leakdown test failed

[Anonymous-0]

Leakdown test failed on 9n I will try to reseat valves, any Idea on what's the best way to get valves clean. alot of carbon deposit on steam and around seats but seat surface looked ok, not new but? Thanks for the help. Peace Shane

 

[JohnMD]

Pull valve assembly out, take apart, and clean up with a brass wire wheel. Scrape top of block and finish with brass wheel. Wash down with parts cleaner when finished. Hand lap valves if valve and seat in good shape. Keep parts together so all valves, spings etc. go back in the same placed they were removed.

 

[Dell (WA)]

Shane.........I assume you also did the dreaded "wet" compression test to verify ring sealing???

What JohnMD sez: brass wirewheel is "soft" and doesn't abrade steel valve stems, just the softer "carbon". Usually ONLY EXHAUST stems gitt "carbonized". Usually ONLY EXHAUST valve heads gitt burned. Professional grinding is required. Usually ONLY EXHAUST valve HARDENED seats gitt pitted. Professional grinding is required. Sometimes you can gitt the valve grinding shop to do an "inplace" service call like the big guys do for $$$, but generally you'll haffta haul block to the valve shop.

Usually INTAKE valves only need slight swirl with valve grinding compound..........Dell