i want to seafoam the 460 engine in my '97 f-supter duty. it *seems* to work well for others. most write-ups i see on it say to pour it into the brake booster line so it distributes evenly to all cylinders. i dont have a vacuum booste line b/c of the hydroboost; right?

what other vacuum line would distribute to all cylinders?. it seems it woud be hard to pour it into the throttle body b/c it doesnt open to the top, but to the front.

any advice?

 

Does yours have vacuum operated cruise control, or electronic? On mine there is a fitting on the backside of the TB, right in the center, that goes to my cruise control, that's the one I would use.

 

You can use it on most all vacuum lines. But you dont pour it into the lines, you stick the line in the can and let it suck it up. Dont let the engine die.

 

This is not quite true - you need a vacuum line that goes into the throttle body, otherwise it will dump into only 1 cylinder, such as the PCV line on a Windsor motor, for example. If you are using a line that goes into the intake plenum, you would want one that is in the center of the plenum. The PCV line I spoke of is in the plenum, but it's way out on the end nearest the #8 cylinder runner. This is probably less of an issue on the 460 as it does not have the huge intake plenum the Windsors do.

 

Says right on the can you can hydrolock your engine by sticking the vacuum line on it. Pour it slowly into the vacuum line.

 

Pour vs. suck, no difference, you are equally likely to hydrolock if too much liquid goes in at once, but if engine is running high RPM and you're using a vacuum port that is equidistant from all of the cylinders it's not probable.

It's much easier and less messy to use a small hose and momentarily dip it into the can - let the engine vacuum do the work for you. You control how much goes in at once by how long you let the hose draw liquid. Not rocket science.

 

I like the, use a small funnel that fits into the vacuum line and control the amount you pour in methed. I'd not put the hose into the can that seems to be chancing it.

 

May not be rocket science but if you use the brake booster line and throw that into the can, you can suck the whole can in in a matter of seconds. Which is why it states to pour it in. Using a smaller line, then yeah it may be just fine.

 

ok, so it sounds like i should be looking for the pcv valve and pouring it into that.

thanks

 

not sure where the pcv is on a 460, but you want one from the center of the plenumUse a line off the vacuum tree in the middle of the intake. That way it evenly distributes to all cylinders

 

I just poured most of a can in the front tank, filled up, and ran it. I've used it down the throat of carbed engines before with great success. I ran that tank out on the highway, can't say I've noticed anything, but it ran great before. Just wanted to clean it up a bit.

 

i pulled the line to my boosters on all 3 trucks an didnt have any problems at all

 

I did the same as trapperjack and poured it in the gas tank. I read in some posts here that it would help pass inspection. I drove the truck using the tank in which I had placed the seafoam until I only had a quarter of a tank than had it inspected. It barely passed and I attribute this to the foam.

 

If I use the vacume port method, as opposed to the "in-the-tank" method and Seafoam works as expected, what effect is there on the cat & O2 sensor ??? Dave

 

Putting the seafoam in the gas tank will clean injectors and fuel system.
Sucking it through the booster hose slowly is what I usually do, but you can stall the motor easy if it goes only into one cylinder like mentioned before.
Find a vacuum line that's common to all cylinder to use. I've stuck the line into the bottom of a funnel as well. It works well when using a short and small line. I've never had a car or truck stall that way.
Sucking it into the engine with vacuum line will clean the carbon off the valves and pistons better.

On a side note.
All my speed density vehicles (as well as all the school busses I've worked on) typically get a healthy dose of the garden hose while revved at 3k. Mist it in... Don't choke it.
Works awesome to clean out the buildup.