Replacing Valve Stem Seals

I need to replace the valve stem seals on my wife's 1986 Jetta GLI. While it sounds like a fairly straightforward job, the cost of the tools has been the worst part of doing it myself.

I plan on using the "rope in the cylinder" approach to keep the valves from falling into the cylinder. I have an air compressor and the necessary spark plug adapter, but the rope method would let me work slowly (overnight if needed) and not worry about losing pressure if I bump the valve or something.

I found plans for building my own valve spring compressor, and plan to build one for this job. It looks like it should work nicely.

I'm still curious about the special pliers used to remove the valve stem seals. I can't really afford the $50-80 for a pair of "special" pliers. I found one post online from someone who used regular needle nose pliers, but I'm wondering if anyone else has used standard tools to remove the seals? Is it that difficult to do?

As for removing and installing the "keepers", is this very difficult to do?

I've read numerous reports that the seals can be "installed" using a deep socket that fits the seal properly. That's most likely the approach I'll use.

I figure I'll probably replace the valve cover gasket and camshaft seal while I've got things apart.

I've done lots of engine work over the years, including pulling engines, replacing cylinder heads, etc. But, I've never actually replaced the valve stem seals. As always, I get a bit nervous venturing into unknown projects. :)

Any tips or advice would be appreciated.

Thanks,

Anthony

Reply to
HerHusband
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Don't worry about it. You are going to toss the seals anyway. Just grab them with pliers and pull them off.

The keepers and retainer and valve stem accumulate varnish over time which glues all together. A quick tap with a spark plug socket and a small hamer separates them momentarily and breaks the bond. It may even pop the keepers out, which is how machine shops used to do it. Then apply your spring compressor lever and remove the the keepers with a magnet.

That's correct. The seals are probably metal jacketed with a small "step" just below the top. Your socket should fit over this. Some seals come with a plastic sleeve to protect the seal from the sharp edges of the keeper groove as it passes. Try to get and use one of those if you can.

Simple deal, just take your time.

Rex B

Reply to
Rex B

Rex,

I guess I'm just worried how much room there is to get ahold of the things. I've never taken the heads apart before, so I don't know how far down those seals sit, or what's around them.

Thanks for the info and reassurance! :)

Anthony

Reply to
HerHusband

Honestly, I have not done a VW. Worst case is they may sit into a well about 1" in diameter, and maybe 1.5" deep. And that's no big deal.

Does anyone have a link showing a bare 8V head?

Reply to
Rex B

When the spring is gone there's enough room. I also used a small plier to get them out. Don't think they come out the first try. You have to pull hard before they let go. When installing the new ones be carefull not to damage them. Use the included plastic sleeve.

SFC

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Reply to
SFC

Rex,

I finally got around to changing the valve stem seals in my wife's 1986 Jetta GLI. As with most first time projects, I was a little nervous going into it, but it actually went fairly easy.

The only "special" tool I had was a self made valve spring compressor I built following a design I found online. It worked fine.

I had planned on using the "rope in the cylinder" approach to keep the valves from falling into the cylinder, but every attempt at compressing the valve springs just compressed the rope instead. I tried about 2' of rope, then about 4', and then almost 6'. Same results every time.

So, I thought I would switch to the traditional air compressor method, using an adapter that was part of my compression gauge. But that didn't work either. After more head scratching, I realized the compression gauge adapter had a one-way valve in it. So, it was back to the rope method.

Then I remembered your comment about things being glued together. A couple of quick taps with the spark plug socket and a small hammer was all it took to break the bond. The springs then compressed easily.

One of those bonehead moments... :)

6 of the 8 seals came out easily with a standard pair of needle nose pliers. Naturally, the last two were stuck in there good! For those I used a pair of needle nose vise grips. A bit more grip and they came right out.

Naturally, my seals didn't come with the sleeve. But, I had a couple of sleeves left over from head gasket sets I had purchased over the years.

I used a deep 6 point 12mm socket on a 6" extension. It worked great. I put the sleeve over the valve stem, started the seal on the stem by hand, then seated it firmly with the socket.

I greased up the new seals slightly before sliding them on. I don't know if that's the proper way of doing things, but it's how I normally install other seals, and they slid down easily. I haven't noticed any problems.

The magnet worked great for removing the keepers. But, reinstalling the keepers was easily the most awkward aspect of the whole job. I needed the magnet to get the keeper near it's destination, but then had no way to free the keeper from the magnet. :) I spent a lot of time with the magnet and a tiny screwdriver putting the keepers back in place (while holding down the compressor arm), but eventually I got the job done.

I'm sure there must be a more elegant way of installing those keepers. :)

My heart sank when I tried to start the engine back up. The timing sounded really off and it wouldn't start. I made multiple attempts at resetting the valve and ignition timing, checking the plugs, etc. but had the same results every time.

After continued cranking, it finally started but the valve lifters made all kinds of noise, and the engine stumbled and jumped like an old steam engine. I feared I had seriously screwed something up.

But, gradually each cylinder quieted down, and the idle smoothed out. I stored the hydraulic lifters upside down while I had them out, just as my Bentley manual recommended. But, I'm guessing the oil drained out of them somehow anyway and it took a bit for them to repressurize?

Anyway, my wife's car is back up and running smoothly again, with no signs of smoking. Now it's just a matter of waiting and seeing if the oil consumption has decreased.

If all goes well, I'll be changing the oil, and replacing the oil pan gasket next weekend... :)

Thanks to everyone who offered advice!

Anthony

Reply to
HerHusband

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