| Author | Message | ||
| Robert W. Garven Jr. (Robertgarven)
Member Username: Robertgarven Post Number: 334 Registered: 2-2002 |
I used silicone grease on the o rings of my tire valve. You guys are lucky, the early 308's just have a cam seal mine aren't leaking however but the were hard to install, they kept popping out. My drag racer brother in law suggested using a auto center punch to make a line of center punches down the middle worked like a charm. I used 1211 3-bond on all my gaskets and no leaks at all from there at least. I learned this fro Ric Rainbolt apply a very thin layer to both sides maximum adhesion, minimum mess. Removing said part is hard! Rob | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1238 Registered: 8-2001 |
Thanks again Verell: I will post the pictures tomorrow. | ||
| Verell Boaen (Verell)
Intermediate Member Username: Verell Post Number: 1199 Registered: 5-2001 |
The emphasis should be on the 'could'. Hylomar is indicates when an o-ring needs to be held in place until it's sufficiently compressed so that movement is unlikely. Also in the very few problem cases where the o-ring needs some extra help to seal such as Hans mentioned. In most cases, o-rings do a great job of sealing without anything but a bit of oil (or water or coolant as the case may be) to help them slip into proper alignment. The compression forces on them ensure the seal. What always amazes me is how little an o-ring needs to be compressed to hold against very substantial pressure! I've never seen the inside of a TR cam cover, so I can't help with your 'square' o-rings question. Make a couple of photos of both the cam cover & head showing how they fit in & we should be able to answer your question. | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1237 Registered: 8-2001 |
Thanks Hans and Verell: This is starting to make sense. Then one could use either Hylomar, or Permatex #2 for O-rings in a static state?......just stay away from silicone. What about the square O-rings on the back side of a TR valve cover? These would appear to be static to me. At the bottom of the oil tank there is a cover, where the drain plug goes into. The cover attaches to the tank with a large O-ring. Would I use the hylomar there? Thanks again | ||
| Verell Boaen (Verell)
Intermediate Member Username: Verell Post Number: 1198 Registered: 5-2001 |
Hans, Permatex #2 has characteristcs that are very similar to Hylomar. Gooey, non-hardening, resistant to oil,fuel & coolant,seals gaps... Note, O-rings perform a sealing function, but are very different from true 'seals' that have shafts rotating inside of them and depend on their lips & the surface tension of the liquid being retained. True seals NEVER have anything but oil on their lips. The slightest contamination or nick & they're useless. HenryK, Search the archives for some posts on cam seals & o-rings by Dr. Ferrari, & a couple of other professional Ferrari technicians. They're consistent with what's posted here. | ||
| Hans E. Hansen (4re_gt4)
Intermediate Member Username: 4re_gt4 Post Number: 1710 Registered: 4-2002 |
Henry: The sealer/no sealer issue is totally dependant upon the specific application. As Verell suggested, cam O-rings are NOT the place for sealer. For some 'static' applications, sealer may be called for. But not most varieties of RTV. | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1236 Registered: 8-2001 |
This is getting confusing!!!!!!! It appears that most feel one should NOT use anything with O-rings, except for maybe a little oil lube. What do the Ferrari techs know that we don't? Or is it just overkill on their part? I find it very hard to believe they just don't know better!!! | ||
| Hans E. Hansen (4re_gt4)
Intermediate Member Username: 4re_gt4 Post Number: 1706 Registered: 4-2002 |
In general O-ring application where they don't need to float, Permatex #2, NON-HARDENING works well. Stays in place, stays 'gooey', resistant to oil, gas, antifreeze. The PO of my car used it on the distr O-rings, as that was the only way he could find to seal them. Since then, they've been installed w/o the Permatex and they leak! | ||
| Verell Boaen (Verell)
Intermediate Member Username: Verell Post Number: 1184 Registered: 5-2001 |
