MB sealant set up time? MB sealant/timing cover vs. a shrinking head gasket - PeachParts Mercedes-Benz Forum

71Rcode · #1 02-18-2006, 07:33 AM

Hi all. I had just enough left in my year-old tube of MB sealant to complete an upper timing cover job. My question to you guys is --- this stuff is still VERY tacky after 24 hours (it's 35 degrees in the garage). How long should I wait before starting the car? I mean, it still has the consistancy as if I just sqeezed it out of the tube!

All old gasket material was cleaned pefectly, and scotchbrited. However, this is on a virgin headgasket motor, and I definitely am fighting the shrinking head gasket/U-shaped seal problem.

Oh yes. This is for my '95 E320. THANKS!!!

joel · #2 02-18-2006, 10:33 AM

I'd say buy a fresh tube. Think of all the trouble of redoing it

71Rcode · #3 02-18-2006, 10:51 AM

Hey Joel! Man, I've done this job four times in three weeks. I've got it down to a SCIENCE! Yes, the beating is cleaning up the old sealant. For sure. And I meant to say, I have two tubes on order. And it didn't make it here before the weekend. And, we've got to have the car operational monday...so I might be doing the job again next weekend...

A few tips for anyone -- and please follow at your own risk

1) I don't pull the cooling fan until after I remove the switchover valve and engine lift hook (two items bolted to the front upper cover). But, I remove the coolant crossover pipe too. Then, I remove the cooling fan. It's really easy to lock the cooling fan pulley (using a 1/4"? bent rod) with all these items out of the way.

I can pretty much have the front cover in my hand in 60 minutes.

2) The timing chain rail (with the guide pin) - it's easy to remove after the front cover is in your hand. I just use a 3/8" drive deep well socket (depending on how long your bolt is), a bolt that will thread inside the pin and a washer. Bolt/washer go through the ratchet end of the socket, the socket goes over the pin. Thread the bolt into the pin and tighten with a ratchet. The pin will slide out --- it's really quite long, and you may have the pull on the socket (with bolt going through) as you tighten the bolt.

If anyone is considering this job, it's really quite simple. You never need to pull the serpentine belt - thankfully. Just the valve cover. Simple stuff.

------------

I'd appreciate any more opinions on the sealant. Thanks again, Joel.

ILUVMILS · #4 02-18-2006, 01:53 PM

If you're talking about the "pinkish" colored stuff used to seal machined surfaces where no gasket is needed, it won't cure until it gets hot.

71Rcode · #5 02-18-2006, 02:43 PM

ILUVMILS, I'm talking about the stuff Phil sells here at Fastlane --- it's black in color. The part # is: 003-989-98-20-10 / A 003 989 98 20 10 /003989982010.

What is your experience using this stuff? It's been over 24 hours since I applied it - and I have a hair drier

on the area now (28 degrees outside in Dallas). Thanks!

ILUVMILS · #6 02-18-2006, 03:40 PM

I don't recall the part# of the MB stuff but you've probably got the same thing. It "cures" about as quickly as the job can be finished. Can you imagine an automotive sealant that required an excessive amount of time to cure before the car could be used

? By the way, if the stuff you've got is the same as MB sells, it works great.

ILUVMILS · #7 02-19-2006, 10:31 AM

Yup, I checked in WIS and 003-989-98-20-10 is the good stuff. Put the hair dryer away and drive the car.

71Rcode · #8 02-19-2006, 02:14 PM

ILUVMILS, well --- no luck. She's still leaking. But, I'm crossing my fingers/toes that once the new sealant arrives, and I do the job again, the stuff will cure much faster and will hold. If not, I'm pulling the head and will fix it for the last time..... man! Thanks again.

71Rcode · #9 02-21-2006, 09:09 PM

ILUVMILS --- Ok, my order arrived today and I put a gob of the new MB sealant on my work bench next to a gob of the old MB sealant. I also smeared a thin layer of the old stuff next to a thin layer of the new stuff.

Right out of the tube, the old MB sealant is very glossy in color - looks wet. The new tube of MB sealant is kinda matte in gloss. In about an hours time, the new stuff is really tacking nicely --- firming. THIS is what I've needed!

I think my old tube was just old, and something must've happened to it chemically. For my new tube, I'll keep plastic wrap over the cap/end, to keep the air out. And I'll keep it in the house instead of the garage.

BTW - the part number on the old and new containers are as you listed.

Thanks again.

ILUVMILS · #10 02-23-2006, 12:18 PM

That's interesting. Here at the dealer, we never have a tube sitting around long enough for it to go bad. Thanks for following up.

samiam4 · #11 02-23-2006, 01:12 PM

71Rcod,

Ya want to do another one? Just kidding! It's on my list when the weather gets warmer.

Michael

71Rcode · #12 02-24-2006, 09:21 AM

Man, this is depressing. Fifth time resealing the front cover gasket, and she's still leaking. Even with the great MB sealant, it's dripping just above the AIR pump on the lower corner where the head meets the front cover. So, it's time to pull the head.

---- OK, the cylinder head removal. This is a virgin motor (90k), and I have the new-style head gaskets in the garage. But, just want to be sure on the process.

The front cover/timing chain rail pin is NO problem. I'm a pro at that.

It really looks like I need to loosen the EGR/exhaust manifold pipe (RH side), remove the wiring/intake hose clamps from the (LH) side, mark the chain location on the timing gears, pull the air pump out of the way to loosen the chain tensioner, remove the exhaust sprocket, tie the chain to the side rail -- and pull the head.

I'm really unsure about:
* what on the intake side I need to pull. - I plan on pulling the head/intake/exhaust manifold together.
* and would really appreciate any tips anyone could pass along that would save me time.

Many thanks!!!

ILUVMILS · #13 02-24-2006, 10:54 AM

Take the intake manifold off. It's easy. Trying to pull the head with both manifolds attached will be a real juggling act.

71Rcode · #14 02-24-2006, 02:13 PM

ILUVMILS,

Thanks again. I really appreciate your advice. I'm already about 1/2 of the way. Hope you don't mind, but I have couple questions for you:
* what size/type socket/bit are the head bolts? I don't have anything with that many points. Not a problem, as I can run out later and get what I need. Just wanted to make sure to get the right thing.
* I'm going to break the two bolts holding each 1/2 of the manifold (cylinder 1-3 / cylinder 4-6). And will pull the head with the exhaust manifolds in place. Looks a bit daunting to remove all the manifold-to-head nuts. Does this sound good?
* Intake side -- Looks pretty straight forward. I moved the wiring harness out of the way, and am about to disconnect the fuel rail. Should I not do this? (taking all precautions, of course, to make sure the fuel system doesn't try and charge) Or, should I simply unbolt the intake manifold and leave the fuel rail in place?

From there, it looks really straightforward. Again, THANKS. I definitely want to do this right.

71Rcode · #15 02-24-2006, 06:14 PM

Ok, just to follow up. Pulling the head is whipping me

I removed the intake (broke the two hose/mount locations under the intake - will have to JB weld them back on. Had a terrible time removing the intake - the last bolt at the bottom next to the firewall is hidden by the fuel rail, or a part of the fuel rail. I'll have to go out later and get the correct socket for the head, but don't know if I'll find it on a Saturday.

Tomorrow morning, on the agenda:
* unbolt the exhaust manifolds from the head pipes
* remove the AIR pump (funny, just installed a rebuilt one three months ago) so I can get to the chain tensioner
* mark the timing chain
* loosen anything else small that I need to unbolt the head
* get the socket!

Wish me luck, guys.