My 230 Cummins has a fuel leak that appears to be coming from the crossover tube between the front and the middle head. Who can tell me what I need to do to fix it? Thanks in advance.
First blow out or pressure wash it between the heads, If it has jakes remove them. Most of the time it will require one of the rocker boxes be removed, But if one crossover is leaking you may as well do the other while you have the center rocker box out of the way. Then re-seal and run the over heads while your there. Should be a small cam but best check before you make a mistake like someone else did.
Thanks, I have been into one before but it was 10 years ago, I changed the injector o rings and I got it back together and it ran....b bu it took me a while.Maybe I can do this job a little quicker!
Yes defiantly want it nice and clean down there before you loosen the screws that hold the jumpers in place. Need a set of eight of the right size orings. I'm trying to recall but wasn't there a change to those jumpers. Seems the plate the screws go through were solid and then they changed to ones with the bottom plate split. Think it had something to do with a problem getting them to seal if two adjacent heads were a slight bit different in height due to on being milled during a rebuild. Truck Shop, am I remembering right? Think it has been something like 20 years since I did more than change oil on an 855!
Your right.
Had that problem with my 250 last year. The rear one was no problem other than trying to get the screws loose with an impact driver. The front one had a lifting bracket in the way. I cheated and took a bolt out of each rocker housing. Then R&R crossover o-rings. Now a truck with with a L10 pump has a leaking throttle shaft. Had a lot of o-ring problems when low sulphur fuel came out. Is this a repeat with Ultra Low Sulphur fuel?
I like to add a little hydraulic oil to the low sulphur fuel.
Nige, didn't we have a short discussion about low sulfur diesel?
I inframed that engine in the early 90's with an aftermarket kit. Poor quality o-rings no doubt?
Would you,or anyone else that happens to read this, happen to have a part number or size number for the o-rings ?
I believe the Cummins part number is 152946 for o-rings. If my notes are correct.
I wouldn't call it short........ You are referring, I assume, to fuel lubricity numbers..?
That be the discussion.
I am interested in the discussion you two had on that.
Fill your boots......... HeavyEquipmentForums FYI we burn between 15-20,000 gallons a day of ULSD.
Thanks, I read it and it opens my eyes a bit! I WAS one of the "add some oil" guys but I am glad to hear that it is not helping as far as wear is concerned.
When I posted the link I was hoping that you weren't one of the "I've got my opinion, don't confuse me with the facts" people like most of those who apparently frequent the Diesel trucks forum........
Arrr and who might that be?
I went by the Cummins dealer near me a while back and picked up a couple of o rings that were supposed to be this number and they look to be way too big. Do you know what the dimentions and what material is best for this that I can pick up maybe at Napa?
Just take an old one with you and match it up. They are nothing special and I plucked mine out of a standard $25 o-ring kit in a box. You know the poor quality o rings was a joke as they were over 25 years old. Some of the throttle shaft seals were different. Reducing the amount of sulphur after long time use seems to shrink the o-rings.
Thanks, I guess that's what I will do, I was hoping to get them before I tear it down to reduce my down time, not that I work it every day but I have a tendency to let things set if I lose focus...a sign of my old age,lol.
Truck Shop,would you happen to know where I can view a thread on running the overhead on this engine? I had the front rocker box off and I wanted to at least check the rocker adjustment on that one while I have it open,thanks.
Don't know any videos. Firing order-153624. 1A, 5B, 3C, 6A, 2B, 4C. Bar engine over at accessory drive, clean back edge of accessory drive to find valve setting marks, 1-6 vs A, B, C. Bar engine over till both exhaust and intake valves are closed on #1 and #6 exhaust is just closing and intake just opening. Check accessory drive 1-6 vs should be lined up with pointer on accessory drive cover. Set injector first at 70 inch lb. Exhaust rocker 023. and intake rocker 011. Bar engine past B rotating till B comes up the second time on accessory drive pulley, stop at pointer. That's #2 cylinder, both valves should be closed. Check those rockers. This procedure is for a small cam.
This is a NH 230,it does not have the timing marks like a NTC does,I'm not sure where to look.
Sand the edge of accessory drive pulley, it's there.
I have a manual that explains the process real clearly for a NTC 300, is it the same thing for this NH230 ?
I finally got it cleaned enough to find all of the marks,couldn't find a mark on the cover but there is a lug that I assume is for this perpose. I'm having trouble figuring out if I'm on the right stroke or not. Is the valves supposed to be up or down?
