| Author | Message | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 369 Registered: 2-2001 Posted From: 69.77.157.8 Rating: |
Well, as the title says, I was hunting for something else this morning and stumbled on the answer to the identity of the air application valve that is installed on my 4104. It is a Bendix clutch air pull valve. (I tried to attach the file but it's too big) E-mail me if you want the file but it's on the Bendix website. I haven't checked to see if these are available new, but they can't be that rare if Bendix made 'em. The rest of the rig is just an air cylinder & some hoses. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1490 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
My Brill had a brake treadle valve to operate the clutch, with a rotochamber brake chamber attached to the clutch release lever. Worked fine, although was a little tough to smoothly engage; put a restriction into the air line that helped. Some of that could have been caused by the rough flywheel surface with some burned spots and small cracks. | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 72 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
John, Was the set up with the brake chamber a stock item or a PO modification. It sounds interesting as I need to figure something out. My left ankle is weak from a childhood accident, and pushing that clutsh is not much fun! Jim | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 73 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
Not sure if this link works here, but this is a cool foot valve I have used at work. A small pressure releiving regulator screws into the end, and the furthur you push down, the more air you get. Take you foot off and it lowers the pressure proportionally. Really simple. I just brought one home to play with and I'm going to hook it to an air cylinder. I was thinking it would make a great throttle - same idea. http://www.clippard.com/store/display_details.asp?sku=FPA-1 Jim | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 74 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
Jim, I went to the Bendix site and tried various searches but could not find it - do you have a link? Jim | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 243 Registered: 11-2008 Posted From: 4.248.48.71  Rating: N/A |
Not sure this is relevant, but this guy Don from Maryland (who I've written about before) found this valve on my clutch linkage. A couple of turns later, and he turned an 80 lb. clutch into a stick of butter. Still doesn't work but, boy, is it light on the leg! Nellie Wilson | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1492 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
The clutch pedal was a common airbrake treadle, although I would use one that has more "feel", which Bendix makes. The mounting bracket at the bell housing looked to be homemade, but workmanship was pretty professional, so it might have been a factory item. I never looked into it. It just worked. It was a rotochamber brake chamber though. The unit Nellie is referring to is what is in my 4104; air assist clutch. There is a sensing unit installed in the clutch rod. Apiece of rod is cut out and this unit is installed in place of the removed piece; about 6 inches long. Then a small compact air chamber is attached to the clutch release lever in the manner that works in the space available. An air supply line is connected to the air chamber; mine has a pressure regulator in that line to adjust the assist. That's it. Pedal pressure is as light as in a car or truck. Can't think of any shortcomings of the system. Still works even if there is no air pressure, although at the non assist effort. If you have no air in the Brill setup, you have no clutch actuation. But, there is no linkage to maintain, just an air line from treadle to rotochamber. Some commercial buses used this from previous postings here. Maybe someone here can come up with a used unit. They may make aftermarket units available for otr trucks. I'm sure there is a need for this sometimes. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1493 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
If you want info on rotochambers or brake treadles, just type word into search on firefox or what you have and all you wanted to know will be available to you. | ||
| Bruce (Bgs4104)
Registered Member Username: Bgs4104 Post Number: 16 Registered: 10-2006 Posted From: 68.126.29.19 Rating: N/A |
Here a photo of the sensing unit Bruce  | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 78 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
Bruce, Thats pretty cool -a picture is worth a thousand words! I am guessing that is a piese of the clutch linkage, and when the rod is compressed by pushing the clutch, that unit senses the pressure and starts air to a cylinder to "assist". Where in the system is that piece of linkage, and does it look to hard to change out? Thank You! Jim | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 511 Registered: 3-2007 Posted From: 71.55.197.237  Rating: N/A |
Hey!!!! that is what I need for my 4104. Have you got a spare on laying around that I could purchase along with the instructions of how it is or was mounted?? Let me know if anyone has one extra. Thanks gomer | ||
| Bruce (Bgs4104)
Registered Member Username: Bgs4104 Post Number: 17 Registered: 10-2006 Posted From: 64.166.166.40 Rating: N/A |
A bus buddy had this in made & stall on his 4106 in a shop where 395 & 58 cross west of Barstow Ca. The shop told him they maid the brain but I have seen them on other old bus too. I had a air assist Steering unit call Air-o-Matic on the brain but I never found out any thing on the manufacture, it looked just like this one but 100% bigger. The photo one replace the rod from the back bulk-head bellcank to the Clutch arm at the trans also needed is a air ram to push on the clutch rod Ie a front brake can will work. | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 512 Registered: 3-2007 Posted From: 71.55.197.237 Rating: N/A |
Bruce, I just went surfing the web, found a company called HB Industries.com in california that has exactly what you have pictured and they do coach conversions also. Click on the left side for depts. Gomer | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1497 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
That piece installs from the shift rod tower to the clutch release arm on a GM. I think the name on my unit is Mardyne. Can't find any info, although I didn't look that hard as I don't need one. | ||
