Change valve seal on 504 XN engine
- Thread starter harditk
- Start date
Typical way to change one stem seal
rxmechanic.com
of many
How to Replace Valve Seals Without Removing the Head | Rx Mechanic
we tend to agree with you, and the good news is with the right tools, you don't have to. We will show you how to replace valve seals without removing the head cylinder.
rxmechanic.com
Put compressed air into the cylinder. Do it straight from the compressor not via a ball valve or Tire gauge. Had it loose comp and nearly dropped a valve.
You’ll have to make a tool to get valve spring on and off.
Nothing is impossible depends how much time you have as fiddly.
If you decide to pull the head off chase a VRS kit first as they’re getting hard to find now. There’s a few in Oz on eBay. But abit pricey.
Hope this helps
BP
You’ll have to make a tool to get valve spring on and off.
Nothing is impossible depends how much time you have as fiddly.
If you decide to pull the head off chase a VRS kit first as they’re getting hard to find now. There’s a few in Oz on eBay. But abit pricey.
Hope this helps
BP
Thank you. I am aware of articles mentioning valve seals can be replaced using this method. But my mechanic argue there is rocker arm on top of the spring that cant be removed without removing head. I am not sure how true is this.
The easy way is to pull the head off but it can be done 4x time consuming and fiddly as hell.
You will need to get cylinder you are working on to have piston on tdc compression stroke so that both valves are closed.you will have to lock crankshaft so it doesn’t rotate when compressed air put into cylinder via spark plug hole (you will need an adapter to screw into spark plug hole to connect to air line)if car is a manual put it into 4th gear and handbrake on.if you back off valve adjuster you should be able to move rocker arm against shaft spring and rotate arm so it stays away from valve spring pad so as to access with spring compression tool.just make sure you have compressed air in cylinder before removing valve spring and during valve guide seal replacement and spring refitting…
I've not had a great deal of luck with the compressed air method.
My solution is a little different.
Remove spark plug, and rotate engine to the bottom of the stroke on the cylinder in question.
Feed as much thin nylon rope as you can into the cylinder. Lawn mower starter cord is perfect. Make sure you leave a tail hanging out of the spark plug hole.
Rotate the engine as far as you can by hand, so that the squished rope holds the valve closed.
Replace the valve seal.
Back off the engine a bit to relieve the squish of the rope, then just pull the rope out.
Refit spark plug, repeat for all cylinders necessary, job done.
My solution is a little different.
Remove spark plug, and rotate engine to the bottom of the stroke on the cylinder in question.
Feed as much thin nylon rope as you can into the cylinder. Lawn mower starter cord is perfect. Make sure you leave a tail hanging out of the spark plug hole.
Rotate the engine as far as you can by hand, so that the squished rope holds the valve closed.
Replace the valve seal.
Back off the engine a bit to relieve the squish of the rope, then just pull the rope out.
Refit spark plug, repeat for all cylinders necessary, job done.
I was going to mention the rope method but you beat me to it. 
It is standard practice for mower and chainsaw engines, not sure how well it translates to cars?
It is standard practice for mower and chainsaw engines, not sure how well it translates to cars?