Cummins 6CTA collapsed hose

While changing my oil I noticed one of my coolant hoses off the heat exchanger was collapsed while not running. Once the engine warmed up after several minutes, and I assume the coolant warmed, the hose went to it's normal shape. It is really cold out and I might not think much of it if the other engines hose weren't completely normal in shape under all conditions. This seems like a vacuum issue to me somewhere. Anyone else have this problem and solved it, or is it a non issue? Maybe a faulty check valve on the radiator cap?

Sorry I can't seem to rotate the photo on my phone.

I have the exact thing happen on both 480 CE's. A mechanic told me not to worry about it. I even released the pressure by opening the cap and it reoccurred. Temps are good and no leaks, so I don't worry about it any more. I did replace the coolant and all hoses 2 years ago.

Yep, sounds like a bad rad. cap. The cooling system should pull coolant back in from the reservoir as it cools.

It's a non issue. You have a little air in your cooling system. It'll work its way out

Thx. I may replace the cap just in case. It looks original while the other engine has a newer cap on it. Albeit the problem side is a recon engine that is only 4 years old.

If it looks original, a new cap certainly wont hurt.
Also, that hose looks a little too soft (worn). depending on how it feels, might be time for a new one.

My port side does this. I've put a new cap on and new hose. It still does it.

Same thing on my port motor as well. 2 Cummins techs told me it was normal.

It’s normal. Make sure you don’t have air in the line and new caps but it is normal.

Thx all. It's my stbd side fyi. I did however notice my heat exchanger is running quite a bit warmer on my port side. I was planning aftercooler service this off season but the heat exchanger will need to be done too.

This also happens on my port engine, Cummins tech also said it’s nothing to worry about. Odd ways this is so common on the port engines.

I did a complete "re-hosing", coolant and aftercooler re-furb last year. I did it myself. 800hrs on both engines. Took some time and followed Seaboard (aka Tony's) advice. A couple tricks I only learned after the first one, but all's well. I did not pull the exchangers but reemed them in place, using rifle cleaning tools. I did wish I replaced the thermostats' at the same time, but no issues none-the-less. Hoses still collapse. Let me know if anyone wants some help with that. Saved $$$$.

Islandtime04 said:

I did a complete "re-hosing", coolant and aftercooler re-furb last year. I did it myself. 800hrs on both engines. Took some time and followed Seaboard (aka Tony's) advice. A couple tricks I only learned after the first one, but all's well. I did not pull the exchangers but reemed them in place, using rifle cleaning tools. I did wish I replaced the thermostats' at the same time, but no issues none-the-less. Hoses still collapse. Let me know if anyone wants some help with that. Saved $$$$.

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I have read many articles and watched Tony's video, it looks pretty cut and dry. I'll start on the stbd aftercooler as it is much more accessible. If you have any tips and tricks that you learned along the way do let us all know. Thanks.

several things:
1- Get the refurb kit (gaskets and grease) from Seaboard. Read and watch tony's video.
2- very little water comes out of the hoses when you remove them...that was a surprise to me.
3 - big lesson learned. After you remove the end caps and BEFORE you remove the core, clean (brush and brake cleaner) thoroughly around the core bottom/edges (where the core meets the housing) really good. Use light sandpaper too and even a soft pick (e.g. wooden skewer) around the core edges. there is some light corrosion there and tolerances are tight. cleaning it gets rid of the crud and really helps the core to slide out. I used a 2x4 and rubber mallet to get it started. It's all brass and soft...so be gentle.
4 - Inspect the core really good. The condition of the fins will tell you a lot about what's going on and frequency of next cleaning.
5 - Use a .22 rifle cleaning rod with brass brush to clean the tubes. I've had others warn me that this may be too rough. but the brass bristles are soft and do a good job. just be sure to ram it all the way through before pulling it back out, and do each tube only once. Also, get various grit sandpaper to clean the ends. I ended with 220. Cleanness is next to godliness and you must not F with the tolerances. Lots of brake fluid, 220 sandpaper and brass wire bristle. don't be to aggressive. when done, rinse with water and let dry completely before reinstall.
6 - lesson learned. Apply the grease AFTER you reinstall the core. it prevents the grease from getting all over the cooling fins. just slide the core back and forth after install...again that will make sense when you do it.
7 - I asked tony what to do with the rubber strips on the side of the core (it will make sense after you remove the core)..he told me to throw them a way. I did question this advice, but I trust him. So I did, and temps are solid at 165-168 at cruising speed.
8 - lesson learned. line the fins up correctly before reinstalling in housing. mark the bottom of core with marker to ensure they are lined up after install.
9 - Install new zincs before reinstalling.
10 - With the aftercooler and air cleaners off, it gave me good access to the cooling hoses..so I replaced those. Again buying form Seaboard. I also painted them Cummins white before final installation for a finished look.

It looks intimidating at first...but actually pretty easy if you have any mechanical skills. Its very rewarding and huge money saver. Good luck and pray for a short winter!

Islandtime...nice write up. I did mine in Fall 2018. I removed the components and cleaned at home on a bench. I sent the Heat Exchanger out to a radiator shop for cleaning and pressure checking. After putting the after-cooler back together, I had the same radiator shop pressure test the after-cooler. I just wanted to make sure that the O-rings were seated properly.

To your point #7, the plastic/rubber strips tend to want to come off after cleaning the core in brake fluid. Just remove them as you said.

I went ahead and changed the T-stats while we were there. You need to drain a bit of coolant out to lower the level.

Jaybeaux

Jaybeaux said:

Islandtime...nice write up. I did mine in Fall 2018. I removed the components and cleaned at home on a bench. I sent the Heat Exchanger out to a radiator shop for cleaning and pressure checking. After putting the after-cooler back together, I had the same radiator shop pressure test the after-cooler. I just wanted to make sure that the O-rings were seated properly.

To your point #7, the plastic/rubber strips tend to want to come off after cleaning the core in brake fluid. Just remove them as you said.

I went ahead and changed the T-stats while we were there. You need to drain a bit of coolant out to lower the level.

Jaybeaux

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Good call on the pressure testing...peace of mind is worth a lot.

this is on my todo list in the next few weeks. Really dreading port motor though. Any tricks there? Assuming you need to get comfy and law across the motor and removing the starboard one first would help with the learning curve.

N

Irie308 said:

this is on my todo list in the next few weeks. Really dreading port motor though. Any tricks there? Assuming you need to get comfy and law across the motor and removing the starboard one first would help with the learning curve.

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not really and not as bad as you think. Once you remove the air cleaner and 2 hoses, it comes off easy. I do remember there was some decision on how to remove it, either from the bracket or with the bracket...but you can figure that one out.

Send me a private email if you want to work through the details. Yeah, good idea to remove the starboard one first...and learn from that.

Irie308 said:

this is on my todo list in the next few weeks. Really dreading port motor though. Any tricks there? Assuming you need to get comfy and law across the motor and removing the starboard one first would help with the learning curve.

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Something that I find helps out when reinstalling the aftercooler is a short piece of all thread or a bolt with the head cut off to thread into the aftercooler in one of the three top bracket holes. It’ll allow you to hang the a/c on the bracket while you start all the rest of the bolts. It beats trying to hold it up with one hand while trying to start a bolt with the other while leaning over the top of the motor.