AQ125A experts

[raven1978]

I need to replace my circ pump and noticed there is an updated pump, part number 3587508. Has anyone used this replacement part number, and if so, is this the equivilent to an automotive pump now?

 

[Fun Times]

Re: AQ125A experts

Doing some research if the auto circulating pump will work/fit on the AQ125A engine, the consensus is no they are not going to be interchangeable. Looks like they made a change with the AQ131 though.

http://forums.iboats.com/volvo-pent...g-pump-1983-aq125a-same-volvo-b21f-55196.html
http://forums.iboats.com/mercruiser...rives/how-rebuild-circulating-pump-55231.html

I would say that the B230 is an improvement over the B21. If you are considering upgrading, I would go for an AQ131: it has the same power and engine block as the AQ125B, but it has the advantage that an automotive coolant circulating pump can be used as a replacement if the original fails."

 

[jerryjerry05]

Re: AQ125A experts

Since it's a Volvo replacement part.
I doubt you'd have any trouble.
Not very often the circ pump goes bad.
Is it wobbling or screeching?
Just making sure your not wasting $$$
Most times an overheat is due to the manifold or heat exchangers.

 

[raven1978]

Re: AQ125A experts

Its tending to overheat when a load is put on, at idle 180-185ish, underway 210. This year alone i have had the H/E cleaned and tested, replaced impeller, replaced waterneck and gasket at the drive,replaced thermostat, I have also replaced ect sensor since i had wackey readings on the dvom. I have also tried a different temp gauge and shot I/R gun at the block. Both gauges say 210 undr load while ir gun say 160. Fresh coolant this spring, and have also used jumper wires to eliminate the boats wiring. This is a freah water boat and the manifold is cooling properly. Hence why i think its the circ pump. If you can think of something i missed please do speak up cuz im scratching my head if it isnt the circ pump.

 

[Scott Danforth]

Re: AQ125A experts

if your IR gun says 160 go with that and find what is wrong with your gauges, wiring and sensor.

The IR gun is a precise diagnostic tool, where the temp gauge in the dash is merely an approximation of temp based on the cheapest gauge and sensor parts that could be made and packaged into a temp gauge.

 

[raven1978]

Re: AQ125A experts

if your IR gun says 160 go with that and find what is wrong with your gauges, wiring and sensor.

The IR gun is a precise diagnostic tool, where the temp gauge in the dash is merely an approximation of temp based on the cheapest gauge and sensor parts that could be made and packaged into a temp gauge.

But if i have used all new gauge, sensor and wiring and still have the same reading as before with old gauge,wiring and sensor...?
Ir gun is a good tool but not 100%, i dropped a temp prob into the expansion tank and het a reading of 185-190 at idle.

 

[Alan Lloys]

Re: AQ125A experts

The new version of the pump is really a modified automotive pump.
I have the 125B which is even more difficult to find a pump for.
I bought a Volvo automotive pump, cut the extended spout of and then JB welded in an adapter.
The simple aluminum adapter was machined by a friend and the pump was about $ 45
You need to change the connection to a flex hose instead of the plastic spacer.



I have been running that way for the last 2 years without any problems.
I am attaching a picture of my setup. As best I can find the "A" version should be a straight shot whereas the "B" version has a bit of an off-set. As you can see in my setup the flex hose is making up for the offset.

 

[jerryjerry05]

Re: AQ125A experts

Even a fresh water boat the exhaust manifold or heat exchanger can go bad.
The Volvo circ pump is $400 US not sure what that'd be in Canada?
The Volvo manifold is $1400 WOW!!!
I've seen them as low as $290
Lots of aftermarket places that are way cheaper.
This site sells them.
Your motors 30years old.
Just from setting it can go bad at that age.
If it slowly overheats the manifold is the likely culprit.
If you've ran in the Great Lakes? The Zebra mussles can have an effect on the exchanger.
Just flushing the exchanger is not a guaranteed fix if it's clogged.
The best way to check them is do a flow test.
Gonna take some rigging to set up something to test it with.
The local radiator shop might be able to help?
I worked on a Bayliner with the same setup as yours(actually a bunch of them).
The guy had the same symptoms.
I started checking.The exhaust manifold looked brand new.
I reached down and felt the freeze plugs and I poked a hole in the top with my finger.
The manifold, during the normal operation the manifold kinda drains itself.
The internal is left exposed to the air and the air is worse than leaving it under water.
The air accellerates the rusting.
Take the manifold loose and check the holes that the water comes out.
The fresh water manifolds can last 15-20 years if you got 30 you done good!!!