Author Topic: Valve guide seals  (Read 1794 times)

rrloyd

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Valve guide seals
« on: September 02, 2019, 11:11:49 »
I know it is time to replace my valve guide seals.  My question(s) are.  Cost, any idea what I can expect to pay?  Can the seals be replaced with the head in place or does it have to be removed.

ja17

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Re: Valve guide seals
« Reply #1 on: September 02, 2019, 13:54:28 »
 If the engine has low miles and a good service history, then you might have good results replacing just the old, age-hardened valve seals. You do not need to remove the head for just valve seal replacement. Otherwise it is probably time for a total head reconditioning, "valve job" because the valve guides and valve stems wear also.  To recondition the cylinder head, it is removed, so the valve seals and valve guides can be replaced. At this time the valves and seats themselves are re-conditioned or replaced also. A mew head gasket is installed.  The head can be "milled" or welded if needed. Just replacing the valve seals alone, does not require head removal. Factors to consider are the history of the engine, (miles, service records, oil usage, coolant usage, and visible exhaust smoke).Replacing the water pump, belts and hoses during this procedure is good preventative maintenance.
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

rrloyd

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Re: Valve guide seals
« Reply #2 on: September 02, 2019, 15:08:51 »
Thanks for the reply Joe.  I did the head completely about 10,000 miles ago.  But those 10k miles have taken nearly 30 years.  I think the head is still in good shape and will do a compression test later this week.  My tester died, I've ordered another and will do the check when it arrives.  Do you have any idea the approx. cost for only replacing the seals?

ja17

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Re: Valve guide seals
« Reply #3 on: September 02, 2019, 19:33:48 »
Yes, with only ten K your head and guides should be fine. Back in the day an experienced mechanic, factory trained with all the special tools, on a new engine, and in ideal working conditions, could do the job (valve seal replacement), in three to four hours. Good luck these days even trying to find someone to do the job. The price will vary widely and you will have to search for someone who can do it.

After a long storage, sometimes just using the car again will bring old dried out seals back-to-life, if your lucky.
« Last Edit: September 03, 2019, 01:32:35 by ja17 »
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

MikeSimon

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Re: Valve guide seals
« Reply #4 on: September 03, 2019, 00:42:32 »
O.K., Joe! Any reputable outfit in Ohio that can redo my head?
1970/71 280SL Automatic
Sandy Beige
Parchment Leather
Power Steering
Automatic
Hardtop
Heated Tinted Rear Window
German specs
3rd owner

ja17

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Re: Valve guide seals
« Reply #5 on: September 03, 2019, 01:36:38 »
Hi Mike,
My local cylinder head machinist just passed away this spring. These old skilled workers are disappearing. In your area, I would check with Ted Godfried for a good reference.
« Last Edit: September 03, 2019, 01:43:22 by ja17 »
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