Need help sourcing this air valve or variation of it

Bill in KS · August 16, 2011, 07:34:00 AM

Previous owner had photos and plans to install an air clutch on the coach. I have the correct air cylinder to move the clutch arm but not sure where to find the valve to install inline. Below is what the setup called for. Where is a good place to purchase this valve or something similar for less money.
thanks
Bill in KS

bevans6 · August 16, 2011, 08:36:28 AM

Did you call Bendix and ask them? That would be my first step. I would love to see a diagram of the whole setup. That valve looks to me to be an air cylinder on the bottom to create a mechanical pull movement on the top via the lever marked no. 11 in the diagram. It's still in the Bendix website, which is a good sign. http://www.bendixvrc.com/itemDisplay.asp?documentID=2757

Brian

Bill in KS · August 16, 2011, 09:29:11 AM

Hey
I called a bendix dealer, they want 1200 bucks. Makes the air clutch setup from HB look much better. I want to keep my OEM parking brake and have people that can make my mount brackets, I just need something to activate the large push cylinder.

I've attached the photos I was provided when I bought the coach from the widow.

Keep the ideas coming
Bill in KS

bevans6 · August 16, 2011, 10:36:51 AM

what do you use to control the whole thing? it looks to me like the "clutch pull valve" is an mechanical over air pull cylinder that pulls on the clutch arm when you apply air to it - from a treadle valve of some sort? the big cylinder is the air assist part - it must have air sent to it to push on the clutch arm to assist the pull that the little valve generates. what controls the air feed to the big cylinder? How is the air plumbed?

Brian

Bill in KS · August 16, 2011, 10:48:41 AM

I think pressure is supplied to the inline valve, upon movement of the inline valve it begins to meter air to the push cylinder. Hoping someone might chime in and provide some knowledge.

Bill in KS

bevans6 · August 16, 2011, 11:00:45 AM

I think I had it backwards. The clutch pull valve is the control piece, I think, when it is pulled you get a flow of air to the output which goes to the assist cylinder which helps push the clutch arm along with the mechanical pull from the clutch pedal. The trick is it doesn't sense the position of the clutch pedal and pull rod, it senses a certain level of tension on the pull rod. You could look for a similar electrical switch that needs say 50 lbs of pull to switch, and have it control a skinner valve. The idea is that when the clutch is up, the air assist has no air so no pressure. As soon as you press down on the clutch and take up all the free play you start to pull on the pull rod. After you pull more than say 50 lbs (around 5 lbs pressure on the pedal, there is a 5 or 6 to 1 ratio between the pedal pad and the pull rod movement) you switch on, your air cylinder gets air, and you get assist. You can tune the amount of assist you get with an air regulator. A 2.5" air cylinder develops just under 50 pounds of push for every 10 PSI of air. with your pedal ratio at 5 to 1 (you can measure to see what it actually is) every 10 psi of air will reduce your pedal pressure by 10 lbs. Since your air assist cylinder is attached to the clutch actuating rod between it's pivot point and the pull rod attachment point - what ever that ratio is will also reduce the amount of assist you get.

What a great idea! I may use this myself, if I can figure out a way to switch it.

Edit - I drew up a quick design of a switch that would be the electrical equivalent of that mechanical air switch, and would control a skinner valve. I would put it under the floor at the front, for easier access and better protection. I think this idea has merit. Thank you very much for posting the pictures and asking the question. I'm sorry I don't have any ideas about the air/mech switch.

Brian

rusty · August 16, 2011, 12:28:38 PM

Eagle uses a very similar valve. Jefferson in OK city has them ( rebuilt ). Also there are a lot of Eagles being parted out, that control valve is probably thrown away. I am using that system on my 15 to assit the hydraulic clutch. You can see it on the Eagles web site under Projects my project is Wayne schell 15. I think I started to talk about it on my last post.

Good Luck Wayne