adriantr4 Posted June 27, 2023 Report Share Posted June 27, 2023 (edited) Hello I have been having long-term trouble with leaks from my TR4 rocker cover, and had tried regular gaskets and then in desperation bought a neoprene equivalent from Ebay. However, I think the actual problem is the early-TR4 rocker cover is actually a shade too big, plus had bowed out slightly. I have corrected this to get a slight bow inwards plus eased the rear mounting hole a shade to get it to sit a bit better. Now much improved. I think I have taken a step back with the neoprene gasket though as I induced a more major leak in a different spot. The gasket is well made and the correct shaped cross-section, but it unfortunately is a little too long. Trying to fit it is like trying to wrangle a large and uncooperative rubber band. Anyway, I have tried again and the couple of pics show what I have been up to. If this doesn't fix it then its back to a normal gasket. Fyi. regards, Adrian Edited June 27, 2023 by adriantr4 Quote Link to post Share on other sites
Ralph Whitaker Posted June 27, 2023 Report Share Posted June 27, 2023 Hi Adrian, I bought a neoprene gasket for my A35 van a while ago and gave up trying to fit it, every time I tried to tighten the rocker box nuts the damned thing popped out. Went back to the old rubber and cork glued to the rocker box with contact adhesive. I do the same with the TR, glue the gasket to the rocker box and use it several times before it gets too compressed and needs changing. Are you sure the oil is not coming down the pushrod tubes as that is a favorite spot for leaks. Ralph Quote Link to post Share on other sites
Motorsport Mickey Posted June 27, 2023 Report Share Posted June 27, 2023 1 hour ago, adriantr4 said: Hello I have been having long-term trouble with leaks from my TR4 rocker cover, and had tried regular gaskets and then in desperation bought a neoprene equivalent from Ebay. However, I think the actual problem is the early-TR4 rocker cover is actually a shade too big, plus had bowed out slightly. I have corrected this to get a slight bow inwards plus eased the rear mounting hole a shade to get it to sit a bit better. Now much improved. I think I have taken a step back with the neoprene gasket though as I induced a more major leak in a different spot. The gasket is well made and the correct shaped cross-section, but it unfortunately is a little too long. Trying to fit it is like trying to wrangle a large and uncooperative rubber band. Anyway, I have tried again and the couple of pics show what I have been up to. If this doesn't fix it then its back to a normal gasket. Fyi. regards, Adrian I seem to remember they use neoprene O rings for the seals on the large dirty water (drains) pipes. They cut the seals off what seemed to be a roll the size of the large wooden "cotton reel" (that they have LARGE dia electrical cables wound around ! If it were mine and despairing to get a seal the way it is, my next attempt would be to cut the seal across on the long sides with a very sharp razor blade and cut a small amount out sufficient to reduce it's overall size to stay inside the rocker cover spread ... maybe 3-4mm ? and then glue the cleanly cut square edges back together with Superglue. Give it a dab in the centre of the seal and press both ends together firmly keeping them in line. Mick Richards Quote Link to post Share on other sites
PaulAnderson Posted June 27, 2023 Report Share Posted June 27, 2023 Do Revington TR not stock a silicone gasket which might be better than neoprene ? They certainly used to. Paul Quote Link to post Share on other sites
ianc Posted June 28, 2023 Report Share Posted June 28, 2023 In 1998, Revington sold me a silicon rocker gasket (code IM91), which was produced being by an American whom I met at the IWE. However, it is no longer listed by Revington. It worked well, but now I have an alloy rocker cover produced by Tony Sheach - this has its gasket sitting in a groove in the casting, and the filler and the cast holding down nuts each have a silicon rubber seal. Because all exits are sealed, it requires a breather tube from one of the 2 screwed outlets along the side (the other being sealed). Ian Cornish Quote Link to post Share on other sites
Z320 Posted June 28, 2023 Report Share Posted June 28, 2023 Hi Adrian, are you shure your oil leak is from the rocker cover? It could also be from the push rod tubes? Ciao, Marco Quote Link to post Share on other sites
Charlie D Posted June 28, 2023 Report Share Posted June 28, 2023 I bought some 8mm neoprene sponge cord (several people sell it on eBay) and glued it to the standard rocker cover with Loctite MR5922 (Halfords). Where the ends meet I put a good dollop of the Loctite. I’ve taken the cover off two or three times in the past few years and never had leaking problems. The cord stays attached to the cover. Charlie Quote Link to post Share on other sites
adriantr4 Posted June 30, 2023 Author Report Share Posted June 30, 2023 Hello My rocker cover leaks have stopped. Adjusting the rocker cover for a better fit was a key step. Thanks to all the posters, all points noted. regards, Adrian Quote Link to post Share on other sites
MichaelH Posted June 30, 2023 Report Share Posted June 30, 2023 (edited) Moss do a silicone gasket one for the standard cover and one for the aluminium type rocker cover which I have Stick the silicone gasket to the cover with evostick and then coat the bottom with plumbers silicone and tighten it down I seals well , doesn't stretch like the cork ones and is easy to take off and replace with a further lick of the silicone cost £23 and I have only needed one since I bought it Michael H Edited June 30, 2023 by MichaelH Quote Link to post Share on other sites
Lebro Posted July 1, 2023 Report Share Posted July 1, 2023 I use standard Cork one, degrease & stick it to the head with wellseal, then smear some grease on top of it. It conforms to the shape of the cover on 1st fitting & has remained leak free after many subsequent removals. Bob Quote Link to post Share on other sites
Motorsport Mickey Posted July 1, 2023 Report Share Posted July 1, 2023 37 minutes ago, Lebro said: I use standard Cork one, degrease & stick it to the head with wellseal, then smear some grease on top of it. It conforms to the shape of the cover on 1st fitting & has remained leak free after many subsequent removals. Bob +1 Did this on my TR4 Race car, on and off dozens of times, no leaks. Mick Richards Quote Link to post Share on other sites
stillp Posted July 1, 2023 Report Share Posted July 1, 2023 +2 Quote Link to post Share on other sites
Andy Moltu Posted July 1, 2023 Report Share Posted July 1, 2023 13 hours ago, MichaelH said: Moss do a silicone gasket one for the standard cover and one for the aluminium type rocker cover which I have Stick the silicone gasket to the cover with evostick and then coat the bottom with plumbers silicone and tighten it down I seals well , doesn't stretch like the cork ones and is easy to take off and replace with a further lick of the silicone cost £23 and I have only needed one since I bought it Michael H Likewise. Glued it to the alloy rocker cover and no problems with leaks or squeezing out. On the 6 I had a groove machined in the cover an use an o ring type seal. Unfortunately the local member sold his machinery so couldn’t do the same on the 4A hence the silicon gasket. Quote Link to post Share on other sites
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