Hello All

Anyone replaced the Valve Stem Seals and Cushions, without removing the Head?
If so, how?

Bolt Torques, etc.

It was suggested to pressurize the Cylinder, but that should force it to Bottom Dead Center.

It was suggested using the rope trick so the valves will not fall into the Cylinder, but how does one remove them to get to the Seals?

Any advice, would be appreciated.

You will need an "on the car spring compressor". It really is not that tough if you have the tools. Remove the timing belt, valve cover, and cam shaft. Pressurize the cylinder you are working on, remove the valve shim bucket, compress the spring, remove the keepers and the spring, replace the seal, reinstall the spring and keepers, put in your new cushion, reassemble, do it 7 more times and you are done.

The trick is to put enough pressure in the cylinder to keep the valves seated and not enough to push the piston. It is going to have to rotate all 4 pistons and the other 3 holes will have spark plugs in them still so it won't be real easy to turn over. You will want the cylinder you are working on to be on TDC so in the event that a valve unseats it does not drop down into the cylinder. Wouldn't that be a nightmare? Are you familiar with a cylinder leakdown test? It is a tool that you use to pressurize a cylinder at TDC and it has two guages on it. One that shows the amount of pressure going in and one that shows actual pressure in the cylinder. While using this tool you typically run anywhere between 50-100 psi in the cylinder without it pushing it one way or the other. I have had pistons that have actually moved enough to pop open a valve (the cam is in place so it opens the valves) but this is very rare. If you just put in 50 psi or so it should work fine. If you have any doubt just pressurize it before you turn the valve loose.

Torque specs:
Cam bearing caps 15 ft. lbs.
Cam gears 36 ft. lbs.


Mark

Thanks for that bit of advice Mark. Volvo quoted me $800 to do it and said that I may have worn Valve Stems/Guides, due to the Previous Owner using the wrong gasoline. He suggested that I should just remove the head and have it reconditioned . . . cheaper in the long run, according to him.

My situation is: My B21A only started smoking on re-acceleration, after coasting downhill -After Volvo Dealership adjusted Valve Clearances. It never smoked before that. I am suspicious. I am not in the mood to give them $800.

I suspect adjusting the Valves created more Vacuum, drawing oil in past the Seals.

Any ideas or advice or experience would be appreciated.

Well, your description of the smoking problem does sound like a pretty text book case of bad valve seals. Being caused by using the wrong gas? That one eludes me there. I can see running unleaded fuel in a car without hardened seats causing a problem, but even then it is going to take tens of thousands of miles to do so. They way I see it you do not have a great deal of options on this one; fix it yourself, pay someone to fix it, or live with it. Where do you want to spend your money? On the in the car spring compressor and not pull the head or spend the money, and more of it, on the necessary gaskets required to pull the head and send the head out for a valve job. I have no doubt you could rent a conventional valve spring tool, but you need to have the head off of it to do it. I wonder if you could rent the on the car model?

Mark

I've used the rope trick recently. String actually, not rope. Feed in a few yards, and wind the piston up to TDC. Lock the crankshaft securely by tieing the handle of the wrench to the steering pump.
You don't need a special tool to compress the springs - just a tire lever with a large hole in the end, and a 2" bit of pipe with a cutaway so that you can extract the valve stem collets. Hook the lever onto the nearest camshaft bearing bracket bolt using a large washer.
The stem seals just push on neatly over the end of the bush.

Are there pictures of the tools you used?
--
1980 245 Canadian B21A with SU carb and M46 trans

Sorry, no. But see the later thread, where I describe it in more detail. Once you think about what you are trying to achieve, the basic design is pretty obvious. You just need to lever down on the top of the spring assembly, but in a way that still gives access to the recessed collets.
There may well be proper tools that do the job. Maybe you could modify it so that it stays compressed by hooking on to something. Two hands would certainly make the collet extraction job easier!