| Mel La Plante (Mel_4104)
Registered Member Username: Mel_4104 Post Number: 121 Registered: 7-2006 Posted From: 99.199.170.124 Rating: N/A |
Bruce would you by any chance know what make that air valve is or what it came off. i have looked all over for one and the fellow in Cal. wants $750 for his system. thanks for any help - mel 4104 | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 515 Registered: 3-2007 Posted From: 71.55.197.237 Rating: N/A |
Mel the source is the one I mentioned above, I am looking around for another source/s. For that kind a money I can shift it a long time,especially when I use it only to start and stop. gomer | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 372 Registered: 2-2001 Posted From: 69.77.157.8 Rating: N/A |
The one on my bus is not original but it is the stock Bendix unit. Here is the link: http://www.bendix.com/en-us/service/library/Pages/Catalog.aspx (part way down under "valves" 03-A-19B) The P.O. had an air cylinder that was about 1" dia and was not long enough to allow any clutch wear so it ended up keeping the clutch from fully engaging and it burned out the clutch. The 1" dia did not give enough force. I went to a big dia cylinder, nearly 3" and about 6" travel and it never needs to be adjusted. I also mounted a brake light switch in an unused port on the cylinder & wired it as the disconnect switch for my cruise control. It's as easy as a car clutch when there's air & will work even if the air system fails. | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 91 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
Just curious, is the valve that is installed in the linkage a variable valve that applies more air to the assist as it is pressed harder, or is it just an on-off that once is is engaged, adds a fixed amount of assist? Jim | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1505 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
fixed amount of assist. To adjust the amount of assist, you put a pressure regulator in the feed line to the sensing unit and set it to your preference. That Bendix reference is for a pull type clutch; ours is a push type. | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 101 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
Interesting. If it is just an on-off, is it reasonable to use an electric pressure switch on the clutch pedal, or a microswitch somewhere on the linkage near the clutch to drive a 12v air selenoid to the brake can? Seems it might be simpler than the in-line air switch. Thinking outloud. Jim | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1512 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
In that case, when you touched the pedal, the switch would activate and engage or release it with no control. | ||
| Mel La Plante (Mel_4104)
Registered Member Username: Mel_4104 Post Number: 122 Registered: 7-2006 Posted From: 154.5.113.177 Rating: N/A |
well i am still looking for that valve, however being a guy with a GM bus i never looked at prevost or mci and now i find out that both buses with manual trannies had them, so when i find out cost of their parts i will post it. | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 103 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
John, Seems that if the switch were set such you had to get the linkage moving and off the throw-out bearing before it closed the circuit and applied air for the booster it would have control. The booster does not fully depress the clutch, it just adds some help. You would still be required to press the clutch pedal to fully disengage the clutch, it would just be easier because of the assist. When you let the clutch out, the same would happen, the boosted would be adding pressure, but you would have to let it out. When it got to the point where the clutch was released all the way, the microswitch would let go the air to the booster and you would be going. Once the boost was gone, the linkage would go to it's fully rested position so didn't toast your throw-out bearing. Again, I have never seen one of these devices and trying to understand how they work, and it just seemed like a switch might do the job. I think the problem with a switch and this idea might be that the clutch might never come back to a rest position to let the booster go, and you would always have the boost abblied and a slipping clutch. Not good! I wonder how much pressure that in-line air switch takes to activate the boost? Jim | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 350 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
Jim I had a look at the Bendix page, and it looks to me that the valve will produce variable pressure. Mel The set up on MCI and Prevost is done differently. I should try to scan the page out of Da Book and see whether I can post it. Joe. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1522 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
Not only the clutch slipping but the throwout bearing spinning constantly, causing premature failure. I'm sure it could be made to work with some fiddling. | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 109 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
Joe, If the valve is giving a variable pressure output, that makes a lot of sense, and explains why a simple switch is not used by anyone. I can see how the variable would do a great job, and give the driver a full feel and control, whereas an on-off would have that poing where the boost wend off, and would cause an abrupt grabbing of the clutch. Interesting stuff, and one am am very interested in adding to my coach. Jim | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1524 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
Just got this e-mail back from Maradyne Corp. from inquiry of the air clutch unit, which they manufactured: I apologize for the delay in responding. I wanted to be sure we had nothing in house that you might be able to help with what you need. Unfortunately that product line was shut down and obsoleted many years ago. We currently have no parts, prints or materials available to supply you. I had looked for the old purchasing cards, that I might direct you to one of our suppliers, who might have been able to make or supply some parts for you. But I had no luck with that either. I’m not sure if there is another company that might make a similar item, I have no knowledge of any. You might try a web search? Sorry we are unable to help. Best regards, Adrian Halcomb Maradyne Corporation PH 216-362-0755 Ext 137 |
