Overheating question

[KWKloeber]

• disconnect the heater hose to the thermostat
• take the cap off the reservoir.
• I have a small PAR hand pump the I put into the disconnected hose and pump the coolant into the reservoir until I get a steady stream of coolant.

Ron

I am interested in your method -- it may work better on the C-30 mk-1 than "our" method.  The mk-I has some unique challenges.

You pump into the heater hose (i.e., to the water heater)?
Which "reservoir cap" do you remove -- the exhaust manifold cap or the overflow tank cap?
What do you mean then "pump to the reservoir"? (keep pumping to the water heater?)
Where are you looking for the steady stream -- Out the Tstat nipple?

Thx
Ken

[Jon W]

Hi Ken, wrote the following knowing folks of varying levels of experience use this forum. Not trying to be a wise guy. Except for the ball valve on the thermostat housing, I learned this method from Ron Hill, so credit goes to him.

The set up is a Par hand pump, and a short piece of (1/2" id I think) clear hose open on one end and reduced down to a hose barb to fit the water heater loop hose connected to the thermostat housing on the other end. Optional is a second short section of clear (1/2"id I think) hose to fit onto the discharge end of the Par hand pump. I found this piece of hose is not really needed.

Remove the coolant reservoir/tank "radiator" pressure cap. This is not the overflow tank.

Disconnect the hose in the water heater loop from the thermostat housing, and plug the hose barb into it. Connect the open end of the clear hose to the suction end of the Par hand pump. Optional add a short section of clear hose to the discharge end of the Par hand pump.

Put the discharge end of the pump into the coolant reservoir/tank (not the overflow tank). Begin hand pumping and you will draw coolant through the system and back into the reservoir/tank. Continue pumping until the stream of fluid into the reservoir/tank is a clear solid color indicating no air in the coolant loop. Reconnect the water heater loop hose to the thermostat housing, being careful not to loose any coolant. Put the "radiator" cap back on.

Start the engine and watch that the temperature stays in normal range. A simple no mess bleed/burp method.

I also replaced the OEM valve on the top of the thermostat housing with a ball valve. My final bleed step is to connect a clear 1/4" tube to the ball valve and tape it to the hand hold near the top of the companionway. Surprisingly the fluid will climb that high. With the engine running I open the ball valve. The coolant begins to fill the hose and remaining air bubbles in the system percolate out. When the air bubbles stop or slow to almost nothing, I close the ball valve.

FWIW - If the Par hand pump has been sitting a while, put some o-ring lubricant on the shaft and the internal rubber pump plunger. Otherwise the pump may be "sticky" and not operate smoothly.

[Ron Hill]

Jon : You are right ON!!  I wrote this up in the Mainsheet tech notes many years ago. I've done it for many years.
Ken : All you are doing is pumping a closed loop of internal coolant thru the water heater system to get any air out!!

A thought

[KWKloeber]

Hey Jon/Ron

THANKS!  Got it.  What threw me was that I was envisioning Ron using the PAR to pump from a jug of 50-50 INTO/through the closed system.  That method will work well for the issues on my mk-I -- the WH is high (in the cockpit sail locker) and that's where air in the closed system ends up.

So the PAR procedure sucks coolant from the closed system pump, thru the WH and depends on gravity for coolant to flow from the Exh Manifold, through the Hx, block, and back to the TSTat. 

Since Brian's issue was that the airlock was located in the pump, have you ever found that the PAR method won't draw well on a recently drained/filled system because it can't pull from an empty pump? (yes I know that the recommendation is to fill the pump.) 

Just asking, do you think that it would be effective to turn the PAR around and suck FROM the Exh Manifold and PUSH it through the WH?   That would be using the PAR to push coolant into the pump.

[Noah]

Ken- the water heaters in the C34 are located under the galley sink just above the floorboards.

[Ron Hill]

Guys : I believe that the way that Jon and I suck the internal coolant thru the water Heater is the best way to get all of the air out after a coolant change.

One other thing that I do is - Every couple of years I add some "Water Pump Lubricant" to the system!!

