Author Topic: leak in cylinder wall?  (Read 2235 times)

john92110

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leak in cylinder wall?
« on: March 28, 2019, 00:28:49 »
Tearing down an old seized m129 engine, I got it freed up, but noticed on one of the walls corrosion? or pitting. Could this be porosity of the casting where water is entering?  Low miles but many years on a second bore 83mm. 
You can see a pit  just below the piston ridge.
Has anyone seen this before? Ideas?
How do I test?
Can it be brazed? or epoxied from inside the cooling jacket? looks like access is possible on number 4

Benz Dr.

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Re: leak in cylinder wall?
« Reply #1 on: March 28, 2019, 02:48:04 »
About the only way to fix that is to sleeve the cylinder. That engine is a mess.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

stickandrudderman

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Re: leak in cylinder wall?
« Reply #2 on: March 28, 2019, 11:05:35 »
As Dan says, you'll have to have it sleeved. 

john92110

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Re: leak in cylinder wall?
« Reply #3 on: March 28, 2019, 14:21:57 »
 I read up on it it sounds like a plan. Question... can I use the original rings since there's hardly any wear?

ja17

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Re: leak in cylinder wall?
« Reply #4 on: March 28, 2019, 14:33:33 »
Old coolant becomes acidic with age. A M129 block should be not be a problem to sleeve.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Benz Dr.

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Re: leak in cylinder wall?
« Reply #5 on: March 28, 2019, 19:02:18 »
I would get new rings. The ones in that damaged cylinder will likely be chewed up from running against that rough area. Look at your piston/s as well and see if they're damaged too.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

stickandrudderman

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Re: leak in cylinder wall?
« Reply #6 on: March 30, 2019, 08:49:12 »
Never re-use old rings; you will regret it.

Shvegel

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Re: leak in cylinder wall?
« Reply #7 on: April 19, 2019, 22:05:52 »
I second not using old rings.  Way too far to go back if they don't seat.