Hi,

In process of servicing Cooling System, hoses, etc.

I Need to replace seal on a GOOD Thermostat. Found one (1), a with Cummins rebrand for nearly $10.  

It's an O-Ring with grooved ID.

Cummins # 3942454 Seal, D-Ring

Anyone know of a better deal?  Or a X-Reference. 

Thanks.

 

Leaky

 

I used one from a Volvo thermostat the other day when I was flushing my cooling system.  I bought a bag of them from one of my suppliers for about $1 each.  If you want to try one I'll mail it to you.  

Have you checked rockauto 

5 hours ago, IBMobile said:

I used one from a Volvo thermostat the other day when I was flushing my cooling system.  I bought a bag of them from one of my suppliers for about $1 each.  If you want to try one I'll mail it to you.  

 

You dont happen to have a part number or maybe year of Volvo for these?

Long time Cummins place moved and now 20 miles south of me.  Volvo dealer is only about 8 miles.  

Thanks

015point9,

Nothing found on Rock Auto.  I thought the Felpro 35639 might work, but closer examination of it at AZ proved wrong. It's way too thick.

Leaky

The 35703 should work, from Napa.

https://www.napaonline.com/en/search?text=thermostat&q=N%3D5002000%2B5002200%2B200220100%2B10200100%2B402203300%2B599999900%2B2500010%2B2802476%26Nty%3D1%26Ntt%3Dthermostat%26Ntk%3DKeyword&isApplication=true&indices=API

 

On ‎10‎/‎2‎/‎2018 at 4:41 AM, NIsaacs said:

The 35703 should work, from Napa.

https://www.napaonline.com/en/search?text=thermostat&q=N%3D5002000%2B5002200%2B200220100%2B10200100%2B402203300%2B599999900%2B2500010%2B2802476%26Nty%3D1%26Ntt%3Dthermostat%26Ntk%3DKeyword&isApplication=true&indices=API

 

Thanks for tip. And I am correct in saying NO other sealant is needed between the Engine Block and Thermostat housing?  

Nope. The gasket/oring is all you need.

15 hours ago, Leaky88 said:

And I am correct in saying NO other sealant is needed between the Engine Block and Thermostat housing?

 

Absolutely no sealants to be used. Use a bit of anti-seize on the bolt and only use a nut driver to tighten the 3 bolts. remember those are tiny bolts and don't require a large amount of torque. The rubber seal does the task of sealing the metal to metal contact. Just need enough torque so the bolt doesn't back out.

Edited October 5, 20186 yr by Mopar1973Man

Thanks guys.  

Leaky

14 hours ago, Mopar1973Man said:

 

Absolutely no sealants to be used. Use a bit of anti-seize on the bolt and only use a nut driver to tighten the 3 bolts. remember those are tiny bolts and don't require a large amount of torque. The rubber seal does the task of sealing the metal to metal contact. Just need enough torque so the bolt doesn't back out.

 

Yes bolts break very easy...and local dealer was $9.00 for one bolt.  And they couldnt find rubber o ring gasket.  Looked closely at what I had and went with old o ring  No problems yet.  Spec torque in book somewhere, and can't remember for sure but 12 inch pounds not foot pounds sticks in my mind.  But confirm in manual.   And throw away my harbor freight torque wrench after that.  My fishing scale and bit of rope on a box end wrench took place of 1/4 inch HF  torque wrench.  

Lessons learned:

 

The NAPA seal listed above is perfect fit. 

 

Believing it was a re-branded Felpro 35703 I got one from AZ because my small NAPA store would have to order it.   

 

Felpro 35703 package says: "Thermostat Seal DODGE TK 6, 5.9L Turbo Diesel 2001-03." (Note: My truck is a 99)

 

Before receiving the info on the NAPA Seal, I had been to Auto zone with my old seal, but everything they showed was a no-go.

All the AZ DB showed was a stepped-rubber ring (square-cut) and a paper gasket. No O-ring.

 

Plug for NAPA:

[One thing I love about NAPA is they usually have assortments of O-rings in a tray where you can physically look and see what might be a good substitute.]  

 

AGAIN, I appreciate all the info and help I got from this forum.

 

Leaky

 

 

1 hour ago, Leaky88 said:

 

Felpro 35703 package says: "Thermostat Seal DODGE TK 6, 5.9L Turbo Diesel 2001-03." (Note: My truck is a 99)

I was wondering about that but for some reason I didn't say anything. Looking at the picture of a seal there was nothing on RockAuto for a 99 but 00-02 did show it, but the number is 35639, the number you posted is for 03 and up

26 minutes ago, Dieselfuture said:

I was wondering about that but for some reason I didn't say anything. Looking at the picture of a seal there was nothing on RockAuto for a 99 but 00-02 did show it, but the number is 35639, the number you posted is for 03 and up

Dieselfuture,

I had the Felpro 35639 physically in my hand from AZ.  I returned it because it is DOES NOT fit.   It is a square-cut and too thick. It has 2 different size lips on it.  (I should have taken a picture.)

 

My quote "Thermostat Seal DODGE TK 6, 5.9L Turbo Diesel 2001-03." came directly off the Felpro 35703 packaging.  

The Felpro 35639 fits like a glove on the OEM 58MM Thermostat and the OD of Thermostat with Felpro 35703 installed is exactly what the it was with the old seal installed.  And it is round, NOT square cut.  

 

I don't know why there are so many differences between the websites etc.  It could be that the Felpro 35639 I have has China stamped on it.  Who knows? ( I often buy from Rock Auto and have had good luck with them.)  

 

I even looked at an aftermarket Murray Thermostat from O'reily's and it has a thicker Square cut seal that is nothing like the OEM.  

 

 

I'm just trying to share my tiring experience in traveling down this endless gravel road.  

 

 

The 35639 appears to fit the '94-98 12 valve.

 

https://www.genosgarage.com/product/gates-33888-kit/thermostat

https://www.genosgarage.com/product/gates-33888-kit/thermostat

 

Using the picture in the link for an "example" only, the gasket on right is what the Felpro 35639 looked like.  Nothing like the OEM Seal on my "99". 

 

Since I change thermostats every coolant change it just way simpler to just get a fresh thermostat with a seal already than look for a replacement seal. 

I kept a couple old ones just in case. Used one them a while and it worked fine.

Point taken.  

 

For what it's worth, I looked at replacements - ones that I would trust- cost from $29 - $44 out the door. Two replacements I looked at did not have the same type seal which concerned me. (I'm sure a Chinese Engineer took it's compression into account, but I was not sure.) MHO, a Thermostat will either work on not.  Naturally, no Cab heat or an overheating condition warrants an IMMEDIATE replacement. The one in my truck was an OEM from Cummins.  I tested it, it passed, and elected to go with it.  I guess if you are there, and have the money, replacing it is the way to go.

 

Subject change:

Mikes article on coolant change, states system takes 6 gallons, and 1 gallon of water is usually left in the block. 

Question: Does the 6 gallon total include the 1 gallon that goes into the reservoir?  

 

Thanks.

Leaky

 

 

Old NAPA vs New NAPA... Still the same part number 375-190 or 375-180. I'm currently running the 180*F version as a test.