Both intake and exhaust will be up and rockers will be loose. The marks on pulley will line up with the pointer/lug on cover and both valves will be up/closed.
Ok,thanks,I have the box off of 1 and 2 right now with the pointer on A and the valves on 1 are up. So I should loosen the rockers and set the box on,bolt it down and then adjust the injector and the valves on 1 correct?
Just install that rocker box making sure the push tubes are in correct positions. Torque to 15 ft lbs. You should see that both rockers have clearance. If so finish torqueing to 70 ft lbs. Remove rocker cover on back cylinders and check to see the rockers on #6 are in a state of just opening and closing by baring engine back and forth. That will tell you that the engine is on #1-A and not #6A.
MAKE CERTAIN by shining a light down the pushrods that they are seated in the Cam Box Followers. Buddy of mine did NOT, ate a follower BOX(cracked it) and the cam that required changing. While have the boxes off is a Great point to check the Push Rods for oil filling, will miss like has bad injector if any have done that.
Yep can tell the difference in the sound the push tubes make if you tap them on something like the frame or anything hard. They should sort of ring if empty but if full of oil will make a real dud sound.
Good point-I was in a hurry to get to work this morning. Refer shut down.
I had to read back through until I found this comment you made,I'm about to run back through the process and back off of everything as I come to each cylinder and then set the injector and then the valves. I just wanted to double check the injector sequence and torque. I was feeling a little unsure because the only one I have evr done was a NTC300 and from what I understand it had topstop injectors and I used a totally different method on them compared to this NH230. Am I thinking straight on this sir?
Just realized how old and out of date I must be when it comes to Cummins engines. I worked on many over the years but only ever had the chance to adjust the injectors in one with top stop injectors. And probably half the others were before Cummins came up with the Injector Travel method!
Two different injectors and two different methods.
I have an 855 small cam with the same problem. This is in a 1971 IH cabover semi tractor. My problem is that the slotted screws that hold down the crossover tubes are stuck. I haven't twisted off the screw heads yet. But they arent budging at all. I tried PB Blaster, then acetone and atf mixed together. Tried tapping on the screws with a screwdriver with a through shank. I rapped on them pretty hard. Ive been doing this on and off for two days, 3-4 times per day. I also put a little heat on them with a propane torch. Nothing. These were likely removed and replaced 25 years ago or so as the center head was replaced before I bought it 17 years ago. The engine runs fine. But the rig is 53 years old. Any suggestions? If these wont come out, do i chisel off the screw heads and drill out the screws and re-tap? Or is there a better solution? Like a hold down bracket.
Buy a Simple Hammer driven Impact tool, 3/8” drive and a couple slotted screw driver impact bits. 12-16oz ball peen and a few slaps they will turn out. Have owned one of these since owned motorcycles, required for those fasteners.
Same here, hand held impact driver, I've had that happen & the driver has always done the job.
That’s the way I got mine out as well.
The hand held impact driver did the trick. I had a very small hole rusted through one tube. It took multiple sessions with the impact driver and more acetone mixed with atf. But all 4 screws are out. They were really stuck. I am amazed that none of them snapped off. Even after they started moving it was more fluid and back and forth with a screw driver to get them out. I bought a Quinn brand driver from Harbor Freight. I had an old driver but the straight bit was broken. The Quinn driver was pricy at $40 but it has a lifetime guarantee. They said, break a bit and you get a new one. It came with two long straight bits. I first used the smaller one and in 5 hits, the tip broke. The slightly larger one barely fit into the slots but it did not break. So I need a new crossover. Should I go to Cummins and get one? There are several being sold on the web. What about O rings? The rings are still there and intact, but after this many years it seems silly to not replace them. Are those generic O rings? Finally, the screws. I have beat these 4 to death. What if I put in allen head socket head cap screws and washers? Or should I go to Cummins and get their replacements? I'm going to try and get the other crossover out as well. Its rusty as well. I'll clean everything and paint them when I am done to avoid more corrosion. Thanks everyone!
I used the impact hammer on the other crossover screws and the last one broke off below the surface of the head an 1/8" or so. These appear to be just 1/4-20 threaded screws and they seem to measure 7/16" long, so I guess I have a "drill it out and retap it" challenge. I think I will need to pull off the rear aluminum rocker box to do this. Or is there a clever way to get around this repair. At least the other three came out cleanly. I'm amazed that the screws on the other crossover did not snap off like this last one.
I bought a crossover kit from Dependable Diesel in Arizona. About $108 for everything, screws, o-rings, crossovers.