Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

Should i use rtv???

Thread Tools
 
Search this Thread
 
Old Aug 3, 2009 | 10:41 PM
  #1  
ar156920's Avatar
ar156920
Thread Starter
|
New User
Joined: Aug 2009
Posts: 4
Likes: 0
Should i use rtv???

Got a '79 f-250 351m was leaking out of the valve cover gasket replaced old rubber with new cork gasket now it appears to be leaking from a new spot. It tends to only leak at high rpm also. can this be solved by pulling the gasket and putting some rtv down first???
 
Reply
Old Aug 3, 2009 | 11:35 PM
  #2  
fmc400's Avatar
fmc400
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Club FTE Gold Member
Welcome to FTE. You for sure want to tack it down to the valve cover with a light bead of RTV. Whether or not you put a bead on the cylinder head flange is up for debate, I'd try it without first. The important thing is that you torque it down gently and evenly to specification, without overtightening. If the valve cover flanges are not flat, they won't seal. Big thing to remember with a cork gasket is that you have to re-torque it a couple times after it sits for a little while each time, because the gasket will relax. If you didn't do this the first time, that may be why it's leaking.
 
Reply
Old Aug 3, 2009 | 11:58 PM
  #3  
ar156920's Avatar
ar156920
Thread Starter
|
New User
Joined: Aug 2009
Posts: 4
Likes: 0
good deal, i'll check tightness. thanks
 
Reply
Old Aug 4, 2009 | 02:13 AM
  #4  
USArmyTaterness's Avatar
USArmyTaterness
Posting Guru
Joined: Jul 2009
Posts: 1,536
Likes: 0
From: Schweinfurt Germany
also if you continue to have problems with your cork gaskets leaking and for some strange reason the RTV doesn't stop any leaks another option would be to yet again get a new set of gaskets and some gasket sealer I have found even though a valve cover gasket should be oil resistant some manufacturers are cheapskates and they aren't so the sealer helps a bit
 
Reply
Old Aug 4, 2009 | 02:32 AM
  #5  
johnboy427's Avatar
johnboy427
Posting Guru
Joined: Jan 2005
Posts: 1,299
Likes: 2
From: The Vieux Ford, Kansas
I always use a thin coat to glue the gasket to the valve cover, just put it on your finger and spread it on 1/16 thick or so over the whole gasket. Never had one leak even with cheapo taiwanese chrome covers on a chevy. Makes installation a lot easier too.
-Johnboy
 
Reply
Old Aug 4, 2009 | 03:45 AM
  #6  
daddy172005's Avatar
daddy172005
Senior User
Joined: Jun 2008
Posts: 378
Likes: 0
From: Greenwood, SC
Ive always put it on the head instead of the valve cover. Never had a leak.
 
Reply
Old Aug 4, 2009 | 01:11 PM
  #7  
75F350's Avatar
75F350
Post Fiend
Joined: Jul 2006
Posts: 6,948
Likes: 44
I would lay odds on the valve cover flange being bent or otherwise distorted. If they were previously overtorqued they may naver seal until they are repaired.
I hate scraping the old stuff off and never use any type of sealant. Straight covers, even stamped steel ones will seal fine if they are straight.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
granny_rocket
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
6
Oct 23, 2013 10:47 PM
obscurity
1948 - 1956 F1, F100 & Larger F-Series Trucks
8
Jun 12, 2013 09:34 PM
78_f150
1973 - 1979 F-100 & Larger F-Series Trucks
19
Oct 17, 2011 11:03 PM
CCotten
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
9
Oct 12, 2005 09:29 PM
bulabula
Clutch, Transmission, Differential, Axle & Transfer Case
8
Mar 17, 2002 10:02 PM




All times are GMT -5. The time now is 06:07 PM.

story-0
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-05-30 18:33:59


VIEW MORE
story-1
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-2
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-3
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-4
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-5
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-6
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-7
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-8
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-9
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE