Do all cam seals just leak?
 

Replaced these 3 times with MAZDA ones and still have some seepage. Its not a major leak but it leaks. I have inspected the cams and even replaced one (from another issue) and they still leak. I have 2 AN10 vents off the cam cover so I'm sure there not a blow by issue.

Not all of them. Just the ones in Mazdas.

lol

The odd thing to me is that they either do or don't in the BP's. You see people struggling with this repeatedly and others never even had so much as one incident.

I tried everything and never could get mine to stop leaking. It drove me crazy... now I have an LFX that doesn't leak. So an engine swap will fix it.

The first time I rebuilt my engine, I used generic parts-store cam seals. They never leaked one drop, even after multiple re-uses.

The last time I rebuilt my engine, I used "genuine Mazda" cam seals - they leaked like a sieve. I replaced them with at least 3 different seals from various manufacturers and various sources. It was only on the 3rd replacement that I got seals that actually sealed.

It's a crapshoot.

Mine have always leaked a bit too. Not enough to really cause a drip, it just make a bit of a mess in the area. Same on my old 1.6, and my 323GTX. I've heard putting RTV under the cam caps is suppsed to help, but I never tried it. I always used the RTV over the top (on the VC gasket) like the FSM states.

Tried that with Ultra Black and it didn't work.

Me too, no luck.

You know, if you take a close look a the design there is a coil spring that goes around the inside keeping the rubber next to the rotating metal. If you remove the spring and unwind the two ends, you can cut a small amount of spring off, reassemble the spring and put it back in the seal and install the seal (front-seat main, cam, etc). I have found this to slightly increase the force on the seal and leak don't occur. In my case anyway. Cheers

Another thing to check is to see if you've got a small groove worn into the seal seat on the cam. The simple fix for that is to not fully tap in the seal, give it a new surface to ride on.

Micro-sleeves slightly increase the diameter of the seal surface, are made out of extremely hard thin material (no more grooves in the seal surface ever), and have saved many a crank/cam for me.
I do not know if they are available for Mazda camshafts but if they are they would be the way I go to permanently fix a grooved shaft.
I usually offset the new seal anyways to keep it out of the original wear surface on a shaft that has no groove evident (the groove is there, you just cannot see it).
The seal recess has both a drain hole in the bottom and a vent hole in the top. Make sure both are clear. They are straight holes that can be cleaned with a drill bit.

I've never shortened the garter spring as 2manyHobyz suggested but I'm going to take apart the next seal I replace (the old one) as the idea has merit. Thanks!

I always lubricate my seals with Stay-Lube marine grease (Smurf blue! part number SL3121) and I have taken seals back out 10 years down the road and the blue stuff is still in the seal!
I've never had it attack a rubber product.
The really good seals (factory stuff) will sometimes come pre-lubed and I clean the factory grease out and replace it with the "Smurf Goo" as I have had phenomenal luck with it.

I clean seal surfaces on the shafts with purple 3m scotch-brite and WD40. This usually looks "micro-polished" when I'm done. It can "hide" the smallest of grooves and it cleans up the old oil "rings" great.

I check seal drag first with both shaft and seal dry, should have medium drag and then buttered up. 1/3 the drag of the unlubricated is what I expect.
If it's too tight or too loose I find another manufacture for the seal.
I normally prefer factory stuff but the above test still applies.
This drag test really requires experience (on poorly fitting seals) to know when it feels right but if a beginner thinks it's off it probably is...

I use a super tiny amount of the "brown shit" Aviation Form a Gasket (part 3h, new part # 80019) for the head to cap parting line. The 4 oz bottles last me a couple of years, it will last an enthusiast 10+.
Keep the threaded cap and the threads on the top of the bottle super clean to allow re-opening down the road.
The amount I use is tiny and I keep it as far away from the journal as possible. I don't want this stuff to touch the shaft. When it's right I will get a tiny perfect bead at the outer part line after torqueing which I will clean off with a bit of B12.
The brown shit is easily cleaned up with B12, even hard 10 year old brown shit.

I DO NOT use RTV here! The only RTV I use is the grey stuff (Permatex Ultra-Grey) as 3 decades ago I had far too many "come backs" with any other color.
The new black or red stuff might be perfectly fine now but I am a creature of habit and when something just flat works I seldom change it.
The only place I use the grey stuff on a Mazda motor is the "corners" on a valve cover gasket and the oil pan. When you use any RTV the surfaces have to be "medically" clean and you should not allow any oil to touch the RTV for at least 4 hours and overnight is far far better.

A serious gouge in the shaft that passes through the seal contact area is a death knell for the seal. A micro-sleeve is a REQUIREMENT here.

I haven't had a seal that I have installed leak in 30+ years now (knock on wood) but I am an ---- pinheaded bitch when It comes to the installation.
I've installed maybe 6 sets of front engine seals in Miata's as of now but I've installed hundreds of seals in other crap over that past 40 years. No leakers for the past 30...

I type too much but this was my 2 cents on this issue.
Hope it helps someone down the line...

A quick internet search turned up this for the standard cam seal.
SKF 99134 Hardened Stainless Speedi Sleeve for Shafts - Shaft 34mm | eBay
But nothing for the larger VVT seal 47mm. If your VVT actuator has bad grooving on it it should probably be replaced anyways...
The E-bay listing is a bit on the expensive side and I'd check with a bearing supply house before pulling the trigger on that. I want to pay $20-25 for micro sleeves not 45 but I'm a cheap bastard.

As Ronald Regan said "Trust but verify" you should do the same before purchasing that micro sleeve. Verify the diameter on your camshaft before ordering and check a BS house first!

@technicalninja ; Great info! I will file this away for the next time I blow up my engine.

Checked and they looked fine. I have also replaced the cam (for other reason) and it did not change.

Lots of good into. Thanks

So leak is annoying me so bad I have to fix it. 3 sets of Mazda seals leaked so far what other brands you guys have luck with? I will follow all advice and see if I get a better result this time. I know for sure I will never have a rust issues under this car.

For me the key is getting the bore the seal goes in surgically spotlessly clean. Several cycles of clean rag and brake parts cleaner.

Then with a perfectly clean, new mazda cam seal, I smear a tiny amount of ultra grey rtv on the bore in the head that the seal goes into, a tiny bit on the OD of the seal, and then press it in.

Never had one leak, done it this way 8-10 times over the years.

I have fixed many leaks and most are caused by a damaged cam journal from a novice that previously replaced the seals or a leak under the cap. The proper way to change the seals is to remove the cap. Its very unlikely that one could damage the cam using this method. Under the front edge of the cap, between it and the head there should be a small amount of silicone.