Valve Stem Seals - Replace Without Removing Head
Started by
haggisfrog
, Mar 21 2013 02:49 PM
16 replies to this topic
#16
MRA
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Previously known as 'mra-minis.co.uk'.
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Posted 21 March 2013 - 10:04 PM
It is possible, but you wont drill out a spark plug, the ceramic needs to be crushed and removed carefully, it can be very sharp, 100psi on a valve is not always sufficient so be careful, always have the piston at TDC for each individual valve spring pair. the tool is a simple lever, gently (after undoing the rocker adjuster) move them aside to access the spring, cap & collets. However as Cooperman says if its that bad its only a bodge to save a bit of oil
#17
dklawson
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Moved Into The Garage
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Posted 21 March 2013 - 10:31 PM
I have done what you are asking about. Before I tell you the method I would like to state for the record that while you can replace the stem seals with the head in place, it probably is only a temporary fix. In all likelihood the valve guides are worn and your new seals will only help for a short while.
That said, use the rope method to hold the valves up. It is quick, easy, clean, and very effective. While compressed air may work, sometimes the collets are stuck so tightly to the valve stem and keeper/seat that the valve stem is driven downward (unseating the valve) anyway. The rope is a very firm stop and never fails.
For an overview of the method, see my friend Todd Miller's web site for the Austin America.
Todd's Web Site
On the left side of the home page, click the "Technical Advice" link.
On the Tech Advice page, scroll down in the "Categories" section and select "Engine".
Near the bottom of the Engine page is a section discussing "Cylinder Heads and Oil Consumption".
Valve seal replacement is discussed there and he has a picture of the tool I made and used for the task.
The tool I made is modeled after a commercial item available form K-D Tools. Someone in the U.K. is bound to offer a similar item.
K-D Brand Compressor
Better Picture of K-D 8037 Tool
The link below is to plans for the on-head spring compressor I made.
Word Document Plans for Doug's Compressor
If you choose to make your own spring compressor from the plans above, use a brass pipe nipple for the pressure foot so it won't be magnetic.
That said, use the rope method to hold the valves up. It is quick, easy, clean, and very effective. While compressed air may work, sometimes the collets are stuck so tightly to the valve stem and keeper/seat that the valve stem is driven downward (unseating the valve) anyway. The rope is a very firm stop and never fails.
For an overview of the method, see my friend Todd Miller's web site for the Austin America.
Todd's Web Site
On the left side of the home page, click the "Technical Advice" link.
On the Tech Advice page, scroll down in the "Categories" section and select "Engine".
Near the bottom of the Engine page is a section discussing "Cylinder Heads and Oil Consumption".
Valve seal replacement is discussed there and he has a picture of the tool I made and used for the task.
The tool I made is modeled after a commercial item available form K-D Tools. Someone in the U.K. is bound to offer a similar item.
K-D Brand Compressor
Better Picture of K-D 8037 Tool
The link below is to plans for the on-head spring compressor I made.
Word Document Plans for Doug's Compressor
If you choose to make your own spring compressor from the plans above, use a brass pipe nipple for the pressure foot so it won't be magnetic.
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