Replacing push rod tubes

Rusty · Post by **Rusty** » Sun Apr 16, 2006 10:06 am

Hi - I need to replace some old (metal) push rod tubes with the new Nylon spring-loaded stuff & would like to do this w/o removing the heads. My thinking is as follows:

Remove rocker arm assy & push rods - this leaves the tubes empty which means I should be able to cut (grind) them in half & remove it; Does this make sense?

hitlers revenge · Post by **hitlers revenge** » Sun Apr 16, 2006 6:44 pm

Hi Rusty
It makes sense if you were just going to remove the tubes. BUT you obviously want to replace the tubes. This idea will not work when you put in the new ones as you will have to force them in. You will no doubt damage the tubes as well as the rubber sealing gaskets.
Cheers
Dave

Post by **eben** » Mon Apr 17, 2006 9:27 am

Rusty I suppose if you are thinking of using the telescopic ones it might work.... I dont know how far you can push them in however....Us Type IV guys are blessed by just needing to remover the valve covers and rocker gear + pushrods and you can take out and replace the whole tube by just pulling it through the head

Post by **Tony Z** » Tue Apr 18, 2006 8:25 am

Why the sping loaded ones??? Because you have a small leak you want to stop and you are too lazy to pull out the engine and replace them with cheaper originals. With the spring loaded ones, you pay a fortune and they will probably leak more than your old one does now.

Get stock ones with stock rubbers and you will have no problems for the next 15 years

Post by **calooker** » Tue Apr 18, 2006 8:48 am

Tony is giving you sound advice, the Nylon spring-loaded stuff will leak more than the standard tubes. Those Nylon spring-loaded tubes can't take the heat and will warp, I would only use those as a last resource if one of the steel tubes got damaged and was leaking badly, stay away from the Empi ones. I have a complete set at home I used them from new and had them on for less than 100 km I pulled the heads to fit the steel items, they leaked bad.

Post by **Tony Z** » Tue Apr 18, 2006 9:26 am

those items were originally intended for offorad applications when they hit a rock and split the tube. Cut the old tube out, remove the rocker shaft and pushrod, slip in the new tube, replace the pushrod (with a new one), install the rockers and get going again.

I have never run them, but have heard too many bad things about them.

Apparently there is a set by CSP (I think - German and British based company) who now make the tubes with lignum vitae (spelling??) O-rings, 3 of them. They can handle the heat more and will prob work as good as stock items until the O-rings go hard (year or two).

Rusty · Post by **Rusty** » Mon Apr 24, 2006 9:19 pm

Thanks to everyone for the responses - good advice thanks but bad news for me re. the nylon pushrod tubes. Any idea why these things leak?

Post by **Tony Z** » Tue Apr 25, 2006 9:10 am

O rings are not rated for the temperatures. They bend (maybe). Expansion??

Post by **calooker** » Tue Apr 25, 2006 10:25 am

They tend to go out of shape and then the middle O ring no longer seals properly so oil sloshing up and down the push rod tubes finds a way onto your paving. There is also too much play when the push rod tubes slide over each other causing them to flex and cause a bad seal against the O ring. Don't use them they WILL LEAK BAD.