push rod tubes leaking oil

[Trevor S]

Hi all, a couple of the push rod tubes on the cylinder head of my TR4 engine appear to be leaking oil from their lower ends which then sits on the flat area immediately below the spark plug holes. It is actually a 4a cylinder head which I changed to when having unleaded valve seats fitted, but this was several years ago now. Any recommendations of an appropriate mastic or sealant which may do the trick ? I'd rather have to replace a mastic every couple of years than take the head off and have the tubes replaced, as I have no plans to take the head off for any other reason.

Any suggestions gratefully received.

Thanks in advance

Trevor.

[Dave Seer]

Hi Trevor,

 

This doesn't seem to be a particularly common problem, however it did hapen to me - I even went to the TRouble of buying a replacement set of pushrod tubes.

 

As you are no doubt aware, the orginal tubes were aluminium, and the replacements with which I was supplied are steel - for me this immediately ruled them out, especially as I could see no way to get the original tubes out without effectively desTRoying them. The solution I applied in the end was permanent, and involved no replacement parts, and no sealant.

 

What I did was simply to take the head off and flare the original tubes back into place. To do this, one needs two ordinary and prefereably identical sockets, a bolt of sufficient length complete with matching nut, and a couple of suitable washers. Choose sockets which have a nice smooth radiused flare to their outsdes, and are of such size that the "noses" are an easy sliding fit into the tubes, ensuring that the flares of the sockets seat on those of the ends of the pushrod tubes and not the cylinder head. Then simply slide one washer and one socket on the bolt, and slide the assembly into the offending tube. Slide the remaining socket into the opposite end of the tube and on to the bolt, fit the other washer and the nut and Tighten Judiciously! - meaing don't over tighten ! Otherwise you may run the risk of actually severing the existing flared ends from the main part of the tube. Repeat the operation for the remaining seven tubes, and you'll be done.

 

No Sealant ! No Steel ! No Replacament Parts ! No Problem !

 

Hope this helps.

 

Cheers

 

Dave