Geoff Weeks

In this exploded diagram the possible leak points not including the solenoid valve are: 1) between the top face of part #6 and the body of the valve. Look for crud stuck in this location 2) O ring #10 seals valve # 6 to retainer #11, a bad O ring here would leak out the bottom 3) A bad O ring #9, unlikely as the is a stationary seal between # 11 and the valve body. Of the three situation #1 is the most likely, followed closely by #2 O ring # 10 has to seal # 6 which slides in the O ring when valve #6 moves off its seat. When at rest (no brake applied), any pressure in the outlet port vents out the center of part #6.

All the outlet ports are marked with a red X

The two pipes go to ABS actuator valves then to hoses to the brake chambers, Make sure the brake chambers aren't backfeeding. The ABS valve on either side are just straight through unless the ABS is in action. The 3rd hose on the bottom should go to a quick-release on the spring brake circuit to prevent compounding (anti-compounding QR) . Any of these could backfeed it there is a problem "down stream" all would only leak back when the parking brake is off. If your valve leaks with the parking brake on, then it is the valve itself. If it leaks all the time, whenever there is pressure in the air system, it is most likely the bottom portion of the valve, which can be taken out and cleaned and new O rings install by removing the snap ring (spring loaded parts behind the snap ring, so be ready to ketch them. There is a small chance that solenoid valve on the top has a small leak, and I think that would be harder to repair/get parts for. For the cost of O rings, I would start at the bottom of the valve, if it leak all the time there is air in the system (parking brake on or off)

That Bendix number come back to the ATR-6 which is what I posted the manual on.

In the link I posted to the Bendix "manual" on that valve, it is all just plain O rings, and the manual even lists the size, so you can go to where you buy O rings, and have them all before you start. There is a small chance that there is a small (internal) leak from the solenoid valve on the top, but think it is much more likely a piece of crud is stuck in the valve, disassemble, inspect and install new O rings. Cost would be the cost of the O rings, but if you have a good supplier, then less than $20 would be my guess. Follow Mecho's testing to make sure it isn't some other valve backfeeding into this one. edit: If your a gambling man, leave the valve in place, don't mess with the top 1/2 and only take the snap ring off the outlet, and remove and replace the O rings that come out the bottom, clean the valve seat where the delivery valve seats. That is the most likely point of failure. Just two O rings.

Not really, if you changed the whole chamber, with a service 30/30 you will be changing the correct part. I still have E brake chambers that you can service the spring brake side, either diaphragm or piston type, but those are what? 30-40 year old? When did the "idiot proof" "sealed chambers come out? Diaphragms leak to the outside, the piston rod seals leak chamber to chamber, but with the idiot-proof chambers, the only way to fix is to replace the service 30/30. In the old ones you can take the big Phillips head screw off one piston, remove the interchamber rod and replace the seals, though not many did.

If it is infact the valve, most of the likely O rings and any dirt on the valve can be reached from below by removing the snap-ring and delivery valve. The O ring sizes are listed in the Bendix breakdown I posted.

It will not be a diaphragm, they leak externally, it could be the O rings on the piston shaft of the maxi section, they can leak from spring brake air pressure into service brake side. Without knowing where the other line on the valve goes, I can't say what it could leak back. Might be inversion valve or anti-compounding.

The big "green" line closest to the camera should be supply. The 3/8" line near the top should be signal. It would appear the valve has 4 outlet ports, two on the side and 2 on the bottom. In the picture one of the bottom ports is plugged and it looks like the line I asked about goes into the other bottom outlet port.

In the pic, there is one line that appears to be hooked to the outlet of the relay that is not connected to a ABS modulating valve. Where does that one go?

I thought of asking, but a test of the output lines would give a good indication. Not being 100% sure of what the valve is hooked to, knowing when it leaks needs to know how it is used. K.I.S.S., if air is leaking back through the output, how the valve is used, is not important, it isn't the problem.

I think the two valves are more or less the same. The one with the solenoid on the top cover allows it to be used with traction control, the other is ABS only, as it requires treadle valve pressure to operate the relay portion and the ABS actuators are on the outlet. The ABS/traction control version allows the traction control to open the relay valve independent of the treadle valve, then the ABS controllers work and apply brake pressure to the spinning wheel and keeping it from the non spinning. The solenoid valve take tank pressure to operate the relay to "full open" while simultaneously preventing signal pressure back up the treadle valve line and out the exhaust at the treadle. regardless, I'd want to make sure none of the delivery lines are some how feeding air back up to the valve. Any air would vent out the exhaust of that valve giving the impression that the valve is "bad" when in reality it is doing what it is supposed to, vent any pressure from the brake lines when not called for by either the treadle valve or the traction control solenoid.

Don't think it is,there is an electrical connection on the top from what I can see. Needs to be better I D to be sure. Looks an awful lot like a traction valve. I could be wrong.

Hard to say for sure, but looks like this is the valve. Ad for picture ID only. https://www.ebay.com/itm/305180616028 Parts breakdown and procedure: BW2598.pdf

1st order of business is to make sure it is the valve that is bad. Remove the outlet hoses/piping and see if it stops leaking and air is coming back up a line from a defective brake chamber. Far better to find that out now, not after you have spent the $600 and wrestled it out of there.

I would try that 4.10 before changing anything. 4.10 with .73 OD on 20" rubber is where I ended up, and liked it a whole lot better than the same with 3.90.

unfortunately, there are plenty of trucks being driven by people who shouldn't have been given a CDL, and there background has nothing to due with it.

I got a simple question for y'all, would you feel better if he was a citizen? "cause I've seen plenty do that, and get lucky and not kill someone, including myself as I had to dive for the shoulder on I-55 when someone pulled a U turn in front of me, What is of issue the the quality of people with CDL's much more then where they come from. I've lost count of the stupid moves I've seen in my time on the road, from every state, there is no exception to the stupidity I have witnessed. It is all done by someone who was issued a CDL by some state authority. The big issue and tragedy was the driving actions, not where the driver is from. He got what he deserved in prison and expulsion, but what causes is the action behind the wheel not being from somewhere else.

try Stangle bro. Fullerton, Pa.

I think there was even a 17" at one time. I know we were looking for something to replace the British bus 17" and saw Mack had one, but too much was different. Had to get our clutches air freighted in. Didn't have to do many but they were expensive when we did.

You're thinking commercial use, Larry the only driver and being used the way he is, any clutch should outlast 7 lifetimes. It depends on what can be found, and how much has to be bought, which way would be best. I wouldn't pay a premium for "common" in this case. As I have said before, I ran 14" organic clutches and they outlasted the engine builds. I was doing commercial and some heavy haul with mine.

glaucoma, I believe is measured in pressure in the eyeball. Something best dealt with sooner than later.

I stand corrected. It is like the "no recaps on steer" on trucks, everybody says it, but that isn't what the law says. I thought spring brakes were a requirement on stuff newer than early 60's late 50's. Tru-Stop disk driveshaft brakes would meet the stopping requirements (I was told) but lacked the self-applied function, so they faded away from use.

I would think anything by 1965 would have spring brakes? The requirement came in in the very late 50's IIRC Edit: I am having trouble finding a statute that spells out exactly when "self applied" e brakes were required, so I may be wrong. I have always seen auto applied spring brakes on stuff newer than the 50's.

The newer Eaton's are like that. direct is one gear down-high. A overdrive front box with an underdrive splitter all plumbed for seamless progression (unlike the older underdrives). Gives 2 OD ratios, but not big jumps.