I have an older Case 680E and am having trouble with the air brakes. It will not build pressure and exhausts from the bottom of the treadle valves. (they worked ok in the fall) I disassembled one valve and cleaned all areas including seals and sealing faces, but this has not helped. Air continues to exhaust out the bottom of the valve. I hooked up a separate air supply at the tank to ensure sufficient air volume/pressure was obtained and had the same result. Could anything else be causing air to exhaust from the bottom of the treadle valves other than seals within the valve?
Does it only exhaust after releasing the parking brakes? If so you have leaking piston seals in one of the air cans. Remove the parking brake hose from one air can at a time and plug it off to isolate which one needs repair/replaced. THERE IS A VERY LARGE SPRING in these cans, do not try to service one without properly securing that spring! If the air is exhausting with out activating the parking brake release, the problem is elsewhere, possibly the clutch cutout system?
Iantraxco - It exhausts without activating the parking brake release. I exhausts continuously unless I press the brakes. If I hold in the brakes it will build pressure until they are released.
Can you isolate it to one treadle valve?
Scott; Everything in your 680 E air brake system (including a treadle valve overhaul kit) is available at NAPA or any heavy truck repair shop parts counter. If one or both of the air brake chambers are leaking don't even consider repairing them. NAPA can sell you a new one cheaper than you can repair your leaky one. Plus it is a lot safer.Unhook the air discharge line at the air compressor and connect a shop air compressor onto it. You can look for leaks with the tractor engine shut off by doing that.
My vote is the treadle valve(s) needs to be replaced. It sounds just like ours did if they were froze up. If they leak without releasing the park brake, they are not holding air internally. Th clutch cutout is just an air operated hydraulic valve that disengages the shuttle.
Both valves are exhausting, but one more than the other.
Tinkerer, Thanks. I will take the valve to NAPA and see if they have an overhaul kit. The shop air suggestion is a good one, that's how I found my problem. Shimmy, Thanks for your input. I agree it sounds like it is frozen (perhaps some corrosion).
This is most likely what you have for treadle valves. The image is from a 680CK service manual. This link will give you an idea as to the cost of a new one. http://www.anythingtruck.com/product/061-286171X.html Those valves are a really hard to get at. To make it a whole lot easier I used a 4 inch grinder and cut the floor plate from the bottom all the way to the top next to the accelerator. I welded a 1"x2"x1/8" steel strap on the underside of the left side and left 1" of it exposed so I could bolt the left side of the floor plate onto the strap. I drilled the strap and welded 1/4' bolts to anchor the left side of the floor plate.
Tinkerer - This looks to be the valve. I think it is a Model E-2 or E-3 single circuit valve. I assume that the E-2 and E-3 have the same mounting bolt pattern. Thanks for the reference to anythingtruck.com. Their prices are competitive. And you are absolutely correct, the valves are a pain to get to. Thanks for your help on this one.
Thanks everyone for your help on this one.
If you need a brake chamber don't buy it at NAPA. They would charge you $134.00 plus tax. Here is a link to one a little cheaper. http://www.nickstruckparts.com/sb2424s.html . This is why I advise to get new ones and not attempt to repair old ones. It should be a perfect fit and you will get new caging bolts with them.
Tinkerer: Thanks for the advise and reference for the brake chamber!
Hey Tinkerer, Is there a pictorial of the Valve from the manual that explains the ports like this one. I cant figure out if this is direct replacement since mine doesn't have factory treadle valves
I don't understand your question. The page from my service manual is all I can provide for visual reference. The only thing that may be a problem for you would be how the pedal attaches to a new replacement. But, you can get replacements with a new pedal on them.
Sorry for the confusion. I am trying to figure out if the supply and delivery ports are in same location for all valves, once I get orientation of valve correct, lines will hook up the same is what I am hoping.
Ok, now I know what you mean. Yes the ports on the new valves should be the same as the ones you now have. If there is any doubt in your mind clamp the new valve in a vice and apply compressed air into the appropriate port. Then operate the valve to determine what each port is for.
Well, it appears that I have crossed a line or these new valves function in a way I still dont understand. I am only able to reach about 20 psi and there isn't any air leaks I can hear or feel. I think I must not understand the supply/reservoir,deliver vs . Some how I placed a line or placed a plug in wrong place. I even had it patterned along the lines of the old valves I removed. They leaked so bad tho I couldn't test anything on the bench when I used shop air. Wish they would have some sort of marking on the original valves. According to the Case picture I am seeing the side of the valve closest to the battery box correct? So left side would be on door side and right would be closet to throttle pedal?
Those pictures are of two completely different valves, the one on the left is for a split system?
Lantraxco, could you elaborate please, you and Tinkerer are a wealth of knowledge and for the price a dealer wanted if they could find the correct valves was outrageous. Would you or Tinkerer know which valves would be correct for my 680CK?
Although the 680E air reservoir is located differently than a 680C the air routing should be the the same.
Thanks Tinkerer them are the schematics I used also. Is it possible I may have gotten the wrong valves? They bolted up, and the old valves were one large and one smaller valve.I am just going by Lantraxco reply as I am new to this air brake system.
The valve in the picture on the left if you notice says "supply 1, delivery 1, supply 2", etc. It's designed for a system with two separate tanks and separate air lines to front and rear axles, or split rear axles with the front connected along with one rear, safety deal on trucks. The valves shown on the right are bone simple single supply valves, every truck on the road with air brakes just about had one of these until split systems and ABS came along. I'm betting it's a Bendix E-3 or a copy of it. Any parts store should have these in stock. Examples: http://www.anythingtruck.com/product/htp-brake-air-valves-foot/061-277863X.html http://www.anythingtruck.com/product/htp-brake-air-valves-foot/322-GN277863.html
Lantraxco you are correct! I ordered the wrong valves.
