Brake foot valve plumbing - please explain?

Hi again knowledgable brethren, yep more questions on the old White... :
Been having a few intermittent problems with the foot valve for the brakes (brake lights staying on and the brakes felt like they were dragging a bit). So she now has a brand new single circuit E6 (I think he called it) foot valve and brake light switch. Fixed the brake lights staying on,, that don't happen anymore and neither does the brakes dragging, but now...

Driving it all of today, I notice that the brakes are extremely touchy. I have plenty of clearance between the pedal (the roller on the back of) and the plunger that actuates the valve. To best way to explain it, If I apply finger pressure to the brake pedal it will near stop the truck from walking pace. If I dab the pedal hard with my foot, the foot valve will "squawk" but will also stop OK. The drum temperatures all apppear to be similar - f&$kin hot front and backs, but that is Gold Coast traffic with 13.5 tonne on board. :

I am beginning to wonder if it is plumbed right. To make sure it went back together right, the whole thing was written on the white board before pulling apart, then the lines were tagged, and carefully put back into the respective holes after fitting the new valve.

The new valve looks identical to the old one, except NEW of course. It has 4 ports in the upper section and 4 ports in the lower section; all holes are the same diameter.

Does anyone have a sheet or other means of explaining how these things work and/or most importantly what line should go where? It may have been plumbed wrong for years as i have always had brake problems with this old chook. All rear axles are spring brakes while the front axle is air activated.

I reckon Swishy will have the appropriate sheet somewhere and most likely BigCam will have the summarised version

Anything that you guys can dig up will be a help; 2 different truck mobs gave me two completely different plumbing instructions today - and both of them different to the way it is actually done.

cheers and thanx in advance
Bretto

Giday bretto i found this on the E6 ,i may help or confuse you worse! might get ya goin till swishy or big cam chime in mate!


Dual circuit brake valves utilize two separate supply and delivery circuits for service and secondary braking. The number one or primary circuit portion is mechanically operated through the action of the treadle/pedal and plunger. The number two or secondary circuit normally operates similar to a relay valve, with control air delivered from the number one primary circuit. In the emergency mode (failure of the primary supply), the secondary inlet valve is mechanically opened by a push through mechanical force from the driver's foot via the treadle/pedal, plunger and primary piston.

The E-4, E-6, E-10, E-12 and E-15 dual brake valves are floor mounted, treadle operated valves with two separate supply and delivery circuits.

Yep, you are right Adam, confused me more
That is the right valve though, so that is something, but where the pipes go, ummmmm, yer
Bretto

Bretto, all the directions are marked on the valve.
Delivery to the front QR valve,
Delivery to the relay valve at the rear
Supply, air from the tank
And you may have another air line going from a "Supply" port to the air gauge.

Hi Cam, the Eaton valve I got has absolutley no markings on it at all - hence the problem. Nothing in the box either. Only marking on the valve is a cast number "6" - that's it.

Of the 8 ports on the valve, 7 of them are used and 1 is plugged (unused).

Maybe i should take the time and do a drawing or something to show how this one is plumbed and then we could all see if it is right or not.

Bretto

Have drawn it, how do I put up a word document to show the drawing??

maybe it should be and e3 not an e6
i stand corrected, i think my tranny has e3 as do early kenworths.
they are not exactly the same, but i think have been interchanged in the past, i think the main difference is in the pedal end of the plunger?
if im wrong, so be it,
regards
chocs

E3 is the earlier single circuit valve.

At first glance the E3 and E6 look similar but the porting and operation is different.

These links to pdf's on the Bendix site provide a bit more info.

www.bendixvrc.com/itemDisplay.asp?documentID=2806
www.bendixvrc.com/itemDisplay.asp?documentID=2800

and a heap of other info in the Bendix document library

www.bendix.com/en/servicessupport/documentlibrary/doclib_1.jsp

That confirms what came off was an E-6, and what went back on was also an E-6.
But the bendix document library, all 108 pages of documents, doesn't say in clear language what port is used for what purpose - in other words what hose from where goes where. Bugger. :-[

Acccording to Bendix, the E-6 valve is a dual circuit valve.

This might explain why when I took off one of the lines at the valve that goes to one of the brakes, all brakes still applied but air rushed out where I took the line off the valve. It apppears that if one circuit is interrupted, then the other circuit takes over and still feeds all brakes?

I'm still none the wiser - maybe I need to take some smart pills or something but the penny just hasn't dropped on this one just yet.
Bretto