Tips for removing valve stem seals

[tercle]

I have the rocker arm assembly removed.

What tool(s) should I use to remove the seals?

What's the best way to install them without damaging?

[xirdneh]

I have the rocker arm assembly removed.

What tool(s) should I use to remove the seals?

What's the best way to install them without damaging?

old ones get pretty hardened so i wedge them off using a large screwdriver
installing new I push them on with my fingers
they have a lip that snaps over the groove on the guide
after pushing them on i spin them a bit to make sure they are over the groove all the way

[Petros]

You can not remove them with just the rocker assembly removed, you need to rent or borrow a spring compressor to take the valve spring retainer and keepers out first. Autozone rents (for free) a tool for removing the valve spring retainer. I would also highly advise doing this one cylinder at a time, make sure the pistion is at top dead center BEFORE you remove the valve spring retainer. If the valve falls down into the chamber you will have to pull the head to get it back.

In fact I would do this: remove the spark plugs, put a length of soft cord into the cylinder (leave the end handing out so you can pull it out when done) and than turn the crank to raise the piston to the top untll it stops. This will hold the valves in the closed postion without harm. Than you can remove that cylinder's valve spring retainders, springs and than the seals as Xirdneh describs (there are tools for removing the seals, but just levering them off is all you need, even a large claw hammer could work). Do not expect to resue them, they get damaged when you remove them. done one cylinder at a time, put it all back together before moving to the next cylinder.

Carefully install the new seals, sometimes you can lube them and wiggle them on by hand. You can gently tap them downl with a soft or plastic hammer, but be very careful since you can damage the seal this way. If you can find a small socket that fits on it so it only touches the metal part you can use that to drive the new seal in place, but again do it carefully since you can still damage the seal.

It is not so difficult once you do the first one and see how it all works.

Good luck.

[xirdneh]

ha
petros, i missed that

[tercle]

Oops.
Tired. Forgot to mention I am working on a spare head that is removed from the engine.
I have the 27040 valve spring compressor tool rented from Autozone.
I was hoping to work on this head and have it ready for this dry weekend, and make a quick swap.

Did I mention I am replacing a head gasket (Petros Style)?

A few minutes ago, after removing #2 exhaust valve, I was looking at the valve seat and there's a crack between the exhaust and intake seats at the narrowest point. Those two seats are closer that the other pairs, and I am guessing someone ground them too far.

But I still have the seals and will use your ideas on the head that's on the engine.
I guess I can also practice removing seals.

When I pulled this head last year, I was impressed by how nice the spark plugs looked. I figured that was an indication it was a good head.
Is it common to get a crack like this?

http://i46.tinypic.com/2rwmjiu.jpg

[4doorVIP]

if anyone is ever replacing VSS with the head on, get a set of valve seal pliers and the toyo tool

toyotool - http://www.toyotool.com/



valve seal pliers - http://www.amazon.com/CTA-Tools-2205-Va ... valve+seal

[larry mcgrath]

Boy that is sweet

[tercle]

I found out today that there is a similar crack between the valves on #3 cylinder.

Is this a problem? Is the head bad? Is it nothing to worry about?
I did some web searches, and it appears these are common on Dodge 2.5L and VW heads and usually isn't a problem.
The spark plugs on 2 and 3 look just as good as 1 and 4.

[Petros]

I do no think it will be a problem, that is common on cars with large exhajust seats that leave little aluminum metal between the edges of the seats. It is possible someone replaced the valve seats with slightly large ones, it only cracked because it was thin, below the seat it will have the same amount of metal. These crack common in the ford ranger engines too.

be sure to install new exhaust valves while you are at it, along with the stem seals.

[tercle]

Thanks, Petros.
Here is the crack on #3.

http://i47.tinypic.com/34qsnx5.jpg

[tercle]

How important is valve spring Free Length to these 3A engines?

The book says they should be 44.6 mm.

These springs are between 42 and 43mm.

[xirdneh]

i just went thru this recently
the springs were short about .04"
the local machine shop guy said i could shim them with extra washers (under) up to .060"
i used 1 set of washers from another head that i had
they were abt .02" thick
he said it was more important to check springs for pressure at a FSM compressed height
but that would have cost about 15-20.00 for him to test them
so i opted out of that
the head worked fine before it came off the engine it was on
he said to look at the seat face angle of the valves with a magnifying glass
if the surface of the seat was flat the spring is probably ok
if the seat surface is not flat it is because the valve is rocking a bit due to a weak spring
thats all i know abt that

[tercle]

My springs are short about .08" or 2mm.
I wonder if two extra washer/spacers would be OK.
Does someone sell those washers? Because I don't see stock springs at Rockauto or anywhere.

[Petros]

I would think someone sells replacement valve springs. What I did was asseble 3 heads worth of springs from various junk 3a heads, or you can get one from a self service wrecking yard for abotu $30, and than pick the best 8 valve springs.

The seat pressure is the best way to determine which springs are best. You can determine this yourself if you have a drill press, or the use of one. with the drill press off you simply put a large bolt in the chuck, set the depth on the drill press so you get the proper compression length, and put a bath room scale on the work surface. The drill press pushes down on the spring to the correct depth and you can measure the pressue on the scale. simple, you do not need a costly valve spring testing machine (use used this method in the Nissan race shop btw, to test the valve springs that went in 1000 hp 3.0 liter v-6 that red-lined at 9,600 rpms). It would be useful to have fairly accurage digital scale, but for a street car any scale would be good enough. You mostly want them all the same, no weak ones in the group.

Baring any damaged springs (the compession test will determine that), what the valve spring pressue does if prevent valv float at high rpm. Since this is not a particularly high rpm motor, it will not really affect you much. So just make sure all are the same strength within about 10 percent.

the extra washers are the hard steel ones under the springs to prevent the spings from chewing into the aluminum head, you might just add an extra one. You can get them out of a used head from the wrecking yard, or off the head you pull on your car. the only concern with shimming the springs is that you have enough clearnace that you do not bind the coils at the top of the valve lift. Since the stock cam profile is not a very high lift camshaft, not much chance of that happening. If you tryh the extr shim, it would be best to verify that you can get a feeler gauge between the coils when it is at max lift after you put the cam shaft back on.

[tercle]

Excellent.
Well, I have pried off the valve seals and understand that operation now.
The camshaft looks better than my FWD 5spd wagon that is awaiting a transmission, so I will keep that.
The head on my new car has only 161k on it, so I am betting that one has better springs and is a better head overall.

So I will pull the head next Saturday and decide which head is better, and save the sandpaper and stem seals for the winner.
And I have a set of washers from this practice head.

xirdneh: I looked at the valve faces, and they are concave.