Question About the Procedure for Replacing the 2F Valve Seals

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1979 FJ40ish

10 Year
Joined
Oct 24, 2015
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112
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328
Location
Clarksville, TN 37043
I have never done anything like this before, but that has never prevented me from diving right in and screwing something up, usually 2 or 3 times before getting it right.

I am getting ready to change the valve seals and springs on my 1979 2F engine. The engine is installed in the FJ, but the manifolds are off.

Everything I've been able to read and watch on YouTube seems to indicate that I should bring piston 1 to TDC on the compression stroke, change the seals, then turn the engine over to bring piston 2 to TDC on the compression stroke, change the seals, then repeat for pistons 3 – 6.

From what I have learned, both pistons 1 and 6 are TDC at the same time. One on the compression stroke and the other on the exhaust stroke. The same for pistons, 5 and 2, and 3 and 4.

I plan to use rope stuffed in the spark plug hole to keep the valves from dropping into the engine.

I have one of the rear wheels jacked up, and I’m turning it to turn the engine over. Since I’m doing this work by myself, it's hard to be at both ends of the cruiser at the same time.

Can I safely replace each set of seals, 1 & 6, 5 & 2, and 3 &4 at the same time, and only turn the engine 3 times to find TDC and not 6?

Thanks
 
Take all the plugs out, put it in a gear and just bump it backwards while watching the window.
 
With all the plugs out, sometimes you can turn the engine by pulling or pushing on a fanbelt...
 
IMHO you are only doing 6 jugs. Follow the firing order. Remove all the plugs. With piston at the bottom feed in rope - rotate crank to bring piston up - loosen rockers, slide over out of way, tie - change the parts - back piston down some, remove the rope. Move to next in firing order.

You may need to remove the whole rocker assembly (I'm not sure). I have a metal fan blade - I just grab it and pull to rotate the engine. On flat ground you can just put it in 4th gear and push the rig by hand to rotate the engine.

Big socket/wrench on crank pully nut.
 
Just use shop air with a compression test adapter and fill the cylinder with air. Way faster and easier and works great.

How are you planning on compressing the valve spring to remove and install the keepers? That’s the WAY harder part of doing this in the truck. I’m concerned for you because that’s what you should be asking about to do this job
 
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I appreciate the comments, but can someone familiar with the workings of the 2F engine please address the following question.

Can I safely replace each set of seals, 1 & 6, 5 & 2, and 3 &4 at the same time, and only turn the engine 3 times to find TDC and not 6?

The FJ is in my garage and can't be moved. The front end is on jack stands. My fan blade is plastic. I was unable to budge the engine with the fan belt. All of the plugs have been removed. The rocker rail has been removed. It took me an hour or more to get the # 1 piston to TDC yesterday, working by myself.
 
1979 FJ40ish said:
Can I safely replace each set of seals, 1 & 6, 5 & 2, and 3 &4 at the same time, and only turn the engine 3 times to find TDC and not 6?
Click to expand...
I'm thinking; No. You need the TDC (or close to it) and both valves closed. While cylinders 1 & 6 are at TDC at the same time, the valves don't close at the same time. You know how when you adjust valves you can only do 1,2,3 5,7,9 before you have to turn the crankshaft? I think the same thing happens here.
Can you get a socket on the crank nut? Two hands on the flywheel? Don't suppose you have the handcrank...
 
The nut on the end of the crankshaft does not accept a regular socket/wrench.

I can’t use a hand crank because I have a winch mounted on the front bumper.

I’m replacing the springs because I believe they are original and as long as I have to remove them to replace the seals I might as well, given how hard it is to get to them.

I might me able to turn the flywheel from underneath but I still would not be able to see the valves move at the same time.
 
As cruisermatt was implying, the hard part is compressing the springs and removing / installing the keepers. I used the compressor pictured and admittedly it was a pain. Note: when slipping the new seal over the valve stem, first slip a 2 inch piece of a soft drink straw over the valve stem. Slide the seal over the straw, once well past the keeper grooves, remove the piece of straw. The point is to not cut the seal lip on the sharp edged keeper grooves. Then tap the seal in place on the valve guide.
IMG_0684.webp
 
fjc-man said:
As cruisermatt was implying, the hard part is compressing the springs and removing / installing the keepers. I used the compressor pictured and admittedly it was a pain. Note: when slipping the new seal over the valve stem, first slip a 2 inch piece of a soft drink straw over the valve stem. Slide the seal over the straw, once well past the keeper grooves, remove the piece of straw. The point is to not cut the seal lip on the sharp edged keeper grooves. Then tap the seal in place on the valve guide.View attachment 4141300
Click to expand...
 
I’m comfortable with the procedure for removing the springs and seals. My problem is, while working alone, how to know when the pistons reach TDC while I’m at the back of the cruiser rotating the rear wheel.
 
Wrap a rope around the rear tire, a few times, run the ends up to the front. Pull on one rope to turn the wheel and engine one way, other rope end to reverse
 
Enough rope in the hole will prevent the need to be exactly at tdc and the valves will be supported. Do it in firing order. Yea you can use the rear wheel in high gear. Back the wheel up a little so you can pull the rope out.
 
Pighead said:
I'm thinking; No. You need the TDC (or close to it) and both valves closed. While cylinders 1 & 6 are at TDC at the same time, the valves don't close at the same time. You know how when you adjust valves you can only do 1,2,3 5,7,9 before you have to turn the crankshaft? I think the same thing happens here.
Click to expand...
I changed my mind. Once the rocker shaft is off you don't care where the cam is, all the valves are closed, so you can do 2 cylinders at once. I think.
 
What to compress the springs on an installed engine has always been my question. There never seems to be a definitive answer.
 
I have spring compressor my dad made back in the 50's. I think he used it on PW R-985's. Has a j shape hook on the end of the shaft. A few inches up are 2 half cup washers welded to the shaft. You take a section of chain and hook the J, the other end of the chain is bolted/hooked to the side of engine. Spring is centered in the cups - press down on the shaft - spring compresses grab the keepers....

Put like plastic peanuts in all the oil drain passages, cover the carb - last thing you want is drop a keeper down a hole.
 
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