A thought 

[Jon W]

Hi Ken. In response to your question about draining and refilling, I just removed my HX. To do that I drained the coolant reservoir, and drained the coolant from the HX. Just shy of a gallon coolant in total, so think the block, coolant pump, and thermostat housing were empty. After replacing the HX, I filled the reservoir, then began pumping as described above. Added more coolant into the reservoir to top off. Put the "radiator" cap on, and started the engine. Ran for about 20 minutes in the slip and temperature stayed in the normal range. I plan to take the boat out and motor around for about an hour next week to put the system under load to verify all is good. Hope that answers your question.

[KWKloeber]

Jon

"Yes."  Thanks!

[KWKloeber]

Ken- the water heaters in the C34 are located under the galley sink just above the floorboards.

Yep I know that

[Analgesic]

Hi again.  Alas, my problem isn't over unfortunately.  I had no problem motoring home about 3 miles from the fireworks last week, engine temp stable at 140, so I figured problem was solved.  Yesterday visiting the boat for the first time since, I again saw coolant in the bilge and the manifold ( if that's the right name) where it gets poured in was visually down about a third while the overflow container was half full where it usually is.  I couldn't identify any leaks.  A friend told me I might get a pressure tester on loan from an auto parts store-says you place it where the radiator cap goes, pump up the pressure and reveal the leak site hopefully.  Does this sound right/possible?  I'm not sure how old the hoses are going from the engine to the WH but the first crack I saw last week was right at one of the WH nipples and I cut off the bad area, shortened it by an inch and seemed to get a good seal when I replaced it with no weeping from that site now.    I am supposed to leave on my one month trip to Maine in 10 days so I'm feeling the pressure.  I could replace all these hoses which won't be fun and will be time consuming.  There's a lot of hose out of site under the floor and I guess there's no other way to know if there is hidden trouble. If there's a better first step, I'm all ears.  Does coolant ever leak from the WH itself?  It's mounted on a plywood platform and not even sure how I would find out.  The platform has lost its ? epoxy seal to the hull so there could be a little movement in rough conditions of the WH but with all the attached hoses and the low almost midline location, I don't think it can move too much.  Thanks again for any guidance.  Brian

[KWKloeber]

Questions

Have you downloaded and read the parts manual for your engine? - It really helps when identifying engine parts.

Have you studied the coolant flow diagram (it shows seawater and closed)  - it can help to ID every place that a hose connection could be loose.

What's your annual PM on the cooling systems on the engine?

****

If you post good pics of your engine it can often help to ID issues. 
Help US to help YOU.

***

Coolant could be theoretically leaking from anywhere there is coolant, including if there (unlikely) a hole in the WH.

Coolant can be lost if there is a pinhole leak between the seawater and coolant sides of the Hx, although it should not show up in the bilge.

Coolant can also be lost if there is a pinhole leak between the potable HW vessel and coolant ("heatant") loop in the WH. It would depend on the relative pressures which way each fluid would be pushed. Obviously it would not be good, as (there is a very slight chance that) toxic coolant could be pushed into the potable water supply.

[Jim Hardesty]

A friend told me I might get a pressure tester on loan from an auto parts store-says you place it where the radiator cap goes, pump up the pressure and reveal the leak site hopefully.  Does this sound right/possible?

It's good trouble shooting.  Much better than guessing at what to change.
Jim

[Jon W]

Would you guess the amount of coolant in the bilge was about equal to the 1/3 missing from the coolant reservoir on the engine? If so, and you don't see coolant anywhere else, you're problem is most likely a leak from one or both of the hoses going to the water heater. If one hose was cracked at the WH nipple, odds are it's time to replace both hoses.

[Analgesic]

I agree the bilge amount seems about equal to the loss.  I'll attack the hose replacement first thing tomorrow morning.  My usual auto parts store doesn't have the radiator cap pressure tester to loan/rent.

[Ron Hill]

Brian : Take a paper towel and wipe each of the hose connections and see if you can find the one that is leaking.  Then you can change out the hoses that go under the galley floor.     
 
A few thoughts