MD2B Oil Pump / No Oil Pressure

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Balestrand
Posts: 17
Joined: Jun 7th, '11, 11:09
Location: Spondee -- CD 28 #57, Camden ME

MD2B Oil Pump / No Oil Pressure

Post by Balestrand »

Hi, Everyone--

I got the MD2B started up on my CD28 this spring, and the oil pressure warning light is staying on. (I changed the oil last thing in the fall.) I've checked the dipstick and strainer seals and replaced the sensor-- but light still on. There is a pretty good discussion of the matching problem and a solution (remove flywheel to access oil pump, prime oil pump) here:
http://www.ybw.com/forums/showthread.ph ... ssure-md2b

But before I dive into that, I'm wondering if anyone
1. has a different idea;
2 tips or warnings about accessing the oil pump;
3. good suppliers for a replacement oil pump, if necessary.

Thanks,
Robert
CD28 "Spondee" Camden Maine (currently in Brunswick)
User avatar
Frenchy
Posts: 614
Joined: Mar 14th, '15, 15:08
Location: CD 33 "Grace"

Re: MD2B Oil Pump / No Oil Pressure

Post by Frenchy »

I think your best bet is to have a professional measure your oil pressure with a mechanical gauge. Either that, or if you can,
do it yourself. The gauge on your boat could be bad, or the wiring not grounded, etc. If the mechanical gauge still
shows a low reading after the engine is warmed up and at idle, it's time to investigate further. It could be a clogged pickup
screen on the oil pump or a broken pressure relief valve as well as a bad pump. Since the pump operates in a oil bath,
it usually is pretty reliable. Good luck in tracking this down. - Jean
Jean - 1983 CD 33 "Grace" moored in
Padanaram Harbor
Massachusetts
Balestrand
Posts: 17
Joined: Jun 7th, '11, 11:09
Location: Spondee -- CD 28 #57, Camden ME

Re: MD2B Oil Pump / No Oil Pressure

Post by Balestrand »

Thanks, Jean.
(I'm wondering if anyone out there has ever primed their oil pump through a small hole in its side?)

It's just a sensor with a warning light-- no gauge-- and I put a new sensor in. So I feel confident the pressure is low (though I will see if I can find an actual gauge that might fit there). I saw someone on the YBW board mention a hole to prime the oil pump, which I think might be the "plug" (#13) on this schematic of the pump:
https://www.marinepartseurope.com/en/vo ... 13747.aspx
I think I can access that without removing the fly wheel (which I have never done). So I will find a pistol-style oil can and see if I can get a prime going there. After that, sounds like I should get inside that oil pump.
Thanks,
Robert
Balestrand
Posts: 17
Joined: Jun 7th, '11, 11:09
Location: Spondee -- CD 28 #57, Camden ME

Re: MD2B Oil Pump / No Oil Pressure

Post by Balestrand »

Thanks, Everyone, for your help. Issue resolved: I removed the fuel pump (without removing the fly wheel) and primed it. I was sure I'd spilled too much out to be effective, but the pressure returned! Light came back in after a day's passage and then a night passing-- on morning start up. I had managed to open the small hole between the pump and the dipstick. The schematics I've seen indicate that hole as the spot for a pressure gauge nipple, it is so close to the oil pump intake (I now know), if gave it a shot: used a pistol oil can to over fill it, then turned the fly wheel about five times to spin the oil pump. Probably did this about 5 times. Re-started engine but decided to let it run longer with light on-- after about a minute, pressure light went off. So, I can't be sure if I did "prime" it with that hole, or if I just needed to wait until the light went off! One thing: next time I change the oil, I will use the refill holes atop each head, rather than the oil top off entry. Thanks again! Boat has made it to Camden...
~Robert
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