whats up with permatex Hylomar sealant?

Hylomar is a more or less generic term for the blue polyester polyol–based sealant that you used.

I've used several different brands over the years (Valco is another brand). You can buy it online.

While it is fairly easy to use, never hardens and works somewhat well in some applications, cam covers usually develop leaks after a while when sealed with it.

A much better product if you are able to get all surfaces 100% clean and grease-free is Hondabond. It's a silicone type of sealant that can (if applied properly) give long-term leak-free service. The front side of a 308 is a challenge using anything.

 

I wouldn't change what you've already done, hylomar is "forgiving" because it doesn't harden and this makes it easy to work with. It's not the worst choice of sealant, just not my first choice for cam covers. A lot of the cam cover leaks that I've seen can be attributed to the skinny gasket "creeping" out and forming a little gap at the ends. This is particularly true if the cover is a little warped or overtightened. With a non-hardening sealant like hylomar, the paper has more trouble staying put. The directions recommend allowing the hylomar to dry a few minutes before assembly. This will let it firm up before the big squeeze.

As far as thermostats and water pumps, hylomar is the best choice. These parts get taken apart frequently and hylomar won't fight you at disassembly. It will contain coolant without problems. Usually the gaskets are small and don't move around.

 

Most motorcycle shops will carry Hylomar of some type.
Another interesting variation is Yamabond, (made for Yamaha) it works just like Hylomar, but is grey in color.
Blends in well on aluminum.

Reed H

 

Permatex super gray is the same thing as yamabond, etc. Great stuff!

 

What about Hondabond for valve covers????

I need to pick something up for mine here soon...

 

I have used used hylomar on my 308 valve covers for several years with no leaks. The best part is it is easy to get them apart for valve adjustments. If you are careful you can reuse the valve cover gaskets when using hylomar.
I use Elring Dirko for everything else.

Stacy

 

Been here!!!

They are replacing the Hylomar that we know and love here in the states with a new formula from across the pond. The part number is being redirected to this new batch. It is still up in the air wether or not the new will hold up to the old. You can still get your hands on the old stuff if you ask around. If you still have the part number ask your local store to see if their wharehouse still has some tubes of it. I found one place with over 100 tubes.

 

Permatex discontinued their version of "Hylomar" a few years ago which is good because it sucks compared to the genuine article which is still available.

http://www.hylomarusa.com/

I gotta disagree with the other posts regarding the silicone-based alternatives. Be aware that all silicones eventually breakdown when constantly in contact with hydrocarbons (e.g., gasoline and motor oil). Hylomar's main advantage is that contains no silicone and is impervious to hydrocarbons.

 

Hondabond works for valve covers, you can use that stuff for just about everything.

 

The white sealant you fought with is a white silicone that Ferrari favored for several years.

My experience with Permatex Hylomar on valve covers is that it works well & doesn't leak if used properly. You have to go back a few hours or a day or so after installing the valve covers & re-torque the cam cover nuts, if you don't do this the cam cover will eventually develop leaks(ask me how I know). Permatex Hylomar slow cold flows under pressure, so the initial torqueing needs to be repeated after it has had a chance to flow a bit. After the 2nd torqueing, the gasket seems to be held very firmly & the seal lasts.

I was surprised to read that it wasn't available as I just saw some on the shelf at an auto parts store. Guess I better grab it while I can. I'm about to pull the cam covers for a major & am planning on using Hylomar if I can locate it.

There seem to be at least 2 kinds of Hylomar:

The Permatex Hylomar doesn't have a solvent, it stays the same consistency no matter how long it's open to the air. Thus there's no limit on the working time.

Valeo Hylomar has a solvent in it & firms up significantly once the solvent flashes off. If it's flashed off before assembly, it's too firm to flow & seal properly. It works very well when sealing small areas like around the thermostat o-ring where you can apply it & then assemble the joint before the solvent finishes flashing off.

But I haven't had much luck with it on large areas like the valve covers, it flashes off & gets firm before you can get it applied all the way around. Ditto for using it where assembly can take awhile like on the bell housing o-rings.


