Coolant Leak

[MangoMike]

I found a small pool of coolant beneath the coach this morning as I was polishing my slack adjusters.

Looks like it's coming from this:

2053

2054

I'm assuming this is the water pump.

The bottom of the blue hose going to the coolant filter/conditioner was very wet. Though I think the hose was just the conduit for the leak and not actually leaking. Does the gasket between the pump and the engine have a history of leaking? Or could it possibly be the hose?

Thanks
Mike

[dalej]

Mike, it sure looks like a gasket. Can you get the water up to temp and look at it? I would clean the area first and then start the engine and wait till you see a drip. I'm glad to see you only have these little maintance issues, you know the fun ones.

[MangoMike]

Dale,

Thanks for the heads up. Do you think I can replace the gasket without having to drain the system and remove all the hoses? Or am I just dreaming.

mm

[dalej]

I kind'a think that it would be lucky if you could. I would, if it were me doing it, crack the bolts slightly to see, but be ready to retighten them. Don't undo them much, just start with half turns.

I bet it will remain tight untill the bolts are loose and you have to pry the housing a little, then its to late. So I guess, be safe and drain it down untill coolant is below the housing. If you have the buckets then draining is just the first thing on a coolant job.

[bluevost]

MM,

The techs at Mira Loma have a pretty good system for draining coolant. Get yourself a clean wash tub, put it on casters of some kind. Drain coolant into tub, and roll out of the way while you replace gasket. A small submersible pump with a piece of hose attached pumps it right back into the system. Shouldn't spill a drop.

Ken

[Jon Wehrenberg]

The difficulty of replacing coolant is the little nooks and crannies trap air. There is a vacuum system that is sold by Snap-On. It goes where the radiator cap is, allows shop air to pull a vacuum on the system, and then with a hose attached, will suck the coolant from the big wash tub, filling those little air locks.

Mike, is the bus due to have the coolant changed anyway? I schedule stuff around those projects. If the leak merits a repair and the coolant change is near due, I would do them at the same time.

[JIM CHALOUPKA]

Nice big fiberglass water tubs at Tractor Supply.

[MangoMike]

Good advice from all.

I think the first step, a la Dale, is to fire up the engine and see if in fact the leak is from that gasket.

If so, I'll drain and be ready to replace the coolant just to be on the safe side. I understand there is red and green coolant (pretty technical talk here). Right now I'm sporting the green.

Which type should I use, and I'll change the coolant filter at the same time.

Anyone have any idea how big a job it is to change that gasket?

Thanks

Mike

[Jon Wehrenberg]

The coolant sold by Detroit Diesel, unmixed, specifically for our engines is the red stuff. I have used antifreeze that meets the DD specification purchased from a truck stop (for a lot less than DD charges) and it was green.

I have no clue if they are compatible. I use the same stuff I use in my engine in my generator.

[Ray Davis]

I have no clue if they are compatible. I use the same stuff I use in my engine in my generator.

A tech at Prevost Mira Loma told me that you definately do not mix the two types of coolant. He likened it to "crossing the streams" in Ghostbusters.

At Prevost they seem to always put in the green stuff, at least with the 8V92 engines. I haven't had coolant service with the new bus yet.

ray

[Joe Cannarozzi]

Often a small cold leak will stop when warmed up. Could just be loose too.

[dalej]

Joe, I thought it might just leak when the water was up to 200 degrees or hotter, like when he shuts down and the engine heats a little more. The pressure in the system pushes the water out.