Felpro Permatorque Severe duty head gaskets

[Scary Fast atx]

Anybody ever have problems with these fancy new type gaskets?

More Information for FEL-PRO 505SD

I had a blown head gasket and replaced it with these new MLS looking severe duty head gaskets

Truck ran great a few times. Then when I was changing the transmission fluid/filter it started smoking white again.

I did a leak check on the coolant system and it's dropping from 15 to 13 psi in a matter of minutes...

Thinking these new gaskets had one of those rubber beads give up on me.

Planning on doing a leak down and also see if I'm getting any bubbles at the radiator, sucks so bad. I couldn't wait to get it back on the road

 

[Backyard]

just wondering did you get the heads checked for cracks and to see how true they are before replaceing gaskets? what motor is it ? Iron head? Aluminum head?

If you don't have the proper surface finish on the heads and the block the MLS gaskets will leak.

A friend of Mine found this out the hard way on an early LS iron head when putting MLS gaskets on.

 

[PrairieDrifter]

Did you retorque head bolts after a few hours or after heat cycle? I sure hope they work good I just put a set on the other day. I had a couple that needed retorqued.

 

[Backyard]

Hope your retorque works out for you. That being said you shouldn't have to ever retorque head gaskets in most cases. They are a set and forget for the most part. If you have to go back and retorque either something wasn't done right or something else is going on.

Not to say that it can't work do what works but generally not something that should have to be done.

Best regards

 

[fast 99]

Why MLS gaskets? Generic rebuilder gaskets work fine and are more forgiving.

 

[Backyard]

MLS gaskets have proven to be superior and tend to be where head gaskets have gone. They shine in the boosted applications. That being said I do agree an old motor as a daily I'd go with the standard gasket the motor came with. Take an apple out put an apple in for a daily.

 

[fast 99]

Yes, boosted applications need an improved gasket. Is that what is going on here? OP didn't say anything about that.

 

[Backyard]

Details were not given on the engine. I was just trying to hit all the marks for clarity

 

[Scary Fast atx]

just wondering did you get the heads checked for cracks and to see how true they are before replaceing gaskets? what motor is it ? Iron head? Aluminum head?

If you don't have the proper surface finish on the heads and the block the MLS gaskets will leak.

A friend of Mine found this out the hard way on an early LS iron head when putting MLS gaskets on.

its a 2bbl 305 with iron heads.
I didnt check them for cracks, I could see where the old head gasket failed and where the previous owner had used the head gasket sealer quick fix it bottle and it sealed for a while, so I was assuming it wasnt cracked.

I did check and they were flat within spec ~.003

These arent exactly MLS, but they do look like them, I got them on clearance, so thats why I got them, and supposedly they were better for older engines with looser tolerances. guess not???

Did you retorque head bolts after a few hours or after heat cycle? I sure hope they work good I just put a set on the other day. I had a couple that needed retorqued.

No I didnt retorque them at all, so you had to retorque your Severe duty gaskets?

Im really confused, I havent had to retorque a head gasket in years, at least since they started using the metal cores

Why MLS gaskets? Generic rebuilder gaskets work fine and are more forgiving.

they arent MLS gaskets, just look like them, they have those raised rubber beads around the coolant passages. The reason I got them was because they were on closeout on rockauto, and I read that they were "better" for older engines that had more wear and looser tolerances

 

[fast 99]

Have the heads checked and milled. New heads may seep until heat cycled a couple times.

Sounds like leak may be excessive.

I use 1 of the pellets below on new engines to avoid comebacks. They will not clog.

https://www.amazon.com/dp/B000QIH3C4/

 

[PrairieDrifter]

It's not a retorque necessarily. You're basically just checking to make sure each bolt Is still at its torque spec. Torque one head, prep the other, while the first sits, "retorque" the first then retorque the second. I had a couple bolts that either stretched or gasket compression.

I didnt need to do it I just don't understand why you wouldn't? I had a couple of bolts lose torque. Things generally move when they have a 17 bolts holding them down.

Nothing could have been done wrong, there's a torque spec and sequence. Everything was clean and fresh other than the block deck surface.

 

[Scary Fast atx]

It's not a retorque necessarily. You're basically just checking to make sure each bolt Is still at its torque spec. Torque one head, prep the other, while the first sits, "retorque" the first then retorque the second. I had a couple bolts that either stretched or gasket compression.

I didnt need to do it I just don't understand why you wouldn't? I had a couple of bolts lose torque. Things generally move when they have a 17 bolts holding them down.

Nothing could have been done wrong, there's a torque spec and sequence. Everything was clean and fresh other than the block deck surface.

Yeah it's definitely worth a shot. Fingers crossed it's just a loosened up bolt

 

[Ricko1966]

Okay don't know is this info. Is useful to anyone,but it's how I was taught at least 25 or 30 years ago, it works for me. I divide my torque value by 3 I torque one head to the first 1/3 value them move to the other head,back and forth 3 times then one last pass at final value after waiting 15 minutes,usually longer. I was told and it makes since to me that the block distorts with each pass,so walking back and forth is kind of a compensation method. I have to say head gaskets are so much better now.I remember retorques and having to the gaskets with hylomar or silver paint. It sucks there's still a few that that is required. PITA

 

[idahovette]

Agree with the multi pass philosophy. The third at a time and side to side has worked for me over the years, just let it rest between pulls. YMMV

 

[Bextreme04]

Stepped torque sequence is what the manuals call for. If you didn't take the heads down to the machine shop and have them surfaced and pressure checked after a blown head gasket, you have no idea what the problem is. It costs about $100 for me to do that locally and is well worth the cost to not have to do a repair twice.

I would also have scraped the block deck and then sanded the surface and checked with a precision straight edge to see if the deck surface is flat enough. I used a chevrolet performance gasket at my desired thickness to provide the quench and compression ratio I desired when I rebuilt my 350. Torqued stock replacement head bolts to the factory spec and never touched them again.