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Topic: Coolant leak from ? (Read 543 times) previous topic - next topic

Coolant leak from ?

I have coolant leaking from a coolant line that is connected to the piece in my pictures. Not sure what it is. Hoping I can clean around the fitting, remove line and repair.

Has anyone had a similar issue with this line leaking? Does this have an o-ring or is it some type of compression fitting?
Dylan and Aimee
2001 U320 4013
Unit# 5896
450 HP/IFS
 

Re: Coolant leak from ?

Reply #1 –
Need a wider view to see what the line is going to. Compressor maybe?
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Coolant leak from ?

Reply #2 –
Quote from: craneman –
Need a wider view to see what the line is going to. Compressor maybe?
Was thinking it's the compressor, but didn't know those were water cooled.
Dylan and Aimee
2001 U320 4013
Unit# 5896
450 HP/IFS
 

Re: Coolant leak from ?

Reply #3 –
Where does the other end go?,all we see is 1 end,it may be a part numbered item,the line just above the nut may be cracked,it's a
compression fitting.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Coolant leak from ?

Reply #4 –
Whatever that line goes to, it appears to be in really rough condition.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Coolant leak from ?

Reply #5 –
I believe that is indeed the top of your air compressor.  There should be two coolant lines - one is hidden in the photos.  The link below has photos of what looks like a similar model compressor.  Note the two white plastic plugs where coolant lines connect.

3689649 | Genuine Cummins® Air Compressor Reman

If you go to the Genuine Cummins Parts page, and enter your engine ESN number, you should be able to look up the coolant line part numbers.  Then search for the part numbers online to find the best price.

Genuine Cummins Parts

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Coolant leak from ?

Reply #6 –
The top plate on that compressor looks like it is made of aluminum.  To replace the coolant tube, you may need to replace the compression fitting that is screwed into the plate.  If so, be very gentle when removing the old fitting.  You don't want to bugger up the threaded hole.

Worst case scenario, you could just replace the whole compressor top assembly.  That kit should be readily available, although it may be kinda pricy.    :o    See example below (not necessarily the correct part number):

4337592, 4089238 | Genuine Cummins® Air Compressor Head Kit

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Coolant leak from ?

Reply #7 –
Started to remove the coolant line that is connected to the compressor head. The line is deteriorated right at the compression nut, as I started loosening the nut the line gave way as you can see in the pictures.

As mentioned above I'm going to be very careful as I remove the nut and hopefully the threads in the head will be okay to install the new coolant line.

The part number for the coolant line is 3400718. I searched around on the internet hoping to find one on eBay a little bit quicker than Cummins, but no luck. There are plenty in stock at the Cummins Warehouse in Memphis so I paid for expedited shipping and they said hopefully it'll be here by Wednesday, and I'm leaving Thursday morning. So yeah cutting it close, and that's if everything goes smoothly.

I'm going to order the other coolant line also, though it's not leaking at the moment so I'm going to leave it alone until I get back from my trip.
Dylan and Aimee
2001 U320 4013
Unit# 5896
450 HP/IFS
 

Re: Coolant leak from ?

Reply #8 –
The fitting in the head looks to be in good shape, threads are fine...hopefully the coolant line slips right in and I'm good to go.  🤞

I didn't try and remove the fitting from the compressor head that the coolant line connects to because i don't think that's where it was leaking...and as mentioned before, didn't want to take a chance of buggering up the aluminum threads. The Cummins schematic also shows an o-ring in there. If it still leaks some once I replace the line, I'll pull it all apart and replace all fittings and o-rings in the compressor head when i get back.
Dylan and Aimee
2001 U320 4013
Unit# 5896
450 HP/IFS
 

Re: Coolant leak from ?

Reply #9 –
That appears to have cleaned up nicely and should be just fine.  Once in a while things are not as bad as they might look.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Coolant leak from ?

Reply #10 –
Was told part wouldn't show up until today but it came yesterday morning...Memphis to CA in 24 hours, not too bad.

No leaks so far, but that's only at idle...I'll check again tomorrow when I get on the road.
Dylan and Aimee
2001 U320 4013
Unit# 5896
450 HP/IFS
 

Re: Coolant leak from ?

Reply #11 –
Quote from: dlkj07 –
Was told part wouldn't show up until today but it came yesterday morning...Memphis to CA in 24 hours, not too bad.

We've order a lot of stuff from Cummins recently and they have been very quick to ship
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Coolant leak from ?

Reply #12 –
A little late now but I would get some black spray paint and paint before rust starts.
96 U270 BUILD 4810
85 380SL
Drummonds TN.