Henryk, Looks like the TR uses the same system a QV does. ie: a aluminum ring cam seal housing that's held in place by an o-ring. You absolutely don't want RTV in that particular o-ring groove. The housing needs to be able to 'float' into final position as the cam seal aligns itself to the cam's seal ridge. The grooves & o-ring must be clean, smooth, and very lightly oiled. I learned out about these grooves the hard way. The mechanic who did the major at the time I bought my 308 gooped my o-rings up the same way. The result was that the seals leaked like a sieve. Unfortunately, the 1st time I redid the seal job, I also put something in the o-ring grooves. In both cases the seal ended up off-center on the cam & leaked oil. When I re-did the job with just oil, I verified that the seal centered itself on the cam before installing the cam gears. Tom, I've been successfully using about a match-head sized dab of RTV where you use Locktite 518. However, I've used 518 it's a reasonable application for it. Wish I could go back and edit some of my earliest posts where I advocated using much more RTV than I do now. It's best used sparingly and cautiously. | ||
| Tom Bakowsky (Tbakowsky)
Member Username: Tbakowsky Post Number: 676 Registered: 9-2002 |
Thats not worst thing I've seen from a dealer!! I have seen the o-rings cut and then fed through,to avoid removing the cams!!. I just use a very small amount of permatex loc tight 518 sealer on the the corners were the gasket does not quite touch the surface of the cam seal housing. All you need is a small daab in the corners. You do not need to put any on the o-ring. | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1235 Registered: 8-2001 |
This is the reason I asked the question. I am doing a major service on my car.....enclosed is a picture of the inside of the cam end of the valve cover. This was done by the Ferrari dealer (sorry, no names), during the last service. It is somewhat hard to see, but there is a LOT of white silicone where the cam seals go into, especially the O-ring. What was the dealer thinking of?  | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 752 Registered: 5-2002 |
Silicone is the devil, so there are very few places I would use it, o-rings aren't one of them for the reasons Verell listed plus is squeezes out forming little rubber balls that are prone the break lose and plug oil passages. I think the only time I used it on the 308 engine was a VERY small dab the seal the ends of the cam cover gaskets. JMO | ||
| Verell Boaen (Verell)
Intermediate Member Username: Verell Post Number: 1176 Registered: 5-2001 |
If the o-ring can slip out of place, DO NOT USE RTV on it. RTV on rubber is slippier than a greased pig!! Seriously, O-rings that just fit into a shallow flat bottomed circular area milled around a hole have a strong tendancy to try to slip around and into the hole. RTV makes things even worse as it's extremely slippery while uncured. An example is the two oil passageways between the transfer case & the tranny that are sealed by o-rings. A little RTV there & you'll be wondering why you have an lubricant leak. However, not all sealants are incompatible with O-Rings. Hylomar is a good example. It's very tacky and never hardens. Hence tends to keep o-rings in place during assembly. Mazda shop manuals stat hylomar must be used in several places to retain o-rings. Most notably the rotor housing perimeter o-rings!!! When in doubt, if the o-rings are just being clamped into place, dry is probaly best. If there's any sliding involved, then a tiny amount of oil so they won't get scuffed. | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1233 Registered: 8-2001 |
Jim: It seems that people get carried away with this sealant thing!!!!!!! | ||
| Jim Avery (Boxer12)
Member Username: Boxer12 Post Number: 306 Registered: 6-2003 |
Hank, for what it is worth the Ftech who helped me with the leaky slave cylinder said not to put sealant on the rubber seal, but did put a very thin layer on the case around it. I notice when I removed it originally, however, that it had sealant on it, as you have observed. Good luck. Jim | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1231 Registered: 8-2001 |
I am in the middle of a major service on my TR. The square O-rings on the inside of the valve covers have a silicone sealant on them, placed there by the F dealer, during the last major. Some people told me NEVER to use sealant on a rubber seal......just oil and install. One gave the example of accidentally installing an oil filter in, with the old O-ring still in place....resulted in having 2 O-rings. He said it leaked badly.......rubber to rubber/silicone makes for a BAD seal!!!!! Others have stated that due to the stresses over the years, parts aren't 'perfect' in shape, and that a little silicone sealer is advised. I am now confused........!!!!!!! |