120 Lehman overheating

[sunchaser]

If you change out your impellers every 12* - 18 months you won't be digging out pieces and overheating. Has anyone seen an impeller crater in a year - excepting run dry periods?

 

[Andy G]

A quick question on impellers. Broken impellers are always a potential problem, they are pretty flimsy things. Are there more robust options out there?*

Impellers have*always seemed to to be the achilles heel of the Lehman.(apart from its water pump)

Regarding the post, I would still be a little concerned as to where 2 gallons of fresh coolant got to, and why, the broken impeller pump doen't account for it.

 

[Marin]

shrimp wrote:
Impellers have*always seemed to to be the achilles heel of the Lehman.(apart from its water pump)

*As the owner two Lehman 120s for the past 13 years I have not found that to be the case at all.* We do not change our impellers every year or even every other year.* We change them every 200 - 300 hours, whenever I feel like dealing with it during that envelope.* Granted, we use the boat year round so the impellers are not sitting in one position for weeks on end.* And about five years ago we switched from the stock raw water system to the 1" Johnson pumps.* But in both cases--- Jabsco and Johnson--- the impellers that came/come out look exactly like the impellers going in.* In fact every time I do it I ask myself why I didn't leave them in for another 100 hours or so.


-- Edited by Marin on Thursday 4th of August 2011 11:47:52 PM

 

[FF]

Broken impellers are always a potential problem, they are pretty flimsy things. Are there more robust options out there?

My way is a Y style strainer after the pump that simply catches the impeller pieces. Inspection is fast and easy .

When the imperller fails , no attempts at back flushing (to hope to get all the chunks) is required.

 

[Andy G]

Having lost an engine to an impeller failure, I am a little nervous of repeating the experience.

 

[tomtomterrific]

Guys,

A quick follow up question. Anyone know where I can get paper gaskets for the jabsco pump seperately?

I had to a gaskets from the second kit I had as well as some sealer on the R&R of the impeller.

So now I'm shrot a gasket for the second kit. I'd also like to get some spares in case I run into the same issue again.

Thanks!

Tom

 

[Larry M]

tomtomterrific wrote:
Guys,

.....Anyone know where I can get paper gaskets for the jabsco pump seperately?...

*Tom:* The Jabsco part # is:* 3298-0000*

Just google it.

 

[tomtomterrific]

Thanks Larry!

 

[mitch m]

i had a weird engine overheat problem that was eventually traced to loss of coolant occurring from minute cracks in the water heater hoses abrading on the bulkhead between the engine room and water heater. the tiny cracks caused loss of coolant and it was a devil of a time finding where the coolant was coming from as it was running down the inside of the bulkhead on the water heater side and ending up in the bilge. i kept noticing that i had to top up the coolant overflow container after each long run, and that the temp was running hotter than usual. but there was no coolant drip or loss under the engine area. i even taped a terrycloth towel 'diaper' under the engine to see if i could find any drips out of say the antifreeze on-engine pump. finally with engine cold, i got a stant tester , put it on the radiator cap, and pressurized the the coolant system to about 7 psi. i saw a huge jet of coolant blowing past the heater hoses where they entered the bulkhead.. problem solved for about $50 of new hoses (now installed with abrasion protectors ...). i also put in a borel exhaust temp alarm as a double check on the engine's own overheat alarm..

 

[magicdelmar]

I am in need of a face plate gasket for my jabsco water pump on my ford lehman 120. Can anyone point me in the right direction. I am also replacing the pencil anodes on the coolers,,are they 1/2 inch in size. Thanks.

 

[sunchaser]

With Jabsco, gaskets are included with new impellers. Or make one or use Loctite 518. For zincs, any good boat store will have them or page 39 Defender's 2013 catalog.