No worries, easily fixed, eh?
The way the system was plumbed for the last 12 years I have had it there was an E6 valve on left and an E3 on the right. So I don't think they were original at all.
Well, I guess that an E6 would work, just leave one section disconnected. Somebody must have just had one and threw it in?
96_Bear; Please post back and let us know if the E3 valve is the one that finally worked for you. I overhauled my valves several years ago with rebuild kits from Case and I think they came in a Bendix box and were for an E3.
The schematics I have are quite different from a 680E air brake system. I hope mine doesn't cause more confusion. I may be wrong about my 680C using an E3 treadle valve. I think it may have Midland KN22100 valves in it. The piping may be the same, but I think the the top of the plungers are different between the E3 and KN22100. I should still have those old (used) repair kits somewhere in my garage. I will look for them later today.
I found the the repair kit. It came in a Case branded box, the instructions inside the box were printed by Bendix and were for an E3 valve.
I am suppose to get the new E3 valves tomorrow. The valves I had according to Napa once we tore them down is MB N300998 325 and T239649-C with the numbers we can match up.
I have been chasing a slow air leak on my tractor for quite a while. So far I have replaced all the air lines with hydraulic hoses, installed a new check valve in the supply line that goes to the reservoir tank and two new brake chambers. I used a grease gun hose to replace the line to the air pressure gauge. I also put in a new parking brake valve. I just purchased two new treadle valves from two different vendors on Ebay. I bought one of them (a Midland KN22100) for $15.00 delivery included. Also the second one (a Bendix E3) for $35.00 delivery included. If the leak persists after I install them the only thing left that could be leaking is the regulator that supply's air pressure to the hydraulic tank.
I work in industrial maintenance and had a problem of an air leak that we couldn't fine also. I just by chance found the air gauge itself was leaking.
Thanks to Lantraxco and Tinkerer, got the correct valves and everything is working correctly. Found that I have (maxi) brake chamber leaking. Going to try Napa and see what there cost is to get a replacement. Going to search this site and others and see if there is an updated part number that will make it a once and done, the 2 numbers I have now doesn't cross with anything I have found yet. L54297 has been superseded by L73801.
That's a pretty common old style piston can, don't be afraid to update to a newer style as long as it's the same size. Any good truck shop should have what you need if Napa strikes out.
Looks like Tinkerer used this one http://www.nickstruckparts.com/sb2424s.html from earlier in this thread. I am trying to see if the numbers will reveal the info I can cross reference. I am going to have to cut the old one up to get it out so I'm not certain how much is going to be identifiable once I am done. You both have saved me a lot of headaches and cuss words for sure!
You DO realize that there's a honkin ' big spring in there right???? Cutting on spring brake cans is verboten in my world! As a guess that new style can looks like it should work. If the outside diameters are close to the same, should be fine.
LOL yes I do, I am going to have to cut the rod at the clevis and maybe have to cut the clevis also from the looks of things. I have dealt with huge spring in robot return canister, during a training class we got to see where one got away from instructor during a rebuild and went thru a block wall and embedded in an concrete wall about 20 feet away!
All good, nuthin' to see here folks, move along now, lol.
I don't think you can cross reference your Case OEM brake chambers Bear. Those 24/24s should bolt right in. Be sure to cut the rod on the new chamber to the exact length as your old one. You shouldn't need to cut anything to get your old brake chambers out. Remove the nuts on the mounting studs then the pin should come out of the clevis. If you have to you can charge the old brake chamber with air to help things along.
Thanks for the tip Tinkerer I will try the adding air to see if that helps. After checking air loss,1 hour later and I had only lost 20#'s of air pressure. So once I get the air chamber replaced I should have this old machine going good!:drinkup
Hi Scott, did you replace the treadles? I need to do this on my 680g. Do you have any part numbers?
I’m looking for the Napa part number for rebuilding the treadle valves on my 680g. Anyone know what they are?
Case treadle valve #L73042
Thank you
You can buy those treadle valves at NAPA and a lot of other retailers. Take your old one in and they will sell you duplicate of it. Rebuilding one is waste of time. Thousands of them are in trucks with air brakes. I have purchased some really cheap ones on EBay. Getting the pin out the pedal can be real easy if you drill an acess hole for it the side the tractor cab.
Thanks Tink, I was wondering if they just look at the amount of air ports to match up a new one. Didn't know if they had some special way they worked.
Do you buy a new pedal? Or does the new valve fit the existing one?
The pedal mount is mostly all the same on the Bendix treadle valves. The unused ports are plugged with 1/8” pipe plugs. I should have said in my other post that you would need a long punch to reach the pedal mount pin through the new hole in the cab.
I’m not sure, but the 680g may be different. I was able to remove the cap screws (with 1/2” wrench) from the cab, after I removed the air lines (by access through the battery compartment) and removed the valve from under the mounting plate. I did use your advice and drilled a hole to remove the roller pin, but not the hinge pin. This allowed me to push the pedal down to access the cap screw under the heel area of the pedal. I’ve ordered 2 Halidex valves from Napa today. 80$ each after core return. They look the same as oem. I’ll post the part number after I confirm the fit. It was a tough job getting it out. I had to make a platform to lay across the rear fender, to get my head into the battery compartment. Thank you.
I ordered 2 new valves from Napa and they fit perfect. No adapting at all. Napa Part number PART #: MBI 277863X