dang plastic coolant tank replacement

[kb7uxe]

Hello from Dan..
Our 2008 Monaco 5.9L dressed as a 6.7, had the plastic coolant tank. and, I thought it broke, but it was just the bottom hose leaking. so, I know they are prone to failure and I decided to replace it. what I found was, the replacement tank is about $500 ouch !. But in searching I found that the Peterbilt 320 series uses a round steel tank with the same connections. and with minimal modification just about fits right in. I ordered mine from a wrecking yard, and it cam with brackets, cap, water level sensor. 1st I enlarged the access port. and removed the old tank. That required removing the entire air filter housing from the side panel driver side behind the tire. once the Air filter housing was removed, it came right out. the metal that the bottom of the original tank was mounted to I was able to drill 2 new holes to fit the new tank bracket. the upper bracket will mount to the original upper mounts. I added the 1.25 diameter x 1/2" pipe brass barb for the bottom. the upper mount needed to be lowered. I used flat bar in an X configuration to add rigidity. the water sensor even plugged right in and worked ! The 2 small upper mystery hose fitting has to be replaced with straight fittings.
Bottom line the Peterbilt 320 series tank does fit and works well for a lot less $..

[Monaco_hwy]

It looks like the plastic tank that you replaced runs with no pressurization. This is like the standard overflow tanks used in cars.

Your metal tank looks like it is intended to be run pressurized, judging from the cap on the tank. Could this be a problem?

[jacwjames]

Looks good and definitely a viable option. The old tank did run with pressure, can't remember what the radiator cap was rated for but fairly low.



Thanks for posting.





When I bought my 2002 Windsor in 2008 the tank had some hairline cracks that were weeping. I was able to patch it using polyethylene glue and that lasted another ~5 years but ultimately replaced mine with the same type made out of Nylon and so far after ~8 years still looks good.

[moisheh]

Great write up. Does the Pete tank have a sight glass? How did you ever come up with using that particular tank.
?

[moisheh]

I just noticed the plastic hose that acts as a level indicator.

[RobRoy]

Thanks for sharing.

My coach still has the pressurized plastic tank and is working fine ( for now)

Just taking some notes on this thread


FYI

Seen another 320 tank here https://www.mylittlesalesman.com/200...e-tank-9005166

and those Peterbuilt 320 tanks look like they will fit my application too.

FYI they sell like $ 600.00 new

Happy Trails

[kb7uxe]

Originally Posted by Monaco_hwy

It looks like the plastic tank that you replaced runs with no pressurization. This is like the standard overflow tanks used in cars.

Your metal tank looks like it is intended to be run pressurized, judging from the cap on the tank. Could this be a problem?

the plastic tank I removed has a 16PSI radiator cap on it, and it does run pressurized. it IS the remote radiator expansion tank. Not an overflow tank..
:-)

[kb7uxe]

Originally Posted by moisheh

Great write up. Does the Pete tank have a sight glass? How did you ever come up with using that particular tank.
?

I was searching for a replacement tank, other than spending $500... I started searching heavy rig wrecking yards on line. this one has the correct plumbing fittings, was close to the same size. it fit a Peterbilt 320 series, so I started searching for the best price that came with brackets etc.. with shipping, tax, etc it was $169..
then spent $11 for the bottom brass fitting and $8 x2 for the 2 straight barb fittings for the 2 top mystery hoses. Then, once it was installed, the low level sensor even plugged in and works !!, so I have a spare from my old tank... so for a saving $320, and a little fabrication on my part, his works. and works well.. I will see about making a better top bracket link.. I was thinking I would have to re-invent the entire main support, but as it worked out, I was able to utilize both oem brackets. So i'm pretty thankful and happy with it. :-)
As time goes, these plastic tanks will fail, and being held hostage by a $500 tank made this a challenge. so hopefully this will save someone else who is handy...
I purhased mine from
COMPLETE RECYCLING GROUP
1500 W. Pulaski Hwy
Elkton, MD 21921
United States
410-620-9800
Fax 4435933928
mdriver@complete-recycle.com
http://www.heavytruckpart.com
They were very helpful on the phone...

[kb7uxe]

I found this information on line regarding the tank size.
According to my handy dandy online volume calc,
13.5" x 7" is roughly 2.25 gallons. (horizontal with dish ends.)
The plastic tank is slightly larger 3 gallons. (rectangle ) But this does not take into account the slight slope and depressions in the plastic tank..so my guess would be actual 2.50-2.75 gal. so the metal cylinder is slightly smaller volume, but this should not be an issue. I plan to add an over flow tank just in case..

[moisheh]

A number of years ago I replaced the plastic tank in our 08 Dynasty. It was not leaking but I worried it would crack. I bought an aluminum tank from Source Engineering. Not one of their best products. It was much smaller but they assured me it met Cummins requirements. I kept getting a low coolant warning. I don't know if it had something to do with the aluminum or just the design of the tank. I reinstalled the original about 8 years ago. It is still working fine. The Dynasty uses a 3 wire sensor. Plastic. I winder how that would work on the steel tank. Is the Peterbilt sensor a 3 wire? Thanks.

[96 Wideglide]

Good for you !

Cummins used some real junk, as well as their Onan subsidiary!

They too use garbage coolant tanks !!

[jdw1]

That looks like a good alternative!

I decided to go with this one,
https://clowfabandperformance.com/pr...aco-surge-tank

Just another choice for those looking for a replacement.

[Mile Marker 42]

Originally Posted by moisheh

A number of years ago I replaced the plastic tank in our 08 Dynasty. It was not leaking but I worried it would crack. I bought an aluminum tank from Source Engineering. Not one of their best products. It was much smaller but they assured me it met Cummins requirements. I kept getting a low coolant warning. I don't know if it had something to do with the aluminum or just the design of the tank. I reinstalled the original about 8 years ago. It is still working fine. The Dynasty uses a 3 wire sensor. Plastic. I winder how that would work on the steel tank. Is the Peterbilt sensor a 3 wire? Thanks.

I've got the source tank on my rig and no problem. Strange you didn't like it. Maybe it was early production before they had all the bugs worked out? Mine uses a 2 wire ford sensor.

[moisheh]

Mile Marker. Mine was very early production. They changed the layout and size with later production. .