replacing valve seals in a 79 ford 400 block

[mazdamama]

is there anything i shold know before attempting this task? this would be my first time, im somewhat mechanicaly experienced but i want to make sure i have everything i need and im not getting in over my head.
thanks, josh

 

[The Weasel]

Replacing them is pretty straight forward if you have a way to get the valve springs off and on. Are the heads being torn down for a valve job?

 

[mazdamama]

i was just going to take the valve cover and rocker arms of to replace the seals but im looking for suggestions from anyone more experienced.

 

[The Weasel]

I have never done it with the heads on the engine. There may be a way of doing this but I don't know what it is. The way I do it is to pull the heads off the block. I worked in a machine shop and we had these gun for taking off the valve springs. I would recommend taking the heads to your local machine shop and having someone there do it, or you could get one of these gun and do it yourself. Are the rocker arms adjustable?

Here is a link so you can get an idea of the tool to remove and reinstall the valve springs.
http://www.summitracing.com/parts/WMR-W89409/

 

[fordmike1]

I have done this a few times and its easy to do it with the heads on the engine still. Pull all the spark plugs out and put the engine at #1 TDC. Now get a socket/ratchet that fits the bolt in the front of the crank (sould be a 15/16") and turn the engine backwards about a 1/8 of a turn and then get a shoe string or a something simular and feed it into the spark plug hole untill you have just enough to pull the shoe string back out. Then turn the engine foward slowly untill it stops as the string will be up against the valves holding them up. Remove the rockers and springs for that cylinder and replace your valve seal. Once you are done with that cylinder just follow the firing order untill you havethem all done. Write down each cylinder once you do it just so you know its been done and that away you can make sure you get them all. Hope this helps you out as it alway worked for me.

 

[85_Ranger4x4]

I cut down a spark plug and welded a proper pipe thread nipple on it. Then I put a air nipple on in and hook it to air pressure which holds the valves shut.

Depending on the layout of the engine bay if it is still in the truck, I have had pretty good luck with my prybar type compressor. I just did my 302 on a engine stand last week and it worked perfectly for that. It also worked great for 5 of the 6 cylinders on my 2.8 as well. #2 required the screw down type because the heater box was right there... and the only reason that worked is I have a bodylift.