brake knob to vent the remaining air in the rear circuit and bring my U225 to a controlled stop.
Actually, this will happen AUTOMATICALLY!
Emergency/parking brake is spring applied, air released. So, if air pressure drops too low, the emergency/parking brake will automatically apply.
Easy to confirm:
Block wheels so coach will not roll.
Start engine and build air pressure. Release parking brake.
Turn off engine.
Fan brake pedal to lower air pressure.
Parking brake will engage as air pressure drops below strength of "spring apply".
If you prefer to only use D2 governors with the "Bendix" name on them, keep an eye on eBay for good buys. They come and go.
I have purchased both "Brand New Old Stock" and "Authorized Remanufactured" Bendix D2s on eBay for under $20 (free shipping included).
Those I have received seem to work fine. Sometime need to adjust the pressure after installation to where I want it (100-120). Easy to do.
Example below of one being offered currently. I have no knowledge of this vendor and am not necessarily recommending them.
Pays yer money and takes yer chances.
Bendix OR275491 D-2 Governor | eBay (https://www.ebay.com/itm/Bendix-OR275491-D-2-Governor/233400449250?hash=item3657c038e2:g:c2AAAOSw2WJdyz7g)
Lots of offers on eBay. Read them carefully. If it says "Bendix style" or "Replaces Bendix" then you are probably looking at a knockoff.
Genuine Bendix D2 governor | eBay (https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Genuine+Bendix+D2+governor&_sacat=0)
Let me clarify my earlier post. There are several quality U.S. OE manufacturers of air governors, not just Bendix.
For air dryers, I stay with OE brand because all connections and mounting will match up.
Thanks Brett. I imagine that if I see a steady loss of air pressure, fanning the brake pedal will give more of a controlled stop than pulling the big yellow knob?
YES, brake pedal uses all 4 brakes.
But if falling air pressure, do NOT FAN, as that uses up what little air you have. Just apply steady pressure.
The "fan to test" is to deplete air pressure-- the exact opposite of what you want to do if you are loosing air pressure while driving.
You would never want to pump your brakes for any reason other than to exhaust the air out of the system. The Springs in the air can will do little to stop a rolling coach in a controlled manner.
So. It takes 60# air pressure to release the spring loaded brakes in the rear. I always understood that to mean that I needed more than 60 PSI to apply the rear brakes. Or am I missing something?
PS Trust me on this. If I ever "fanned' the brakes my dearly departed father would still be screaming in my ear "What Do You Think You're doing? Do you want to kill us?"
On rear brakes the pressure has to build up to release the brakes. When brakes are applied the air is released from rear brake and the spring is what applies the brakes. So when you have no air the back brakes are fully engaged.
If this isn't right I'm sure someone will correct me!!!
Chris
Chris,
Your first sentence is correct, IF you are referring to the
parking brakes (spring brakes).
The second sentence, however, is
only correct if you are referring to applying the
parking brake.
The third sentence is correct in all cases.
For a somewhat wordy but simple explanation of the air brake system, check out the video below:
https://www.youtube.com/watch?v=ZFi957GaxpU&frags=pl%2Cwn
To follow up on Chuck's accurate post:
Front brakes-- air applied ONLY
Rear brakes-- two DIFFERENT cans/methods of application: Regular service brakes are air applied just like fronts.
The second "can" is spring applied/air released (emergency/parking brake).
OK! Now I have a better idea of what is going on in the rear. I had been thinking that the air pressure needed to overcome the air pressure holding the spring brake at bay. My bad. The spring brake only pushes the service piston. So as long as I have some air pressure I have some brakes, and one prolonged application is the best technique for coming to a controlled stop after air failure.
Thanks for the conversation. It really helped me understand.
https://www.anythingtruck.com/product/780-72A3030LS.html
FWIW I watched the YouTube video, nothing new there but I think "evacuate" is the wrong word to use for venting the rear circuit. Wirth and Grufat loves those quick dump valves for releasing spring loaded air cylinders, I'd rather retract the air cylinder with opposing air pressure and have a sensor to tell the system that the cylinder is fully retracted.
The "wedge drum brakes" used on your coach (unrelated to those found on most Foretravels) were very widely used in Europe on MDT's.
I know, at 170,000 miles on our coach with the same brakes (and proper use of exhaust brake) the were less than 50% worn. And, that included a lot of mountain driving SOB (South Of the Border).
We're knee deep in linings here and all four corners seem to pull evenly especially during one in-town highway speed traffic light stop down grade with car in tow.
Sometimes I get so tightly focused that I can't see the forest. Happy to know that I have four wheel brakes even as the air pressure goes down. Over the 33 years we had the 1950 Chrysler I had two brake failures. Luckily that car had a powerful parking brake on the drive shaft.
Actually, the sequence will be:
Diminished braking as air pressure drops, as PSI to the four wheel positions drops.
When it drops low enough to engage the parking/emergency brakes, you will have ONLY the rear brakes-- a poor substitute for all wheels braking.
If air pressure is dropping (actually, if it drops at all below "cut in PSI"), find a place to safely stop! Find and fix the issue before getting back on the road.
Merry Christmas Brett. Please grant me the common sense to know that as the air pressure goes down, the available force to operate the brakes also goes down. And I've slid down a hill on a gravel road in both a 1911 Stanley and my 1926 Ford T Speedster. Both cars with rear wheel only brakes although the Stanley had the good grace to have external contracting brakes on both rear wheels, while the Ford's transmission brake cold clamp the drive shaft tight and leave the rear wheels spinning in opposite directions.
Rear wheel braking force with air pressure from 60# to 0 would make an interesting spread sheet graph.
The spring section presses the shoe cam or wedge when the pressure drops under 60 ish psi. You don't have control over the situation . No pressure = no move
If pressure is over 60 ish the spring / park brake may be released and brakes are controlled by the pedal . The buzzer should stay on until around 80psi.
Newer d 2 seem to run at more pressure. Mine likes the 125 target psi. Oe was 105
Most D2 are adjustable. Set the pressure where you want it.
http://www.plazafleetparts.com/uploads/2/1/9/0/2190100/d-2_governor_maintenance.pdf