English French German Italian Spanish

55 ES2 upper pushrod tube seals

Submitted by george_phillips on Tue, 20/06/2017
Forums
Singles
Just received s set of seals (upper and lower) for p/r tubes. The lower ones are again very thick whilst the upper ones don't seem to want to go over the raised lip on the underside of the rocker box. Trying to refit the cylinder head/rocker assembly over the O-rings by oneself is proving very tricky. Any clues? Would I be better off simply getting some fibre washes for the upper seals? George

Submitted by dan_field on Tue, 20/06/2017

Permalink

Hi George, not sure I understand the problem? Can you ease the top seal to fit over the lip? I'm still running the old ones and don't get any leakage there, at the bottom I have the rubber seals (square section) I make sure the the piston is on compression and haven't had any problem tightening anything down.

Dan

Submitted by ian_macdougall on Tue, 20/06/2017

Permalink

The usual upper seal for the pre '57 pushrods is a fibre washer. Just stick the fibre washers over the short stubs on the rocker box with your preferred sealer and the assembly should be easy. Any chance that you may have received a set of seals for the later engine? If in any doubt post a photo of them to help with the identification.

ian McD

Submitted by george_phillips on Tue, 20/06/2017

Permalink

Thanks guys. The seals that arrived bear the correct part number for the year ('55) namely C3/89 upper "o"ring and C3/88 lower "square" section washer. I must admit a prised off a fibre washer from the inlet upper seal but not on the exhaust. The description on the receipt from RGM states "Rubber seal early pushrod tunnel" - the lower one- and "Late (Top) pushrod "O" ring for the upper.Could I not just buy some fibre washers for the top seals? I made sure the piston was coming up to compression. I'll try the pic route tomorrow, Ian.CheersGeorge

Submitted by george_phillips on Wed, 21/06/2017

Permalink

Decided not to go to the faff of uploading pics as they would only show an O ring and a thick washer. I measured the O rings supplied by RGM and they are 19mm ID whereas the spigot over which they fit (upper end) is 24mm, hence the prob. I've ordered some fibre washers with an ID of 24mm so they should fit. The lower washers are 10mm thick and fit inside the p/rod covers OK. Let's hope this solves this silly problem. Thanks for your input. George

Submitted by dan_field on Wed, 21/06/2017

Permalink

Hi George, that sounds like a plan, mine certainly doesn't have any o rings and I can't imagine leaking at the top would be a big prob, I'm guessing there were fibre washers at the top to keep pressure on the bottom and more important seal?

dan

Submitted by george_phillips on Wed, 21/06/2017

Permalink

Sounds reasonable, Dan. When they arrive and have been fitted, I'll report back. It's just annoying that one orders the correct part number and a part that doesn't fit turns up. George

Submitted by george_phillips on Fri, 23/06/2017

Permalink

Parts have arrived and are now fitted. When I took a bit more light to the stubs under the rocker box I found that what I thought was just a dark rim was in fact an old fibre washer. I wasn't up to taking all the box off to clean round the mess I would make removing it so left it where it was (inlet) applied some Wellseal and put it all back together. The new square washers at the base get squashed out of recognition when the c/head is tightened up. Reset the tappets and fired her up. Sounded good. Now waiting for dry roads for a test run. George

 


Norton Owners Club Website by 2Toucans