2005 GMC C8500 Caterpillar C7 cooling system filter

[Ncostello]

Would a 2005 GMC C8500 cat C7 engine have a coolant filter? It came OEM with long life cat red coolant. And the truck only has 5000 miles on it (fire tanker) so it's time for a coolant change. But unlike everything else we have there is no visible coolant filter anywhere. Seems odd to me.



Local CAT dealer said some C7's do depending on the OEM. I called a former GMC Medium/Heavy dealer and since GM quit making them they seem to have forgotten everything there was to know about the trucks. They only supply parts nowadays.



Looked like some sort of housing on the driver side with a coolant hose coming off of it. Kinda like an upside down old style cartridge style filter housing. I hope thats just an elbow adapter for the OEM's depending on the direction they want the hose to go cause it looks like a bear to get to if it's a coolant filter. CAT dealer couldn't identify the part I was talking about.

 

[Wingate]

L/S of engine, bolted to the back side of the front housing? of so, DO NOT TRY TO TAKE IT OFF!. If its what I think you are describing, its actually part of the HPOP. A picture would be great.

Anyway, if it has Cat ELC, you do not run the Cat Coolant Conditioner Filter with ELC. If you would like to run a filter, just use the Baldwin filter, (no coolant conditioner)

 

[Wayne M.]

Ya, left side top near the final fuel filter upside down? I know the 3126 better, but if it's the same- HANDS OFF! I think that engine has liners. If it does, then it has a coolant filter. If not, it should.

 

[Ncostello]

I don't think this is part of the high pressure oil system. It has about a 1. 5" coolant type hose coming off it with a worm gear. And it's a black plastic housing. Surely this can't be an HPOP item.



This round part is driver side (left) middle of block, midway between top and bottom of block. Has what appears to be one bolt holding it down... thru the center down to the yellow base it sits on I'd say. Like a filter housing. Probably has an oring around the base of it against the yellow base. There are no other spin on coolant filters anywhere. So I figured if there was one on here it might be inside this housing.



If there is no filter inside it... I guess its a "rotatable" elbow fitting that can go in multiple directions for different OEM's mabe. Just guessing.



This is the best pic I could get. This thing is back in there. If I do have to remove it... it'll be a challenge and require all of my long arms and mostly working by feel.

 

[Ncostello]

And yes, it came factory with Caterpillar red ELC. Our other Cummins trucks have Fleetguard Optimax Red ELC so I'm familiar with non-chemical coolant filter needs on such setups.



This is not bolted to the back of the front cover. The yellow base this black part sits on is bolted directly to the side of the block... perhaps tied into the cooling system.



By the same token I still am not certain coolant even goes thru this... I'm still guessing at this point.

 

[Wingate]

thats the crankcase breather and down tube

 

[Wingate]

There should be various points on the r/s of the engine near the H2O pump to install a coolant filter setup.

Try 123-0794 Coolant filter Gp.

I found this on an industrial 3126B with a serial # BEJ prefix. I believe the mounting and plumbing is the same.

 

[mwilson]

As Wertles said, it is the breather.

 

[mwilson]

Used a C7 in a Freightliner for this coolant filter group. It lays down as you can see. If you need them I can post part numbers to go with the illustration.

 

[Ncostello]

I don't believe I have a coolant filter. It's definately not as shown in the illustration. There are no external filters on this engine but for the fuel filter and oil filter. We've looked everywhere. But thanks for all the help guys!

 

[Ncostello]

To finalize my worry... is it safe to assume that if I cannot find an externally visible, spin-on (or otherwise) filter... that no filter would be hidden inside the engine itself in a cartridge style housing? I think I'm safe to assume that any coolant filter would have to have been mounted external to the engine and in a location thats possible to find somewhere.

 

[mwilson]

To finalize my worry... is it safe to assume that if I cannot find an externally visible, spin-on (or otherwise) filter... that no filter would be hidden inside the engine itself in a cartridge style housing? I think I'm safe to assume that any coolant filter would have to have been mounted external to the engine and in a location thats possible to find somewhere.

You're all set. If there was a coolant filter it would be an external mount spin-on style and would be located on the block as illustrated above or on a foward part of either the left or right hand frame rail.



They try to mount them close to the water pump to simplify the plumbing.



Mike.

 

[mweiman]

I have had a couple C7's out and stripped down to have sleeves put in. I have never come across any form of coolant filter on one. They do not have liners in them. Not sure if there was a design or material change but we had a bunch of them break the top piston ring. Haven't had any trouble for a while, knock on wood. Also if it is a rubber type crankshaft damper be sure to check it for wobbling on a regular basis.

 

[Wingate]

yeah you dont have a coolant filter. I would just use the cat cooling systme flush , get the system cleaned out thoroughly, re-fill with some fresh ELC and you should be good to go.