I've never used the 'Hylomar' that finnerty's post links to, so can't comment from experience on it's characteristics. However, this statement from the web site makes me think it must be similar to the Valeo Hylomar:
"It is a polyester urethane based viscous putty blended with a solvent to make it easy to apply, whether pumped, applied in a tube, or sprayed in an aerosol. "

An alternative for specificly sealing your waterpump is to use #22071 PERMATEX WATER PUMP & THERMOSTAT HOUSING GASKET SEALANT

It's a grey silicone sealant specificly formulated to resist coolants. I've used it for years to seal the gasket between the water pump nose and the main water pump body.

 

Harley-Davidson have used Hylomar on some of their engines and that is where I got mine (after finding out Permatex didn't make their version anymore).

Harley part number: 99653-85

 

"Hylomar" is a registered trademark. The original formulation was developed by Rolls Royce many years ago for their own private use, and then it was spun-off as it's own, commercially available product ---- the link I posted is for this product.

Over the years, the name "Hylomar" has been licensed to several companies (including Loctite / Permatex) for use on their own products manufactured in general adherence to the Hylomar recipe. However, at least in the case of Permatex, the formulations are not identical. And, when you have used both (as I have), you can notice significant differences in their performance and shelf lives.

I have simply had much better results with the true Hylomar product. The only plus side to the Permatex version was that you could run to your local auto parts store and pick up a tube in a hurry (when it was still available). And, I always thought it was fine for less-critical jobs or jobs where you weren't tremendously concerned about long term performance.

Hylomar (again, I refer to the original) is actually available in variety of flavors for different applications --- including a non-setting, solvent-free type that has the same "get time" advantages of the Permatex version.

Also, I would add that when I contacted the folks at Loctite / Permatex about 1 year ago to inquire why I could no longer find their "Hylomar" at my local stores, they informed me that the final batch they produced was back in early 2005 --- and that they regarded any product still remaining on store's shelves to be "expired".

So here's the deal...

The original Hylomar is harder to find ---- speed shops, some specialized foreign auto parts stores, and online are likely to be your only sources. It is also considerably more expensive than the Permatex was.

But, trust me folks... it is worth the extra effort and expense... you will be very glad if use the original product. And, check out their website ---- you'll find that the original stuff is OEM for many impressive manufacturers (including our beloved Italian auto maker ).

 

Ahhh,
I should have kept reading. Now I need to get my order in.

 

I have used Hylomar for a long time on old British cars. Being a Jaguar enthusiast, I always bought Hylomar from the Jaguar parts supply companies like Moss Motors, SNG Barratt and Welsh Enterprises along with other repair parts, gaskets, etc. They all carried, and still carry, the European version of Hylomar (not the Permatex stuff). It's a bit more expensive than going to Pep Boys and picking up a tube of Permatex, but I have used that stuff on the Jaguars over the years with great success, and also on the Ferraris and it worked equally well.

 

Verell, you answered your own question before I could respond!

Here's another link that talks about the (2) main formulae --- "Universal Blue" and the "Advanced Formulation" (solvent-free).
http://www.hylomar.us/universal_blue.shtml

When you contact a distributor to place your order, just give them the product names. I've got a tube of each right in front of me, and I can't find a part number listed anywhere on them (must be a "British thing").

And, I realize Hylomar's own website states the Permatex stuff is supplied by them. But I'm telling you guys --- Permatex must do something to it in processing before they put it into their product tubes because it is different when you use it. Try using both for yourself and drawing your own conclusions.

Here are the (2) products from Hylomar ---- the solvent-free stuff is the "Advanced Formulation" ---- I use both versions for different applications...
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an unexpected place to get hylomar universal blue - www.harborfreight.com - $4

 

So is this the right stuff for valve covers?

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=97824

 

When i was an apprentice in a Jaguar race engine shop, thats all they gave us. It is a safe sealant to use in race motors.

 

Are the gaskets THAT bad that you need it??? The lil Ford Pinto valve covers in the racecar never needed any sealant and i;d chack valve lash a lot. If you need some H'mar lemme know, got some tubes of it and MUCHO other stuff sitting around here i no longer need (offer ONLY good to Birdman). H'mar worked great sealing the Hewland LD200 tranny in the race car, and i changed gears A LOT in to (note: is used no gasket, so you use H'mar).

BTW: that Harbor Freight price is EXCELLENT!

 

Your so right........been so long..........we used it primarily on the tappet bucket housing.........no gskts there........

 

Yeah... and H'mar is GREAT provided people follow the directions and WAIT a few minutes after applying, and then assembling the parts. Problems happen when you assemble too soon after spreading the stuff on the parts.