Ive been monitoring this leak from the rubber EGR hose for a month now. Tightened those clamps several times to the point they won't tighten anymore and the leak still persists. I had my EGR cooler checked just quickly by removing the clamp to look inside and it was dry but that was also after the truck sat for sometime. Peterbilt thought that because my VGT actuator was malfunctioning it was creating excess pressure and forcing a leak from that hose but it's been a week with my new actuator and all is well except this leak came back the other day and seems to get worse now. Is it even possible for that fluid to be moisture/oil/unburnt fuel? Or if there is fluid in that part of the system is it almost certainly coolant from the EGR cooler? It's not a massive leak so the cooler could easily dry up inside I think to give the impression it's okay but then when I drive it could start leaking again.
To make clear the origin of the leak I took this picture. It doesn't look bad cus I clean it off regularly but under that hose it is clearly leaking and then it drips and runs down the EGR and engine
What color is it? Does it smell like fuel? Are you loosing coolant? Any soot in your surge tank? 90% of the time it is indeed the egr cooler. You can usually pull the pipe and tell if it’s coolant…… BUT, egr is recirculated exhaust, so if you have a cracked head, leaking injectors, cracked liner….. etc. then it would also put that in the egr pipes ( I mostly added that to scare you) remove the cooler, buy or build a pressure tester and test it….. or let peterbuilt rail you with their prices for testing it
(02-23-2023 )Bengy88 Wrote: [ -> ]What color is it? Does it smell like fuel? Are you loosing coolant? Any soot in your surge tank? 90% of the time it is indeed the egr cooler. You can usually pull the pipe and tell if it’s coolant…… BUT, egr is recirculated exhaust, so if you have a cracked head, leaking injectors, cracked liner….. etc. then it would also put that in the egr pipes ( I mostly added that to scare you) remove the cooler, buy or build a pressure tester and test it….. or let peterbuilt rail you with their prices for testing it
Hey Bengy! It's black like oil but I'm thinking even coolant would be black after being in that tube with the exhaust and heat. It doesn't smell like fuel to me though I haven't been able to collect large amounts of liquid since it drips off slowly. I haven't noticed loss of coolant except the last 2 weeks it's been drained by 2 different shops and both times I had to add more after so I just assumed some was lost. Ive had that pipe by the cooler pulled off twice to check for leaks and both times it's been dry but also the truck had sat for a couple days and maybe it only leaks when I drive and then evaporates. Is it possible to be oil or even just moisture? I don't want fluid in my EGR system messing it up though or going back into my cylinders probably
Are you having to add coolant regularly to the engine to keep it topped off?.
Your next move would be to remove that pipe off the back of the egr cooler, and put a small catch-pan under the back of the cooler. Then to pressurize the coolant system over night with 20 psi of pressure on it .. look to se if coolant is pooling up in the catch pan.
Here is an example of this same test that was done to an older model engine ...
(02-23-2023 )Rawze Wrote: [ -> ]Are you having to add coolant regularly to the engine to keep it topped off?.
...
Its hard to say if I'm losing coolant because in the last 2 weeks I had it drained twice and each time after I had to add more but I thought that was because some was lost during the transfer. Before that I wasn't losing much coolant but I'm going to monitor it closely this week. I was just at Peterbilt and they took the back of that pipe off to look inside and I seen it was totally dry and free of build up in that pipe directly after the cooler. I will try the PSI test when I get a chance though I will have to find a cap that can attach to a pump like that to do it. I'm starting to think it's not coolant because that pipe should have been a mess if it was but it was clean and dry. Yet something is still leaking from the top hose. I don't think it's simply moisture because it was -13C this morning and that fluid wasn't frozen. It also doesn't smell like diesel though. I washed the engine and am going to monitor it closely for other leaks
(02-24-2023 )Cartman Wrote: [ -> ]I had the same sorta exh leak on my 871 just not as sooty wet looking, replaced the hose and better clamps PN 2882472
Looking at the photos does it seem the oil leaks and egr leak are unrelated to each other?
You were right I found one of the bolts in the corner of the valve cover is leaking oil and running down a piece of metal above the EGR hose and dripping down the back side of it. Seeing the exhaust leak I just assumed it was all related but whatever that exhaust leak was it's dried up and the inside of my EGR hose is dry and clean too. I washed the engine which allowed me to see it wasn't actually originating from that hose. Strange that oil would be making its way through one of those top bolts though. It's not very much but enough to fill up that cavity in the valve cover that the bolt goes into within a day and then drip down. Is that entire valve compartment filled with oil under pressure when the engine is running that it would be seeping out the top like that?
Is your crank case filter a maintenance free one?... if not then it might need to be changed..,as it can cause a lot of oil leaks on the engine as crank case fumes build up.