Coolant reservoir possibly clogged

[buddybear]

This is a Universal 25XPB engine. Had a problem with the overflow tank not working properly. The coolant would not go back into the reservoir. I finally lost all of the coolant from a leak I am still searching for. The coolant in the overflow tank still was not going into the reservoir. I took the elbow off of the reservoir and found it to be completely clogged, also the hole which it threads into was clogged. I cleaned out the elbow and tried to clean out the hole in the reservoir it threads into. I finally decided to drill into the hole to clean it out. I was starting to get metal shavings when I was drilling and stopped. Does anyone know if that hole goes all the way through or if there is a channel below the hole which lets the coolant into the overflow tank? I don't want to drill a hole where it doesn't belong.

Thanks,
Mark

 

[buddybear]

This is a Universal 25XPB engine. Had a problem with the overflow tank not working properly. The coolant would not go back into the reservoir. I finally lost all of the coolant from a leak I am still searching for. The coolant in the overflow tank still was not going into the reservoir. I took the elbow off of the reservoir and found it to be completely clogged, also the hole which it threads into was clogged. I cleaned out the elbow and tried to clean out the hole in the reservoir it threads into. I finally decided to drill into the hole to clean it out. I was starting to get metal shavings when I was drilling and stopped. Does anyone know if that hole goes all the way through or if there is a channel below the hole which lets the coolant into the overflow tank? I don't want to drill a hole where it doesn't belong.

View attachment 213449


Thanks,
Mark

What I am calling the reservoir is actually the manifold which holds the antifreeze.

 

[Tally Ho]

I think you mean the heat exchanger.

Hard to tell from your photos where you are drilling…On my Yanmar, the overflow is up near the fill nozzle.

if you are getting shavings, I would stop. You don’t want to ruin the HX.

Greg

 

[Richard19068]

That's not a great picture of the problem but I'm glad you stopped drilling when you started to get metal shavings!

I assume you are talking about the elbow and passage through the exhaust manifold filler neck (part 1 in the attached parts pdf).


I don't know the answer to your question about a "channel below the hole" but assuming you are talking about the hole in the filler neck did you try to clean it out with a flexible wire like a pipe cleaner or similar?


Is your pressure cap in good shape?

 

[buddybear]

That's not a great picture of the problem but I'm glad you stopped drilling when you started to get metal shavings!

I assume you are talking about the elbow and passage through the exhaust manifold filler neck (part 1 in the attached parts pdf).


I don't know the answer to your question about a "channel below the hole" but assuming you are talking about the hole in the filler neck did you try to clean it out with a flexible wire like a pipe cleaner or similar?


Is your pressure cap in good shape?

I cleaned the elbow which screws into the manifold and connects to the hose to the overflow tank. I am attaching another picture to help me understand how the antifreeze can go from the manifold to the overflow tank. It must not work on gravity. The hole in the manifold which the elbow threads into does not open into the manifold where the coolant is I thought it was clogged but with a drill I got metal shavings. This is my big question is there supposed to be a hole there?

 

[Richard19068]

...to help me understand how the antifreeze can go from the manifold to the overflow tank. It must not work on gravity. .. This is my big question is there supposed to be a hole there?View attachment 213461

I don't know specifically how your engine works but typically when the coolant heats up it expands and is forced up the hose to the recovery tank. It's usually regulated by a valve in the pressure cap which doesn't open until the manifold gets up to a certain pressure. When the engine cools the coolant contracts and creates a vacuum in the manifold and is sucked back into the manifold. Again regulated by the pressure cap.

I can't clearly see in your pictures where the elbow is screwed into the manifold. On my engine (Universal M18) the hose to/from the recovery tank goes to a nipple in the throat between the pressure cap and the manifold. I would certainly think there should be a clear passage between the elbow and inside of the manifold. Did you look at the prior attachment for exhaust manifold service where it shows "clear this passage"?

Can you post a picture that clearly shows where the elbow screws into the manifold?

Here's an article that talks about how coolant recovery systems work

Know Your Coolant Recovery Tank System | Cruising World

You may not fully comprehend their significance, but coolant recovery bottles are the unsung heroes of the engine compartment.

www.cruisingworld.com

 

[john2]

the elbow should be open, it comes out in between the fillercap. from inside the fillercap should be the connecting hole.
check the lower valve in the fillercap that it not sticking te the rubber seal. if the motor overheated with a faulty fillercap the coolant pressure can go to high.... And it will find another way out of the engine. check the waterpomp seal and even your freeze caps on the engine. this means fill the coolant system and watch it warm up and check for leaks.

 

[buddybear]

the elbow should be open, it comes out in between the fillercap. from inside the fillercap should be the connecting hole.
check the lower valve in the fillercap that it not sticking te the rubber seal. if the motor overheated with a faulty fillercap the coolant pressure can go to high.... And it will find another way out of the engine. check the waterpomp seal and even your freeze caps on the engine. this means fill the coolant system and watch it warm up and check for leaks.

Thanks for everyone's replies. I didn't realize that the hole is actually in the filler neck, I either made a new hold with all of my digging or cleaned out the old one. Antifreeze will flow back from the overflow tank into the manifold. I ran the engine for about 40 minutes at the dock the temp went to 170 degrees and stayed. I am now going to clean everything up and see if I still have a leak.

Thanks Again,
Mark