volvo 3.0 glp-c circulation pump hose swells and shoots off.

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thorock

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I just purchased this boat. At around 3000 rpm the the hose starts to swell and comes off. I have about 40 psi at the thermostat as well as the output of the raw sea pump. I can take off the hose to the riser with no change in the pressure. I can have the thermostat in or out with the same pressures. I have had the thermostat housing off. Looks ok but little rusted. had the circulation pump off to see if the block was full of sand but was ok. I have small bubbles going in and out of the raw pump. the vacuum reading goes from 4 to at most 9. I have done a leakdown test but every cylinder shows 20% leakage. I can hear it and feel it coming out of the pcv valve. The water level does not change when I am doing the test. I have flushed the lines. I took off the riser and found it rusted but flows with a water hose ok. I do get slag out of the manifold drain almost every time the hose pops off.
The prop looks like it has hit every thing but the lottery. I was told the engine was new with 30 hours on it. Seems to me it is a restriction somewhere but I am lost on this one.
 
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thorock

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Re: volvo 3.0 glp-c circulation pump hose swells and shoots off.

Don S said:
Have you read this thread yet? http://forums.iboats.com/volvo-pent...t-housing-circulation-pump-45-psi-604924.html same engine, same problem.
Click to expand...

I did find this thread after I posted. Seems like I bought his boat. I have a new temp switch and all else is similar. I did go out and pull the thermostat housing again. I kept drilling, increasing the size, until I felt I hit new metal. 1/2 believe. I also increased the size on the inlet side of thermostat. I ordered a new one anyway. The pressure dropped. I now have 25 psi at 4200 rpm. Hose does not pop off and vacuum went up to 12. Is 25psi going to be too much still? I did ness up the thermostat when I was drilling, but at least I am heading in right direction. Thanks for the help. any more ideas or wait till new housing comes in?
 
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jschul87

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Re: volvo 3.0 glp-c circulation pump hose swells and shoots off.

Did you ever come to a resolution on this? I have a 3.0 OMC cobra engine and it has been running hot at 170-180 at 3-4000 rpm. This past weekend the U shaped hose from the thermostat actually busted in middle of the hose. It must of dumped 30 gallons of water in the boat as we were heading back into the marina. Now I am not sure if it was swelling and popped under pressure or was just corroded and worn. When I pulled the hose off it looked like the thermostat housing was loaded with rust and lots of bubbling inside the metal. I pulled the thermostat and it looked like a 20 year old battery. I am going to put a new hose on and replace the thermostat but sounds like I may be having some of the same issues and want to make a decision on the boat before I start replacing everything on it.
 
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thorock

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Re: volvo 3.0 glp-c circulation pump hose swells and shoots off.

I am still waiting on the new thermostate hosing to come in. I did take the boat out all weekend and never had a problem with it after drilling the thermostate housing out. I still get 20 psi at full throttle but I am sure the new thermostate housing will fix that. My thermostate housing bypass hole looked normal and round and not too rusted so I thought. I drilled out the hole to .5 inch before I started hitting new metal.
 
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harmonicat

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Re: volvo 3.0 glp-c circulation pump hose swells and shoots off.

Did you ever find a solution to your problem? I'm going through the same thing but on a 4.3 and so far am at a loss as to why.
 
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thorock

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Re: volvo 3.0 glp-c circulation pump hose swells and shoots off.

I put a new riser on. No more pressure.
 
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dypcdiver

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Re: volvo 3.0 glp-c circulation pump hose swells and shoots off.

Yep, and all you needed to do was to file down the corrosion on the inner exhaust tube and make sure the rubber bellow/hose was installed in such a way as to not restrict the flow of cooling water.
Hopefully others will see this as it is quite common.
I have previously posted this solution elsewhere.
 
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aerobat

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Re: volvo 3.0 glp-c circulation pump hose swells and shoots off.

dypcdiver said:
Yep, and all you needed to do was to file down the corrosion on the inner exhaust tube and make sure the rubber bellow/hose was installed in such a way as to not restrict the flow of cooling water.
Hopefully others will see this as it is quite common.
I have previously posted this solution elsewhere.
Click to expand...

sorry to pick up the old thread but i today also blew a hose to the circulating pump on the 3.0 GS . that happened never before and now it happened just two hours after installing a new riser and somehow i do not believe in concidence.

you mean with the bellow/ hose the one which connects the riser with the steel exhaust pipe ? what can be done wrong there ?

i posted it in this thread :

http://forums.iboats.com/volvo-pent...e-between-t-stat-circulating-pump-644576.html
 
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The Law

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I had the same issue with my 3.0 GLP-D. I discovered that it was caused by the fresh water flush port not being completely sealed. I had installed a quick-connect with high-flow shutoff thinking it would make flushing out the engine easier. Instead, it seemed to allow enough air seepage in to cause a bubble, which caused abnormal pressure, and caused the hose to pop off. I went through 3 of these hoses and replaced the water pump before figuring it out. Not all bad, needed to do the water pump anyway. But if your large hose is popping off or bursting, check that your freshwater flush-out port is sealing securely.
 
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